# Do Carburated Turbo Systems Suck? Yes or No



## velardejose (Sep 9, 2004)

I found this:
http://home.att.net/~jason510/turbo.htm
I am only considering a draw through config
My plan is to use my current stock e16 (9:1 cr), a stock e16 intake manifold with a ga16 carb (blow through - all vents sealed I know) with this mentioned bov and fixed ignition advance, maybe around 20 crankshaft degrees btdc, and this ct9 turbo
I want 6 - 7 pounds of boost for this entry/learning project
I'll build a 8:1 e16 for more boost if things go as planned
I would like to hear your comments
Thanks in advance


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## Zen31ZR (Mar 24, 2004)

velardejose said:


> I found this:
> http://home.att.net/~jason510/turbo.htm
> I am only considering a draw through config
> My plan is to use my current stock e16 (9:1 cr), a stock e16 intake manifold with a ga16 carb (blow through - all vents sealed I know) with this mentioned bov and fixed ignition advance, maybe around 20 crankshaft degrees btdc, and this ct9 turbo
> ...


 The problems I know of with draw-through include excessive wear on the turbo compressor blades, which are constantly being bombarded at incredible speeds with what basically amounts to solid particles (atomized fuel). I saw what happened to a turbo compressor blade in a setup which used water injection pre-turbo (basically the same thing, though water is a bit heavier), there was almost nothing left of the compressor blade after 6 months time. I think your best bet is blow-through, at least for turbo longevity.


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## morepower2 (Apr 19, 2002)

[email protected] said:


> The problems I know of with draw-through include excessive wear on the turbo compressor blades, which are constantly being bombarded at incredible speeds with what basically amounts to solid particles (atomized fuel). I saw what happened to a turbo compressor blade in a setup which used water injection pre-turbo (basically the same thing, though water is a bit heavier), there was almost nothing left of the compressor blade after 6 months time. I think your best bet is blow-through, at least for turbo longevity.


Don't even attempt to turbo a carburated engine.


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## BII (May 13, 2004)

morepower2 said:


> Don't even attempt to turbo a carburated engine.


Why even say that? Its not impossable, in fact its not even that complicated. Granted, for most people Turbocharging an EFI-equipped engine is easier, but lots of carb'd cars are turboed, some from factory (like the Corvair).


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## velardejose (Sep 9, 2004)

Thanks for the data 
Look at the Renault 5 Alpine, it was a draw through config
I found a place where I can have a copper 2.5 mm thick headgasket made
As much as I know the stock headgasket has 1 mm height (after torque is applied)
I need 1.5 mm more height to drop the cr from 9:1 to 8:1
That would allow more boost


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## morepower2 (Apr 19, 2002)

bII said:


> Why even say that? Its not impossable, in fact its not even that complicated. Granted, for most people Turbocharging an EFI-equipped engine is easier, but lots of carb'd cars are turboed, some from factory (like the Corvair).


Sure its posible but the results will absolutly suck, go ahead and do it, don't say I didnt warn you. The driveabilty will suck, maintaining the proper a/f ratio will suck. The engine will drive poorly and be unreliable. It won't make much power. Port fuel injection is what made turbocharing practical.


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## morepower2 (Apr 19, 2002)

velardejose said:


> Thanks for the data
> Look at the Renault 5 Alpine, it was a draw through config
> I found a place where I can have a copper 2.5 mm thick headgasket made
> As much as I know the stock headgasket has 1 mm height (after torque is applied)
> ...


That is the wrong way to drop CR. You loose all the quench in the cylinder and increse the propensity to detonate at a given compression ratio. Get proper piston made.

Your project is looking for trouble. You would be better off and spend less money going NA.


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## velardejose (Sep 9, 2004)

You are right...
I'll think things twice before jumping in...
Maybe a fuel injected ga16 could do it
Thanks for answering


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## dburone (Apr 2, 2004)

morepower2 said:


> Sure its posible but the results will absolutly suck, go ahead and do it, don't say I didnt warn you. The driveabilty will suck, maintaining the proper a/f ratio will suck. The engine will drive poorly and be unreliable. It won't make much power. Port fuel injection is what made turbocharing practical.


I´m sure that mpfi is better, but not sure that its easier, you guys have to understand we have different realities, and there are places where carburated is better. A carb is easier to fix and lot cheaper.
My setup is starting to work out very well and its a e16s turbo with carb.
I had a chevy 350 efi, and after it stopped working here there wasnt anybody who could fix it, so it went carbed and it never stopped working.
Sorry, but a carb is better sometimes!!!


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## James (Apr 29, 2002)

we should title this thread free for all and move it to general...


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## velardejose (Sep 9, 2004)

Its still related to force air into an engine, be it carbed or not
(please apologize me for my english)


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## BII (May 13, 2004)

James said:


> we should title this thread free for all and move it to general...


Or separate this new discussion from the original thread.


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## BII (May 13, 2004)

morepower2 said:


> ...The driveabilty will suck, maintaining the proper a/f ratio will suck. The engine will drive poorly and be unreliable. It won't make much power. Port fuel injection is what made turbocharing practical.


Its driveability is no worse than any carb'd car, which with a properly tuned carb is fine. The engine will not run poorly or be any more unreliable than any other well-tuned vehicle. As far as power, there's plenty of Corvairs, Volkswagens, Toyotas, Datsuns, etc. that would very much disagree.

Carburation is simply another way of delivering fuel, granted its much easier to swap out bigger injectors and send your computer out to get reprogrammed when turbocharging, but there's no rational reason to firmly assert (as many many do, not just you morepower) that carb + turbo are incompatable, impossable, or "unreliable."


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## Zen31ZR (Mar 24, 2004)

morepower2 said:


> That is the wrong way to drop CR. You loose all the quench in the cylinder and increse the propensity to detonate at a given compression ratio. Get proper piston made.
> 
> Your project is looking for trouble. You would be better off and spend less money going NA.


Not to mention, the thicker the headgasket, the easier it is to blow. Some exceptions can be made for metal HGs, though. The only correct way to lower CR is to replace pistons.


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## Zen31ZR (Mar 24, 2004)

bII said:


> Its driveability is no worse than any carb'd car, which with a properly tuned carb is fine. The engine will not run poorly or be any more unreliable than any other well-tuned vehicle. As far as power, there's plenty of Corvairs, Volkswagens, Toyotas, Datsuns, etc. that would very much disagree.
> 
> Carburation is simply another way of delivering fuel, granted its much easier to swap out bigger injectors and send your computer out to get reprogrammed when turbocharging, but there's no rational reason to firmly assert (as many many do, not just you morepower) that carb + turbo are incompatable, impossable, or "unreliable."


 Even if reliability and driveability be left out, it's still a poor choice for a performance application..........


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## morepower2 (Apr 19, 2002)

velardejose said:


> You are right...
> I'll think things twice before jumping in...
> Maybe a fuel injected ga16 could do it
> Thanks for answering


You are way better off doing that.


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## morepower2 (Apr 19, 2002)

dburone said:


> I´m sure that mpfi is better, but not sure that its easier, you guys have to understand we have different realities, and there are places where carburated is better. A carb is easier to fix and lot cheaper.
> My setup is starting to work out very well and its a e16s turbo with carb.
> I had a chevy 350 efi, and after it stopped working here there wasnt anybody who could fix it, so it went carbed and it never stopped working.
> Sorry, but a carb is better sometimes!!!


A carb is never better under any circimstances. Your turbo carbed E16s is not fast or reliable. EFI can always be fixed as long as competent people are around to fix it.

This sounds harsh and I don't mean it to be that way but thats how it is.


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## morepower2 (Apr 19, 2002)

bII said:


> Its driveability is no worse than any carb'd car, which with a properly tuned carb is fine. The engine will not run poorly or be any more unreliable than any other well-tuned vehicle. As far as power, there's plenty of Corvairs, Volkswagens, Toyotas, Datsuns, etc. that would very much disagree.
> 
> Carburation is simply another way of delivering fuel, granted its much easier to swap out bigger injectors and send your computer out to get reprogrammed when turbocharging, but there's no rational reason to firmly assert (as many many do, not just you morepower) that carb + turbo are incompatable, impossable, or "unreliable."


Bullshit. A draw through system needs a huge disproportionate accelerator pump shot to avoid bogging. Once you get the pump shot high enough and thats a big if, it runs all eraticaly for quite a while due to huge wetting issues. You can't intercool a draw though system and you have compressor blade damage issues. Distribution problems are severe as well.

I don't think you have ever turbocharged a car otherwise you would know not to argue. Ever drive a datasun with a crown turbo kit or try to get it to run right? Ever work on a Rockstock ford drawthrough turbo kit? Or a BAE for that matter? What company made a carburated toyota turbo kit? maybe BAE? I am old enough to have worked on these.These things would never run with any sort of reliabilty or boost levels as todays turbo systems. None of these could even run with a well built NA motor and a modern turbo system could bite these up chew them up and spit them out.

Carburators must be so extensivly modifed to run draw through that their air bleeds and emulsion tubes as well as main jets must be totaly altered to work even halfway right. On carbs besides webers, del ortos and mikunis, this means soldering up holes, redrilling them and a whole lot of grief even if you know what you are doing. This is not stuff for a beginner on his first turbosystem and no one in their right mind would even do it today.

Tell you what, bring out a draw through crabed, or even blow through turbo anything that you built, lets go to to the track, turn the boost up to 20 psi or heck lets be fair, even 10 psi and see whos car is still running after 20 minutes of running.


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## Zen31ZR (Mar 24, 2004)

Here is a page on blow-through and draw-through applications. Nice little article, it even touches on some points that Mike did not. 

HERE


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## Marc Z31 (Jul 25, 2004)

chimmike said:


> close to the combustion chamber won't work as well as equal length simply because, as you know, not all of your cylinders fire at the same time.
> 
> the equal length takes those individual pulses and smooths them out into useable flow and thermal expansion for spinning the turbine.
> 
> ...


Someone actually tried this on a SR20. The stock manifold VS shortest possible VS equal length, and the equal length not only spooled faster, it made more FLAT torque and FLAT HP all across theRPM range. There is a reason that the really high HP NA cars have equal length tubular manifolds, to increase the scavengine effect. On a turbo car this is not as important, but still useful. If you want a higher EGT, wrap your exhaust. Wraping it actually works BETTER than a ceramic coating, but it corrodes the manifold faster, as it will hold moisture. Equal length SS manifold=Teh hotness.


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## James (Apr 29, 2002)

Javier at full race did the comparison of log versus equal length. He has a cool video somewhere too.


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## velardejose (Sep 9, 2004)

Really interesting data... Thanks!
This is it:

http://www.wakesports.com/full-race/index.php?showtopic=249


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## morepower2 (Apr 19, 2002)

Marc Z31 said:


> Someone actually tried this on a SR20. The stock manifold VS shortest possible VS equal length, and the equal length not only spooled faster, it made more FLAT torque and FLAT HP all across theRPM range. There is a reason that the really high HP NA cars have equal length tubular manifolds, to increase the scavengine effect. On a turbo car this is not as important, but still useful. If you want a higher EGT, wrap your exhaust. Wraping it actually works BETTER than a ceramic coating, but it corrodes the manifold faster, as it will hold moisture. Equal length SS manifold=Teh hotness.


If you wrap a turbo manifold, it will crack, not from moisture but from oxidation induced from the heat.


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## morepower2 (Apr 19, 2002)

[email protected] said:


> Here is a page on blow-through and draw-through applications. Nice little article, it even touches on some points that Mike did not.
> 
> HERE


Hehehe, reminds me of the crap that we went though, blowing out throttle seals, warping throttle plates, sinking floats, spewing oil out of the compressor seals and starving bearings, leaning out on top end and blowing up due to not having a fuel pump with enough pressure then blowing up the needle and seat of the carb.

It only really works at really low boost and then not so well.

If you can do better with carbs, try and we can have a dyno power off, race or whatever. I'll put money that the EFI car can outpower the carbed one by 70% or more.


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## Yoda (Jan 8, 2005)

morepower2 said:


> Bullshit. A draw through system needs a huge disproportionate accelerator pump shot to avoid bogging. Once you get the pump shot high enough and thats a big if, it runs all eraticaly for quite a while due to huge wetting issues. You can't intercool a draw though system and you have compressor blade damage issues. Distribution problems are severe as well.
> 
> I don't think you have ever turbocharged a car otherwise you would know not to argue. Ever drive a datasun with a crown turbo kit or try to get it to run right? Ever work on a Rockstock ford drawthrough turbo kit? Or a BAE for that matter? What company made a carburated toyota turbo kit? maybe BAE? I am old enough to have worked on these.These things would never run with any sort of reliabilty or boost levels as todays turbo systems. None of these could even run with a well built NA motor and a modern turbo system could bite these up chew them up and spit them out.
> 
> ...



Drawthrough is easier, and you're right you can't intercool, but blowthrough is reliable. EFI is better and can be a better choice, if circumstances permit.


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## Zen31ZR (Mar 24, 2004)

morepower2 said:


> Hehehe, reminds me of the crap that we went though, blowing out throttle seals, warping throttle plates, sinking floats, spewing oil out of the compressor seals and starving bearings, leaning out on top end and blowing up due to not having a fuel pump with enough pressure then blowing up the needle and seat of the carb.
> 
> It only really works at really low boost and then not so well.
> 
> If you can do better with carbs, try and we can have a dyno power off, race or whatever. I'll put money that the EFI car can outpower the carbed one by 70% or more.


 I won't take that bet because I know better.  We touched a bit on carbed turbo applications in my old turbo class as well, suffice it to say I have no interest in beating my head against a wall trying to make it work at anything above 5 or so psi boost....... To my knowledge, and what was stated in the class, thats about the upper limit for even a somewhat reliable system. It's so archaic and worthless I doubt even NASCAR(and it is the _king_ of archaic technology) would use such a system. Nope, EFI is _much_ better.


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## Yoda (Jan 8, 2005)

morepower2 said:


> Hehehe, reminds me of the crap that we went though, blowing out throttle seals, warping throttle plates, sinking floats, spewing oil out of the compressor seals and starving bearings, leaning out on top end and blowing up due to not having a fuel pump with enough pressure then blowing up the needle and seat of the carb.
> 
> It only really works at really low boost and then not so well.
> 
> If you can do better with carbs, try and we can have a dyno power off, race or whatever. I'll put money that the EFI car can outpower the carbed one by 70% or more.


70%, seems like too much. There was an article a while back where they got similar power out of NA motors, although the EFI equipped car had better response and a flatter power curve.

Again if circumstances permit, EFI should be used, no doubt. But the prevailing attitude that it is impossible or not suited for perfomance/race applications is unfounded.


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## Zen31ZR (Mar 24, 2004)

Yoda said:


> 70%, seems like too much. There was an article a while back where they got similar power out of NA motors, although the EFI equipped car had better response and a flatter power curve.
> 
> Again if circumstances permit, EFI should be used, no doubt. But the prevailing attitude that it is impossible or not suited for perfomance/race applications is unfounded.


Not impossible , but the effort is generally not worth the minimal power gains.


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## Yoda (Jan 8, 2005)

[email protected] said:


> Not impossible , but the effort is generally not worth the minimal power gains.


Drawthrough running 11 PSI on a 510


9.8 PSI 675 HP

ETs in the 10s with a four cyl FORD? Not too bad

Yes, EFI is better, but if circumstances do not permit a Fuel injection conversion, you are not doomed to unreliablity or low performance. Moreover, lots of Motorcycle guys run carb'd turbos with great success as well.

No one's trying to build something that will outrun a Supra in the 1/4 or anything, but there is hope for the "old school" crowd that are more or less stuck with carburation.


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## Zen31ZR (Mar 24, 2004)

Yoda said:


> 9.8 PSI 675 HP


Might want to read that one again. EFI was added to it. So it's not a pure carbed turbo setup and therefore not part of this discussion.


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## Zen31ZR (Mar 24, 2004)

Yoda said:


> ETs in the 10s with a four cyl FORD? Not too bad


Like to see longevity and reliability on that car. It's a draw-through application, so he can make some decent power, but there's massive wear and tear on the compressor wheel, to be sure. I'll also bet money on that car being a bigtime trailer queen, those kind of cars don't earn my respect at the track. Drive it to the track, race it, drive it home, that's how it should be done.


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## Zen31ZR (Mar 24, 2004)

Yoda said:


> Drawthrough running 11 PSI on a 510


THis guy is also gonna have serious compressor wheel wear issues, he is also using water drip (Can't call it injection on that motor) and relying on the turbo for atomization. The article also states he's used it in that configuration for 1000 miles. Give it about another 2000 or 3000 and he'll start having problems.

Good finds, nobody ever said it couldn't be done, but I highly doubt any of those engines is, A: going to be running a year from now, or B: is going to be using the exact same turbo that it has right now. There will be intense wear issues with all the draw through systems mentioned and the one blow through system is relying on EFI to prop it up. I'd say that really you haven't proven anything but our point.


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## morepower2 (Apr 19, 2002)

Yoda said:


> 70%, seems like too much. There was an article a while back where they got similar power out of NA motors, although the EFI equipped car had better response and a flatter power curve.
> 
> Again if circumstances permit, EFI should be used, no doubt. But the prevailing attitude that it is impossible or not suited for perfomance/race applications is unfounded.


It is not imposible and it is also not suitable for performance, if performance to you means reaching anywhere near the power potential of turbocharged engines.

If you think I am wrong, take my challange.


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## morepower2 (Apr 19, 2002)

Yoda said:


> Drawthrough running 11 PSI on a 510
> 
> 
> 9.8 PSI 675 HP
> ...


For the 510, I'd like to see that one make more than a couple of laps at speed around a road course without blowing up. Also [email protected] mph is slower than a stock Sentra SE-R. 

The carburated turbo 327 was having problems emptying out its float bowls at any sort of decent boost, upping the fuel pressure would have caused needle and seat with bowl venting problems. Pressurizing the whole carb in a might might work but fuel delivery is always a huge problem to overcome in boost carbed cars. The carb simply cant handle the fuel pressure needed. Sidedrafts start packing it in at about 6-7 psi of fuel pressure and Holleys don't like much more than 12 psi before you run into problems. The needle and seat also have trouble flowing enough. Note that they got rid of the carb because it was not working. If you tried to even make a 1/4 mile pass at this power level, it would have gone BOOM.

The Mustang is a drag racer, I bet the throttle response sucks and that motor would never live around a road course. The motor probably runs super rich on the bottom end with no driveabilty. But its a drag racer so who cares. Thats still the best results I have ever seen from a carbed turbo.


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## Zen31ZR (Mar 24, 2004)

The Mustang seems to be very close to the SVO setup, I wonder at the carberation gig. Old tech EFI systems like that aren't hard to find and work on, unless you're intensely stupid, and for cheaper than the cost of a brand new carb if you know where to look. I consider myself pretty old school, and yet I know my way around an EFI system as well as anyone else. I have to wonder at the reference of "the old school crowd being more or less stuck with carburation". I don't see that at all. Even 3rd world countries have and can work on EFI systems, so that statement is outrightly false.


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## BII (May 13, 2004)

[email protected] said:


> The Mustang seems to be very close to the SVO setup, I wonder at the carberation gig. Old tech EFI systems like that aren't hard to find and work on, unless you're intensely stupid, and for cheaper than the cost of a brand new carb if you know where to look. I consider myself pretty old school, and yet I know my way around an EFI system as well as anyone else. I have to wonder at the reference of "the old school crowd being more or less stuck with carburation". I don't see that at all. Even 3rd world countries have and can work on EFI systems, so that statement is outrightly false.


Ask dbourne about the availability of EFI in some countries. And no one is talking about buying a new carb, there are plenty available. Sometimes the expense of fabricating parts or adapting an EFI kit makes carburation easier and cheaper. Moreover, carburation has been around a while, and if that is what your expertise is, you'll probably have more success with it than with EFI. A carb is easier to adapt and match than an EFI kit intended for another vehicle, which is why many choose that route. I suggest people go and look at the discussions in the e-serfies subforum and go to the Datsun 1200 forum (don't remeber the URL, google it, you'll find it). Also search around for motorcycle setups using turbos and Corvairs using turbos (also look for early 80s Buicks and Volkswagen Beetles, all using carburation and turbo setups). People in Puerto Rico, South America, England, they use carb'd turbos, and their engines aren't "blowing up" or only lasting a year.

For balls out track performance most will go to EFI regardless of costs or troubles; for street+track the costs/hassles involved in converting to EFI may not make it the best choice for some. For many in the States, where parts and electronics are readily available and decent prices, this is the best choice.

I designed a blow-through for my e-series motor before Charles (HybridDET) sold me his EFI manifold, which is diffcult to find in the US. If I hadn't found it, I would've had to use a carb in a turbo setup.

EDIT: Here's the discussion on the E16s turbo dbourne's been working on.


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## Zen31ZR (Mar 24, 2004)

I think some manufactureres still use carburation because it's still cheaper to produce than EFI. The Suzuki Samurai was carburated at a time when most other vehicles were EFI, same with the Geo Metro and several other cars sold here just a few years ago. Dodge still sells the Ramcharger in Mexico, on the Durango chassis, and it is still carburated. However, with US emission laws being what they are, you won't find to many carb setups on vehicles still required to pass current US emissions standards.
Motorcycles at this point are exempt from emissions, at least in my state, as are Corvairs due to their age. All of the motorcycle turbo setups I know about are EFI, even as far back as 1982 with the CX500T-CX650T. Pretty much all _factory_ motorcycle turbo setups have been EFI. 
I also was not talking about the entire world, I was stating EFI technology's availability at it stands in the US, where even the most remote junkyard is likely to have such parts available in it, nor is an auto parts store generally too far away..... 
Using carbs with turbos is pretty much unecessary and not nearly as effective as using EFI. Throttle body injection is pretty much the bottom of the rung for EFI systems, basically a direct off-shoot of carburation ,and I'd consider using such a system before I'd ever consider using carburation, on a blow through turbo system. Not sure what you mean by a system intended for one vehicle cannot be used on another, I've never had any problems adapting systems for useage. You can use pretty much any EFI system on any engine, long as the number of cylinders is correct. 
As far as the longevity issues, I'd like to see your sources for determining carbed turbo reliability, and where you get your maintenance facts from. You stated people in South America and England etc use carbed turbos and their systems last for over a year? Completely untouched? Maybe at less than 2000 miles a year, I might beleive that. Not at the 15,000 a year I tend to drive. Classic Corvairs generally aren't daily drivers, so I tend to think they also don't count. Show me one carburated blow-through/draw-through system that can match the mileage I do on a yearly basis without constant maintenance and I'll believe you. 
Carburated turbo systems are nothing more than a curiousity, for people that have a lot of time to waste. My time is a bit more precious than that, so I'll stick with my EFI turbo systems.


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## BII (May 13, 2004)

Factory motorcycle systems are FI true, but aftermarket turbos for carb'd bikes abound. As far as reliability, poke around in google, tons of info on carb'd/turbo exsists on the web. A former boss of mine drove one of his modded Corvairs (with an aircooled/drawthrough setup, for those that don't know) like 5-6,00 miles a year, a good part of it in LA traffic, had few problems.

I'm not saying EFI is worse, it is in fact better, if its feasible in your particular case. And if EFI is not the best/most feasible option, you're not doomed to unreliablity or engine failure running a carb/turbo setup. That was my point all along.


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## Zen31ZR (Mar 24, 2004)

bII said:


> Factory motorcycle systems are FI true, but aftermarket turbos for carb'd bikes abound. As far as reliability, poke around in google, tons of info on carb'd/turbo exsists on the web. A former boss of mine drove one of his modded Corvairs (with an aircooled/drawthrough setup, for those that don't know) like 5-6,00 miles a year, a good part of it in LA traffic, had few problems.
> 
> I'm not saying EFI is worse, it is in fact better, if its feasible in your particular case. And if EFI is not the best/most feasible option, you're not doomed to unreliablity or engine failure running a carb/turbo setup. That was my point all along.


 5,000-6,000 miles a year is half what the average person drives. And you said with _few_ problems, how about _zero_ problems for the comparable EFI turbosystem. Most EFI systems can be trouble free for many years, look at the system on my Z for instance. 165,000 miles and has never been touched. Technically still hasn't , because even though the engine has been apart, the EFI system is still all original. You just simply can't compare longevity and reliability between the two types of systems, it's apples and oranges.


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## BII (May 13, 2004)

Few, probably none, I didn't sit there with him the whole time. And yes, in general EFI is more reliable. Does that mean Carb'd vehicles are not reliable at all? No.

EDIT: My weber 32/36 DGV (NA) has provided me flawless operation for 5,000 miles now, despite not being tuned 100%. Granted, TC would complicate issues, but I would not dismiss it entirely given its excellent performance so far (and great reputation).


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## Zen31ZR (Mar 24, 2004)

bII said:


> Few, probably none, I didn't sit there with him the whole time. And yes, in general EFI is more reliable. Does that mean Carb'd vehicles are not reliable at all? No.
> 
> EDIT: My weber 32/36 DGV (NA) has provided me flawless operation for 5,000 miles now, despite not being tuned 100%. Granted, TC would complicate issues, but I would not dismiss it entirely given its excellent performance so far (and great reputation).


Plain carb setups are not the issue here , though. The world had carburators for over 50 years before the first factory fuel injection system popped up (in regular automobiles). Carbs and such by themselves are pretty reliable.


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## morepower2 (Apr 19, 2002)

[email protected] said:


> The Mustang seems to be very close to the SVO setup, I wonder at the carberation gig. Old tech EFI systems like that aren't hard to find and work on, unless you're intensely stupid, and for cheaper than the cost of a brand new carb if you know where to look. I consider myself pretty old school, and yet I know my way around an EFI system as well as anyone else. I have to wonder at the reference of "the old school crowd being more or less stuck with carburation". I don't see that at all. Even 3rd world countries have and can work on EFI systems, so that statement is outrightly false.


Not SVO but those horrible first generation turbo 2.3 liter mustangs from 1979-1980. The SVO's came later and they were EFI and intercooled. Much better.


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## morepower2 (Apr 19, 2002)

bII said:


> Ask dbourne about the availability of EFI in some countries. And no one is talking about buying a new carb, there are plenty available. Sometimes the expense of fabricating parts or adapting an EFI kit makes carburation easier and cheaper. Moreover, carburation has been around a while, and if that is what your expertise is, you'll probably have more success with it than with EFI. A carb is easier to adapt and match than an EFI kit intended for another vehicle, which is why many choose that route. I suggest people go and look at the discussions in the e-serfies subforum and go to the Datsun 1200 forum (don't remeber the URL, google it, you'll find it). Also search around for motorcycle setups using turbos and Corvairs using turbos (also look for early 80s Buicks and Volkswagen Beetles, all using carburation and turbo setups). People in Puerto Rico, South America, England, they use carb'd turbos, and their engines aren't "blowing up" or only lasting a year.
> 
> For balls out track performance most will go to EFI regardless of costs or troubles; for street+track the costs/hassles involved in converting to EFI may not make it the best choice for some. For many in the States, where parts and electronics are readily available and decent prices, this is the best choice.
> 
> ...


Street turbos and drag racing turbos don't face the challanges of having to hold together very long. Yeah I bet that your car was neither fast nor relaible in carbed form. I bet my turbo Sentra can make 70% more horsepower than your carbed turbo sentra and not will blow up when run hard under boost for periods as long as 1/2 hour.

I am willing to put my money where my mouth is. Are you? Bring out that carbed turbo car to a real race track and lets run it against my EFI turbo. Try to keep up with me, try to run 1/2 hour straight. Try to beat me and stay running, I bet you won't be running or will be far behind.

Bring money. If you blow I might feel sorry for you and let you keep your money.

Either that or you might beat me and teach me a few new things


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## Zen31ZR (Mar 24, 2004)

morepower2 said:


> Not SVO but those horrible first generation turbo 2.3 liter mustangs from 1979-1980. The SVO's came later and they were EFI and intercooled. Much better.


Oh yeah those ones....nevermind.......


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## BII (May 13, 2004)

This new discussion is interesting but should be branched off into a new thread, we've gone too far off-topic of the original thread.


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## Zen31ZR (Mar 24, 2004)

bII said:


> This new discussion is interesting but should be branched off into a new thread, we've gone too far off-topic of the original thread.


Still has to do with turbocharging, and we established how a turbo really works.......finally. It probably should be split. Unfortunately, I don't have any control in this section.


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## velardejose (Sep 9, 2004)

Yes
But efi is not an option with this particular project I am into...


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## morepower2 (Apr 19, 2002)

velardejose said:


> Yes
> But efi is not an option with this particular project I am into...


can I ask why?


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## velardejose (Sep 9, 2004)

Yup
1. Cost of a decent efi system
2. Engine swapping regulations way too complicated
I'll post pics


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## morepower2 (Apr 19, 2002)

velardejose said:


> Yup
> 1. Cost of a decent efi system
> 2. Engine swapping regulations way too complicated
> I'll post pics


what are your expectations as far as power, reliabilty, driveabity? How much money do you have to spend?


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## velardejose (Sep 9, 2004)

Daily driver
Around 50% hp more
Goal boost: 6-7psi
Got the turbo and bov for free
It is a learning project mainly, like those fuel press regulator things, ignition advance issues that are really interesting
Its clear to me that for a serious power aplication efi is a must


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## morepower2 (Apr 19, 2002)

velardejose said:


> Daily driver
> Around 50% hp more
> Goal boost: 6-7psi
> Got the turbo and bov for free
> ...


can you get a GA16DE manifold, wire harness and ECU? What sort of turbo is this, what kind of car did it come from?

You are proably better off with a NA bolt on build.


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## velardejose (Sep 9, 2004)

A monopoint efi could solve my problem?


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## morepower2 (Apr 19, 2002)

velardejose said:


> A monopoint efi could solve my problem?


Multiport is better but a single point is better than a carb because it can handle higher fuel pressures.

This with a rising ratre fuel pressure regulator and a higher pressure pump might work ok for low boost


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## velardejose (Sep 9, 2004)

Car/engine is a e16 b22 (sentra coupe)
Turbo is a CT9 (starlet/glanza turbo as much as I know)
Bov from a toyota glanza
I'll do some more research before jumping into it


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## BII (May 13, 2004)

Read this.

In this case they are installing a centrifugal supercharger, but the same principles apply, since we are talking about forced induction and carbs.


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## Zen31ZR (Mar 24, 2004)

bII said:


> Read this.
> 
> In this case they are installing a centrifugal supercharger, but the same principles apply, since we are talking about forced induction and carbs.


6 psi, about what I would expect on a blow-through system. Says it can run to 10 psi but 6 is recommended. 
See this is a different animal altogether, superchargers behave differently than turbos do. A supercharger would do better in a draw-through application as well, than a turbo would, you won't have the wear issues because a supercharger isn't spinning anywhere near as quickly as a turbo.


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## Zen31ZR (Mar 24, 2004)

morepower2 said:


> Multiport is better but a single point is better than a carb because it can handle higher fuel pressures.
> 
> This with a rising rate fuel pressure regulator and a higher pressure pump might work ok for low boost


The Starion/Conquest had such a TBI/turbo system. About 10 or so pounds of boost I beleive, I forget exactly how much. Works well enough for some of them to be pretty fast, but a multiport upgrade is in order at around 280 Hp, and it's a huge pain........


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## morepower2 (Apr 19, 2002)

bII said:


> Read this.
> 
> In this case they are installing a centrifugal supercharger, but the same principles apply, since we are talking about forced induction and carbs.


Of course blow thoughs require pressurising the whole carb but you have issues with the floats sinking and the needle and seat blowing up, sticking or not seating. Driveabilty is still not that great. You see the boost is limited to 6 psi?


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## morepower2 (Apr 19, 2002)

velardejose said:


> Car/engine is a e16 b22 (sentra coupe)
> Turbo is a CT9 (starlet/glanza turbo as much as I know)
> Bov from a toyota glanza
> I'll do some more research before jumping into it


The other issue is that draw though systems require an active seal which is usualy a spring loaded carbon chunk. If you try to draw through a turbo thats not made for running a depressed inlet pressure, you end up sucking a lot of oil into the motor which promotes detonation. Your turbo does not have this sort of seal, it has a dynamic seal.


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## BII (May 13, 2004)

morepower2 said:


> Of course blow thoughs require pressurising the whole carb but you have issues with the floats sinking and the needle and seat blowing up, sticking or not seating. Driveabilty is still not that great. You see the boost is limited to 10 psi?


No, You pressurize the carb to avoid such problems. And I've seen pressurized 4 barrels run 20psi (there was an AMC board were a guy had an engine, it was a while ago when I read it, I'll try and find it.) The point is what would the charger have to do with the carb? No one has successfully explained why such a combo is so aweful as it has been demonized here. Blow-through setups _do not_ have to be pressurized, unless you want to run high boost. At low boost levels you're floats and needles are OK.

Anyone ever heard of Gale Banks? He was turbocharging 350s using carbs back in the 60s, did alright IMO.

Let me repeat, if EFI is a feasable option, do it please. But to discredit carburation and furthermore provide no logic as to _why_ it is so horrible is not right. The same principles applied to using a centrifugal supercharger/carb setup can be used in a turbo setup.


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## morepower2 (Apr 19, 2002)

bII said:


> No, You pressurize the carb to avoid such problems. And I've seen pressurized 4 barrels run 20psi (there was an AMC board were a guy had an engine, it was a while ago when I read it, I'll try and find it.) The point is what would the charger have to do with the carb? No one has successfully explained why such a combo is so aweful as it has been demonized here. Blow-through setups _do not_ have to be pressurized, unless you want to run high boost. At low boost levels you're floats and needles are OK.
> 
> Anyone ever heard of Gale Banks? He was turbocharging 350s using carbs back in the 60s, did alright IMO.
> 
> Let me repeat, if EFI is a feasable option, do it please. But to discredit carburation and furthermore provide no logic as to _why_ it is so horrible is not right. The same principles applied to using a centrifugal supercharger/carb setup can be used in a turbo setup.


Their is pleny of logical evidence why carbs are vastly inferior to the point of being horrible in this thread if you read it. Just because you read that someone did something on the internet doesnt mean that it worked well.

Gale Banks was using a pressurised Holly in his V8 kits but he also had several stages of enrichment using injectors (I belive it was three) to make up for the carbs shortcomings. When C and D magazine had a project Banks Camaro that they were trying to break the 200 mph mark with they went though several motors.

I'll prove to you first hand that carbed turbos don't make anywhere near the power of EFI ones nor are reliable in the context of a DIY aftermarket kit. You are in so cal, lets take it to the dyno, I bet my Sentra will make at least 150% more wheel hp power than your motor. This is generous to make up for the fact that my motor is bigger and is of a more modern design. Lets go to the track as well. Lets see if your sentra can stay within 2 laps down from mine and not blow up in 15 laps of willow springs. This is again generous. This means I have to lap you twice to win and you have to still be running at the end of the session. Pretty hard to do in only 15 laps.

I think you will neither be only two laps down nor running by the end.

You are only encoraging someone to ultimatly build something that is neither fast or relialbe.


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## BII (May 13, 2004)

morepower2 said:


> Their is pleny of logical evidence why carbs are vastly inferior to the point of being horrible in this thread if you read it. Just because you read that someone did something on the internet doesnt mean that it worked well.
> 
> Gale Banks was using a pressurised Holly in his V8 kits but he also had several stages of enrichment using injectors (I belive it was three) to make up for the carbs shortcomings. When C and D magazine had a project Banks Camaro that they were trying to break the 200 mph mark with they went though several motors.
> 
> ...


First I'm not encourging anyone to "build something that is neither fast or relialbe." <-- you still haven't told me WHY this statement is so true.

Second, quit being childish "callling people out." to run at willow. First, my turbo is not built yet (I'm still working out things design-wise, no one builds parts for webers, only Holly and Demon, it seems), and I have an EFI manifold and FI, I don't have the electronics, which is hard to come by. Your car is 10 years older than mine, and suspension, etc., is light years ahead, not to mention wear, etc. I was going to rig it up using the EFi components I have now, but I'll make it using a carb, the hell, its not like B12s are hard to come by, I can make an EFI one later.

Third, Banks wasn't using EFI to enrich anything in the mid 1950s-1960s. Mechanical FI was around, but certainly not _electronic_ fuel injection.

Lastly, tell me the reason(s) WHY it "the car won't last, its unreliable, you can't drive, it, blah, blah, blah?" All asserted this fact, you haven't proved it. All you've said is EFI is better, which is true, but not the question.


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## morepower2 (Apr 19, 2002)

bII said:


> First I'm not encourging anyone to "build something that is neither fast or relialbe." <-- you still haven't told me WHY this statement is so true.
> 
> Second, quit being childish "callling people out." to run at willow. First, my turbo is not built yet (I'm still working out things design-wise, no one builds parts for webers, only Holly and Demon, it seems), and I have an EFI manifold and FI, I don't have the electronics, which is hard to come by. Your car is 10 years older than mine, and suspension, etc., is light years ahead, not to mention wear, etc. I was going to rig it up using the EFi components I have now, but I'll make it using a carb, the hell, its not like B12s are hard to come by, I can make an EFI one later.
> 
> ...


First off you keep on insisitng that carbs are a good alternative for turbo motors, they are not and its annoying that you keep on posting this. I mean if you can't afford to go efi, you should probably not even bother to turbo your car. Second their is so much information that you are wrong in this thread that you are blind to facts. You keep insisting that their is no information posted here but Ballistix and myself have ticked off quite a few. Perhaps you might want to read some of the posts here.

Since you don't get it here are very good reasons.

Draw through-
1. unless the turbo has an active seal, as spring load carbon seal, the depressed pressure at the compressor caused by the carb will cause oil to bypass the seal, oil causes detonation, fouls plugs, etc. Most turbos have non contact dynamic seals and cannot take low inlet pressures. Active seals have a lot of drag and increse lag.

2. Exceedingly poor throttle response and part throttle driveabilty due to the huge wetted area before the fuel/air can reach the manifold. Requires a huge acclerator pump shot, beyond what most carbs can provide. Poor cold start and driveabilty when cold for this reason as well. This sucks

3. Poor fuel distribution, turbo can cause puddling and seperation of a/f mixture. This can be very dangerous for the engine

4. Cannot run intercooler.

5. Most carbs cannot provide a decent fuel curve over the range of NA and boosted operation. Carb will run rich at bottom end if jetted for boosted operation. Difficult modifcations must be done to the power valve cuircuit, etc beyond the scope and experiance of most people.

6. Most carbs don't have a needle and seat large enough to flow enough. Upping fuel pressure to increse delivery can cause fuel level in float bowl problems due to the needle and seat failing or blowing off the seat.

7. Compresser blade eriosion is an isse, compressor wheels can't take being hit with liquid at 100,000 rpm. Wheels can be nickle plated to help but hardly anyone makes draw trhough turbos with nickle plated wheels and active seals anymore because their so many better choices of how to do things now.

8. No ignition managment. You need to retard the spark with boost to aviod detonation. Gotta run an aftermarket ignition with some sort of boost dependant retard function. At best this is a crude 2D approximation of what the engine needs.

Blow though-

1. carburator has severe problems with fuel reversal, shaft leakage, shaft and throttle plate damage and stuff unless carb is placed in a sealed box with a boost dependent fuel pressure regulator. Sealed box makes things complicated and hard to work on. Sealed box is hard to package as well. Sealed box is semi complicated and expensive fabrication.

2. Even in a sealed box, fuel delivery is a problem. Floats crush and sink under pressure. Needle and seat cannot flow enough, upping fuel pressure causes needle and seat to jam and fail causing bowl flooding.

3. Most carbs cannot provide a decent fuel curve over the range of NA and boosted operation. Carb will run rich at bottom end if jetted for boosted operation. Difficult modifcations must be done to the power valve cuircuit, etc beyond the scope and experiance of most people.

4. No ignition managment. You need to retard the spark with boost to aviod detonation. Gotta run an aftermarket ignition with some sort of boost dependant retard function. At best this is a crude 2D approximation of what the engine needs.

Most of these issues severly suck and many of them create situations dangerous for the engine, especialy if you don't know what to look out for and how to deal with it. With carbs due to these issues you are limited to very low boost levels.

The Banks system used a pressurised holley carb and 3 stages of hobbs switch controled fuel injectors using a fixed duty cycle cold start type fuel injector. The carburator alone could not provide a proper fuel curve.

I am calling you out to prove to you that you are wrong since you are blind to facts. You car will not have good driveabitly, it wont make good power or be fast and it won't be reliable. This will prove it to you. When your car blow up you might get it. I am often at the dyno or track anyway, so it really isnt any trouble to me, just meet me there. 

You have never turboed a car, your car doesnt even run with a turbo, yet you refuse to listen to people who have many years of experince, one with a formal education in turbo systems and who have been their and done that. I'd say go ahead and do it. You will make a blustering 130 whp if you are lucky, and your car will run like crap, if its a draw through, your turbo will suffer from blade errosion if it lasts that long, it will suck oil through the compressor seals, have poor throttle response, poor cold start and cold driveability. It will probably detonate and break something since you have no spark management and grossly inadiquate fuel managemnt. 

Yes it will probly run and it will make more power than stock, but it won't be fast it won't be reliable. Maybe you will diddle around and not go into boost much and declare that your system is reliable and great. Its dispointing that you have to resort to calling me childish because you can't admit that you are wrong or listen to advice from some of the more experianced members of this forum. Since you are set in your way just do it and don't say we didnt warn you.

Just don't insist that carbs are good for turbos and don't give that advice here when you really have no practical experiance and have not done it.


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## BII (May 13, 2004)

Wow 10 rep points, you are childish, at least I'm right about something. 

I never said carbs are a good alternative, only that if that if you look at costs/benefits, you are not doomed to having a poor running system as you keep insisting.

And no you have not shown me why a carb'd turbo is inherently doomed to failure, which was my original question. I guess if the "NF Gods" saw so, then it must be so, worldwide experience be damned. Oh well. I guess you put me in my place, without even answering my guestion, damn that's power.


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## morepower2 (Apr 19, 2002)

bII said:


> Wow 10 rep points, you are childish, at least I'm right about something.
> 
> I never said carbs are a good alternative, only that if that if you look at costs/benefits, you are not doomed to having a poor running system as you keep insisting.
> 
> And no you have not shown me why a carb'd turbo is inherently doomed to failure, which was my original question. I guess if the "NF Gods" saw so, then it must be so, worldwide experience be damned. Oh well. I guess you put me in my place, without even answering my guestion, damn that's power.


Fostering advice that can be harmful to other readers engines is grounds for negative rep. Its only 2 points not 10. If the 12 reasons for why carbs don't work well listed above don't register with you then you really don't get it.  Like I said, go ahead and build your system and find out first hand why carbs suck. I have tried to get other peoples problems to run well in the past and its diffcult and often the only satisfactory solution was to run piddly boost. You havent even gotten your project running. You have no experiance at all other than what you read somewhere. If you diddle around with really low boost and you don't drive hard and rairly get into boost, you will probably pat yourself on the back and congradulate yourself as to how right you are. Just do it and come back with dyno charts and other results showing how right you are. Chances are you won't have many positve results to share.


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## morepower2 (Apr 19, 2002)

velardejose said:


> Car/engine is a e16 b22 (sentra coupe)
> Turbo is a CT9 (starlet/glanza turbo as much as I know)
> Bov from a toyota glanza
> I'll do some more research before jumping into it


The turbo is probably sized ok for your applcation. The BOV is not to critical for boost levels this low.If you run a carb, then don't exceed more than 5-6 psi.

Be very careful in looking for lean conditions under boost. Preferabily use a wideband A/F meter.

Blow thoughs generaly work better but require a sealed box for the carburator, a 1:1 step up boost referenced fuel pressure regulator and a higher pressure fuel pump. With all of this expense its better to run the single point injection which I think you already have, a boost depedent regulator with a 8:1 step up, a higher pressure volume fuel pump and an aftermakret ignition with a spark retard function. Don't exceed 80 psi of total fuel pressure. You might be able to run as much as 8-10 psi this way but be very care and pay close attention to the a/f ratio as you go past 6 psi.


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## velardejose (Sep 9, 2004)

Thanks a lot both of you morepower and bII for the data
Things are a lot clear to me now, we have a couple TOYota glanza runnin 21 psi and a 200 sx running 18 psi (this one is really fast)
I would manage to get this e 16 engine running, but would be severely limited by boost, and would never be able to keep the pace of those mentioned cars
If I go turbo, I would like to get 'turbo' power (read lots of)
Thanks again


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## Zen31ZR (Mar 24, 2004)

bII said:


> Wow 10 rep points, you are childish, at least I'm right about something.
> 
> I never said carbs are a good alternative, only that if that if you look at costs/benefits, you are not doomed to having a poor running system as you keep insisting.
> 
> And no you have not shown me why a carb'd turbo is inherently doomed to failure, which was my original question. I guess if the "NF Gods" saw so, then it must be so, worldwide experience be damned. Oh well. I guess you put me in my place, without even answering my guestion, damn that's power.


 10 rep points? You don't seem to be missing any more points than when I saw your sidebar yesterday. As far as I'm concerned, Mike K. exlpained things pretty well in his response above. I haven't seen any reply from you yet on the matter. 
The majority of examples of high powered systems I've seen pulled out as an attempt to justify the reliablity and power of carbed turbo systems, are basically only one-offs, built for a single purpose, usually drag racing where throttle response and driveability is not an issue (You're at WOT all the time, even off the line). The Corvair system you mentioned is likely highly overbuilt, to provide some semblence of reliability, but he'll probably still have problems after a few thousand miles with no maintenance. 
The part that you don't seem to get is that we are maintaining that you cannot at anytime approach the reliability and longevity of a factory efi system with a carburated turbo system. Carburated factory turbo systems run incredibly low pressures that could probably be offset by using higher compression pistons and stronger internals, I am referencing the Corvair here, a car which has few good running examples on the road at this date, most of which have either been converted to other engines or are highly maintenanced and treated with TLC. I know at this point of no factory carbed turbo systems in production, nor any in the last 10 years, nor of any with a lot of running examples on the road, which should tell you something. I would not hesitate to say there are many more running carburated only cars from the 60s on the roads then there are of Corvairs or any other older factory turbo carburated systems of any type, blow-through/draw-through, whatever you can find. 
Carbed turbo doesn't make sense in a modern application, not with efi parts cheap and plentiful and adaptable to any application with a little work.

I stand behind what Mike K has said in response to you, what I don't understand is both your persistance, and lack of tangible evidence to support your side of the argument.


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## chimmike (Oct 17, 2002)

bII, your idiocy is getting you on a fast track of getting kicked off here.


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## BII (May 13, 2004)

[email protected] said:


> 10 rep points? You don't seem to be missing any more points than when I saw your sidebar yesterday. As far as I'm concerned, Mike K. exlpained things pretty well in his response above. I haven't seen any reply from you yet on the matter.
> The majority of examples of high powered systems I've seen pulled out as an attempt to justify the reliablity and power of carbed turbo systems, are basically only one-offs, built for a single purpose, usually drag racing where throttle response and driveability is not an issue (You're at WOT all the time, even off the line). The Corvair system you mentioned is likely highly overbuilt, to provide some semblence of reliability, but he'll probably still have problems after a few thousand miles with no maintenance.
> The part that you don't seem to get is that we are maintaining that you cannot at anytime approach the reliability and longevity of a factory efi system with a carburated turbo system. Carburated factory turbo systems run incredibly low pressures that could probably be offset by using higher compression pistons and stronger internals, I am referencing the Corvair here, a car which has few good running examples on the road at this date, most of which have either been converted to other engines or are highly maintenanced and treated with TLC. I know at this point of no factory carbed turbo systems in production, nor any in the last 10 years, nor of any with a lot of running examples on the road, which should tell you something. I would not hesitate to say there are many more running carburated only cars from the 60s on the roads then there are of Corvairs or any other older factory turbo carburated systems of any type, blow-through/draw-through, whatever you can find.
> Carbed turbo doesn't make sense in a modern application, not with efi parts cheap and plentiful and adaptable to any application with a little work.
> ...


Yes, the amount of rep points change, at this point its clear its an arbitrary system anyways.

Drawthrough systems are bad, at one time they were the popular choice because the fabrication was easier. But they are dangerous since you are compressing gasoline along with air, this is probably why many hot rod guys back in the day shunned turbos and went with high-compression engines or superchargers. Blowthrough carb setups are safe, and with a sealed, pressurized carb, the owner can achieve some level of added power safely and reliably. As much as EFI, no. Some owners are not looking to build a vehicle with that sort of performance, otherwise you'd start with something else. Some of you decided that I was arguing against using EFI, I was not. If your attitude is "why turbocharge a carb'd car?" the same attitude is made against tuning four cylinder, FWD cars, this question of why bother, and the reasons are plenty. 

EFI parts sometimes are not cheap and plentiful, if that is the case, you can build a reliable carb'd turbo that won't blow up, many of have done it, they are forums other than this of owners of cars that haven't blown up, go talk to them if you want MORE proof of reliablity (again as bulletproof as EFI, no, I never said, I never even said EQUAL, but people but some here entirely dismiissed the idea, I'm beginning to think a whole lot full of cars, a convoy, whatever still wouldn't convince you otherwise, but fine) that's all I wanted to say and some of you jumped on me like rabid dogs.

Fine, carburated tubocharged cars blow up at the whiff of psi, they are not driveable, you can't maintain them, they fall apart, they're horrible, if you want to turbocharge a carburated car, you should instead sit on the curb and cry. Attack me, take rep points, do whatever you want, I'm done with this, nobody's listening to anyone else at this point anyways.

I'm an idiot, I'm stupid, I'm blind, I'm whatever adjective you want to put onto me, I tried to have a civil discussion.


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## Zen31ZR (Mar 24, 2004)

You first say it's not better than EFI , but you also insist that it's a worthwhile and troublefree system to build and use. You also insisted that


> The engine will not run poorly or be any more unreliable than any other well-tuned vehicle.


Then you go on to say....


> I'm not saying EFI is worse, it is in fact better, if its feasible in your particular case.



At least you somewhat stick with the idea that EFI is a better choice, but seem a bit wishy washy in other areas as presented with more evidence.....
You claim to have seen many such systems on the internet, and have failed to provide links and data to back your claims. Even somone not really involved in the argument at least posted a couple of links to carbed turbo setups, even though they were one-offs, under developement, or discontinued, or in a specialized application. We asked you to provide evidence of a daily driver carburated turbo setup and all you can throw out is that one of your bosses had such a vehicle. Very well, if it's a fairly well known about car, it should be somewhere on the net. Instead of proving us wrong with data, you attempted to baffle us with bluster, which does not work here. If you have an argument, provide the data related to your side. We would expect no less.


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## BII (May 13, 2004)

[email protected] said:


> You first say it's not better than EFI , but you also insist that it's a worthwhile and troublefree system to build and use. You also insisted that
> Then you go on to say....
> 
> 
> ...



I provided links, books have been written (or a reference is given in books about turbocharging), kits can be bought for air-cooled VWs, but I still can't win or lose. I provide links to other's work, they're discredited as being "something you read on the internet, blah, blah, blah," I don't provide links, "you didn't provide a link." And yes, most systems built today are one-off, because EFI is abundant and its easier (provided sources for EFI components/electronics are readily available to you, sometimes this is not the case, if you don't believe that, ask dbourne, ask some others on this very board), just like more is written about tuning Hondas, you'll find more info on what's more abundant. 

Some Dell'Orto carbs were built for turbo duty, like the Lotus Esprit turbo. A popular progressive carb can also be adapted for turbo use, something like a 32/36 DGV for example. If you say 8-10 PSI is the max using a blowthrough carb setup, what more do you want in a street setup? I'd be grinning ear-to-ear with that, more boost than a supercharger (without the fabrication issues involved with that), and while less than possible with EFI, its still the same or more boost than a lot of off-the-shelf, "street legal" kits for modern 4 cylinders.


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## morepower2 (Apr 19, 2002)

bII said:


> I'm an idiot, I'm stupid, I'm blind, I'm whatever adjective you want to put onto me, I tried to have a civil discussion.


You are not stupid or an idiot but you are stubborn and closed minded. You probably read to many things on the internet. I figure that most owners want something relaible with decent driveabitly and at least more power than they could do NA.

Go ahead and build your turbo, document what it does and prove everyone wrong. If you document your sucess, then you will have something to say and you will be listend to.

Let me ask you have you ever tuned or even driven a car with a carburated turbo? You don't want to heed the advice from people who have? Do your really want to give advice on a subject when you havent tried it yourself?


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## BII (May 13, 2004)

morepower2 said:


> You are not stupid or an idiot but you are stubborn and closed minded. You probably read to many things on the internet. I figure that most owners want something relaible with decent driveabitly and at least more power than they could do NA.
> 
> Go ahead and build your turbo, document what it does and prove everyone wrong. If you document your sucess, then you will have something to say and you will be listend to.
> 
> Let me ask you have you ever tuned or even driven a car with a carburated turbo? You don't want to heed the advice from people who have? Do your really want to give advice on a subject when you havent tried it yourself?


An aircooled VW with a drawthrough setup, a blowthrough with dual DCOEs (one was a school project in HS, the motor was intended for a street car, but went into a drag car instead), a Subaru brat with a blowthrough setup. Aside from that, EFI or carb'd superchargers (a 289 setup with a Kennie Bell, blowthrough and another 289 setup with a paxton centrifugal, drawthrough, and a 350 with dual Holleys and a Weiand roots blower). I helped install, very little fabricating, lots of driving.

Why can a supercharged carburated car be made reliable and a turbo not? It just didn't make sense to me, that's all.


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## morepower2 (Apr 19, 2002)

bII said:


> An aircooled VW with a drawthrough setup, a blowthrough with dual DCOEs (one was a school project in HS, the motor was intended for a street car, but went into a drag car instead), a Subaru brat with a blowthrough setup. Aside from that, EFI or carb'd superchargers (a 289 setup with a Kennie Bell, blowthrough and another 289 setup with a paxton centrifugal, drawthrough, and a 350 with dual Holleys and a Weiand roots blower). I helped install, very little fabricating, lots of driving.
> 
> Why can a supercharged carburated car be made reliable and a turbo not? It just didn't make sense to me, that's all.


DCOE's can tolerate more boost than any other sidedraft because of their ball bearing shafts and double seals. 

Here is my experianced with carbed turbo kits from along time ago. I tried to tune a 280Z with a Jim Cook turbo system with triple DCOE's and it had bowl venting and needle and seat issues after 10-12 psi. Aways ran lean on top. Mikunis could not tolerate any boost at all, numerous bowl and shaft leaks, bend throttle shafts and plates, uncurable. The owner gave up after I tried to jet it numerous times. He didnt want to make a box, it would have been pretty hard for that car due to the ehaxuast manifold. Never did run right, always had driveabilty issues. Detonated and broke ring lands after about 3 months. Owner rebuilt motor and made NA triple sidedraft, was happy and car was faster.

I also worked on a 2.3 liter Pinto with a draw through 3236, the carb worked ok but the turbo sucked oil like crazy, especialy when you closed the throttle, big puffs of smoke with oil pouring out the exhaust and even spit out the carb. It had a big bog and could not get enough pump shot out of it to cure it. It hardly ran when cold. It bucked under off boost and part throttle, jetting helped but could not get rid of all of it and the bog was always there. Tried a holley 600 double pumper with dual reo pumps, still had bog plus mega rich for a few secs due to huge pump shot. Ran ok at WOT but sucked down low, could never get the power valves to work right. Car blew up after about 3 months. This system was a total piece of crap.

510 L16 with crown turbo kit and 3236. Hardly ran any boost, but ran the best of all the carbed turbo kits, hardly made any power and was slower than a stock block L18 with dual sidedrafts and a mild cam. It probalby ran ok because it was a drawtrhoug but everything close to the intake manifold due to the side flow head. Still stumbled and bogged a little and sucked oil from turbo. Didnt blow up, owner totaled the car after a few weeks.

Friend had a BAE turbo first gen RX-7, blew up almost imediatly and ran like crap.

If you could see how stupid these turbos were you would figure they would not run well. All of the companies went out of busness after a short time, Crown, BAE, Cook, I figure because of the bad rap they got. These experiances are why I don't think carbs are viable on turbos.

One of my firends did have a carburated turbo that worked pretty good. It was a RX-7 with twin T25's and twin DGV's draw through. I think it might have been due to the very short path that was all downhill to the engine from the carb. The rotary has the exhaust ports right there and the turbo, carb, intake ports were all close and in line. It ran for a year before blowing up but that was weekends only. It was fast, but not overly reliable.

I think superchargers might work better on V8's because they generaly don't run much boost, they don't need to make much to make good power. Draw through supercharger system don't have the oil ingestion issues and the flow is all short and downhill from the carb so the fuel can't puddle since it still sits on top of the manifold. The short path means less wetted area so the acellerator pump doent need as much shot. I think low boost pressrized carb with referenced regulator will work up to the point of the needle and seat not flowing. Holly are avalible with optional nitrofill floats to prvent them from collapsing. Bigger roots blowers have dual carbs to feed the motor so needle valve flow capacity is not as much of an issue.

I have never built or worked on a carbed supercharged V8 so these are just opinions.


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## Zen31ZR (Mar 24, 2004)

I explained once why a supercharged carburated engine works better a few posts ago, but I guess you missed it. 
A supercharger spins much slower than a turbine, and is much heavier in construction , so it doesn't have the wear issues on a draw-through system. The bearings are heavier with heavier seals and so you won't have leaking issues there. MIkes already said the path from a supercharger to the engine is generally much shorter, and very short on a top-mount blown V8, so thats why supercharged cars work better. 
The centrifugal type superchargers work well on EFI, and would probably about the same as a turbo on a carburated car, IE: would have problems with the accelertor pump shot on a draw through system, pretty much would have to build a box on a blow through system for it to work well.
The only supercharger carburated systems I'm aware of that really have pretty much zero issues are the 4/6/8/10/12-71 Weiand "Roots type" and etc top mount superchargers on the V8 engines. Heavy construction, heavy seals and heavy blades pretty much negate wear issues , even on those cars with twin Mighty Demons on top...... Here's where we get into old familiar territory for me, I did a lot of work on V8s of all types before I turned to tuning imports......


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## BII (May 13, 2004)

[email protected] said:


> I explained once why a supercharged carburated engine works better a few posts ago, but I guess you missed it.
> A supercharger spins much slower than a turbine, and is much heavier in construction , so it doesn't have the wear issues on a draw-through system. The bearings are heavier with heavier seals and so you won't have leaking issues there. MIkes already said the path from a supercharger to the engine is generally much shorter, and very short on a top-mount blown V8, so thats why supercharged cars work better.
> The centrifugal type superchargers work well on EFI, and would probably about the same as a turbo on a carburated car, IE: would have problems with the accelertor pump shot on a draw through system, pretty much would have to build a box on a blow through system for it to work well.
> The only supercharger carburated systems I'm aware of that really have pretty much zero issues are the 4/6/8/10/12-71 Weiand "Roots type" and etc top mount superchargers on the V8 engines. Heavy construction, heavy seals and heavy blades pretty much negate wear issues , even on those cars with twin Mighty Demons on top...... Here's where we get into old familiar territory for me, I did a lot of work on V8s of all types before I turned to tuning imports......


Actually since a roots supercharger does not compress air, it moves it from the intake port to the discharge port, the compression occurs in the intake manifold. In a twin screw the blades don't touch (or at least shouldn't) and don't wear.

The Paxton centrifugal system my dad and I installed on a 289 mustang boosted to 9PSI safely, the carb was sealed and customer still hasn't come back to complain, in fact is very pleased with the results.

The only bolt-on kits I've seen for Japanese cars that are carb'd/turbo are the Janspeed kits (although IIRC HKS and some other Japanese companies marketed versions of blowthrough kits long ago), which I don't think they market anymore. I know they also built them for Mini's and a bunch of other cars. They were very popular, reliable from what I've heard, and he is still in business after 4 decades, albeit he's moved on to other kinds of projects. England did not see catalytic converters as mandatory equipment until the 1990s (from what I'm told by guys in the UK when I visited), so carburation still remained somewhat popular there almost a decade after it pretty much died here.

MacInnes in his book also has many examples of carb'd turbos and describes it somewhat, but as that book was written in 1985, EFI in the US was gaining popularity and I think that's why more of his book is not devoted to discussing carburation and carburattor setup.

And yes, nitrofill or even brass floats have to be installed to prevent crushing them.



morepower2 said:


> also worked on a 2.3 liter Pinto with a draw through 3236, the carb worked ok but the turbo sucked oil like crazy, especialy when you closed the throttle, big puffs of smoke with oil pouring out the exhaust and even spit out the carb. It had a big bog and could not get enough pump shot out of it to cure it. It hardly ran when cold. It bucked under off boost and part throttle, jetting helped but could not get rid of all of it and the bog was always there. Tried a holley 600 double pumper with dual reo pumps, still had bog plus mega rich for a few secs due to huge pump shot. Ran ok at WOT but sucked down low, could never get the power valves to work right. Car blew up after about 3 months. This system was a total piece of crap.


Sounds like he did not have a positive seal on the turbo, I have seen VWs with that condition, and after asking the owner, come to find out that the owner used a turbo from a junkyard, usually off a blowthrough system, thus no positive seal on the turbo (which blowthroughs don't need).


The thinking that a carb and turbo don't mix I think derives from drawthrough systems. There's still muscle cars guys that think turbos "blow up cars," which can happen when you compress gasoline and air.


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## Zen31ZR (Mar 24, 2004)

bII said:


> Actually since a roots supercharger does not compress air, it moves it from the intake port to the discharge port, the compression occurs in the intake manifold. In a twin screw the blades don't touch (or at least shouldn't) and don't wear.
> 
> The Paxton centrifugal system my dad and I installed on a 289 mustang boosted to 9PSI safely, the carb was sealed and customer still hasn't come back to complain, in fact is very pleased with the results.
> 
> ...


 I know people here in town that still make draw-through systems, one guy even has his own manifold design. These are on larger older V8 cars though. I almost had such a system installed on a Firbird I had, an 80 model with a 40 over 400 swap, aluminum heads and Edelbrock low rise intake, headers etc........ At the time I knew nothing about carb/turbo systems, it sounded like a good idea. This was in 1992. The cost kept me from having it done, I think he wanted $3500 , a lot of money to me back then.


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## BII (May 13, 2004)

The appeal of drawthrough turbos is that the fabrication and plumbing is easy, especially on V6/8s and boxer engines. Also, you don't have issues with preping the carb that you do for blowthrough, and tuning is easy, all you have to do is keep enriching to compensate for the extra air and you're to good. Morepower detailed the cons and really the biggest con to drawthrough is that if done incorrectly design or tune the system, you can literally blow the turbo apart and wreak absolute havok under the hood, since you are compressing gasoline and air.

On engines designed pre-catalytic converters, turbocharing at boost levels higher than say ~10 PSI was also dangerous, as these motors have higher compression rates than cars running on unleaded gas with catalytic converters. My buddy in high school built a 12 something to 1 air-cooled stroked VW and was running a water injection system (another throwback, a co-worker who drives a hatchi-roku and is well versed in many a thing auto sport had never heard of such a thing and said I was lying)as a safeguard against detonation. This maybe another reason why many believe carbs + turbo don't mix.

I was once told by a former nieghbor and 240Z owner that as Americans were discovering drawthrough turbocharging and installing them on their cars, the Japanese were already building much better drawthrough turbos. Typical timeline in automotive performance I guess.

Needless to say that drawthrough is a rather crude way to go, but its easier to do than an EFI conversion (in some cases) or a blowthrough.


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## velardejose (Sep 9, 2004)

Hi
Found this thread and thought to post an update
My turbo carbed car went through a couple carbs and ended with a vertical dual throat solex made in argentina
Interesting carb, can be configured for simultaneous or progressive throat opening, removable venturis, emulsion tubes, usw
After a few trials I ended using one throat to get proper vac signal to get enough fuel
Jetting, was a whole story
Idle circuit/jet is stock (55 I think) and allows some gas mileage if driven under 2k (no boost)
Fuel is 150 and air is 120
Car is a daily driver, and after a couple hg issues (lean a/f ratio) at the beginning it runs strong and reliable
I run 4 or 7 psi boost, using 90 oct gas 
It looses traction in 2nd whenever I push my right foot...
Pulls strong til 5k, enough for my goals
Now I am ready to lower my cr to 7.3:1 to run 10 or maybe 14 psi
I learned a lot with this project (and am still learning)
Thanks for all your input


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## 79TA461WS6KY (Mar 3, 2007)

to wake up a dead thread, morepower2 is a complete moron/asshole. Sorry guys, but I've assisted in building and built many custom turbo kits for pontiacs. I can give u the name of a guy right now that has a successful twin turbo CARBED t/a. Runs 9's and he drives it home. Many other names if anyone is interested.


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## morepower2 (Apr 19, 2002)

What did I write that is not true? Sure a low boost carbed turbo on a big displacment motor can go fast. A properly done turbo system is much faster. No high boostreally high powered turbo cars are carburated.


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## 79TA461WS6KY (Mar 3, 2007)

yeah this is true. sorry for sayin that it just seemed like u were really bashing the idea of a carb turbo. while ive never seen any amazingly high boost carbed cars running with high boost, you can still most certainly make decent power with a carb. and i always hate to drop this card, but a carb is simply the best air to fuel ratio meter because thats precisely what it does. the only issue is that it cannot adapt to different environments i.e. elevation, coldness. i believe in carb turbo setups, but i do agree that it is much better to utilize an efi/dfi system for total controll over the turbo and fuel delivery to make sure its there when needed. and on a side note, draw through doesnt seem to be out performing the current blow through setups :-D


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## dburone (Apr 2, 2004)

Let me tell you my opinion on this. I even think I wrote somewhere on this thread.
A couple of years ago after asking everyone on this forum and against popular opinion, i built my custom turbo carb setup on my sentras E16s.
It was very fun and very fast, but tuning was a pain, I tried 3 or 4 carbs until I found one that was from a turbo car, Renault 18 Turbo, and since it was made for a turbo engine it had 3 valves that opened with pressure an let mor fuel in the intake.
But you never get it perfectly running, or the mixutre is too rich or to poor, always something is wrong.
Finally I got myself a japanese sentra with the ga16de and right now im instaling a StandAlone ecu for my turbo project and I really thing that tuning will be a lot easier now!!


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## velardejose (Sep 9, 2004)

Hi
I still run the turboed e16 engine
14 psi daily driver
Its fast, no problems
Found this site, seems they managed to tune turbocarbed stetups with wide band O2 sensors
Carburetor + Boost Tech Questions
Peace


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## morepower2 (Apr 19, 2002)

79TA461WS6KY said:


> yeah this is true. sorry for sayin that it just seemed like u were really bashing the idea of a carb turbo. while ive never seen any amazingly high boost carbed cars running with high boost, you can still most certainly make decent power with a carb. and i always hate to drop this card, but a carb is simply the best air to fuel ratio meter because thats precisely what it does. the only issue is that it cannot adapt to different environments i.e. elevation, coldness. i believe in carb turbo setups, but i do agree that it is much better to utilize an efi/dfi system for total controll over the turbo and fuel delivery to make sure its there when needed. and on a side note, draw through doesnt seem to be out performing the current blow through setups :-D


EFI will put out way more power and driveabilty with way greater reliabilty on a turbo motor that any carbed motor any time.


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## velardejose (Sep 9, 2004)

Hi
Interesting
Way more power? I have no experience there, so I can't speak
More reliable? Like a carbed setup
EFI driveability? Depends on the programmer
For our low budget/far from civilized world setups it is easier to switch between 1 usd jets than paying 100+ usd for each map when upgrading or trying a new mod
It is clear to me efi can get better results in less time, as long as there is enough cash and hardware available
Peace


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## morepower2 (Apr 19, 2002)

velardejose said:


> Hi
> Interesting
> Way more power? I have no experience there, so I can't speak
> More reliable? Like a carbed setup
> ...


To preach that carbed turbos are a relaible alternative is false economy. I is doable but the results are much inferior. Try running a carbed turbo motor for more than one bar at more than just a burst of speed and you can find out just how diffcult and yes expensive it can be in engine damage.


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## velardejose (Sep 9, 2004)

I know, learnt it the hard way...
I am aware of (turbo) carbed configs limitations
Thanks for answering
Jose


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## plouche (Apr 25, 2006)

Mr. Kojima

I have read allot on this matter and found out this

- needle and seat problems :use a rising rate fuel regulator
- lean on top: this is almost a topic by its self. You can use a hobbs switch set at lets say 10psi in the intake and connect it to a valve that gives more fuel in the intake this is mostly done with a injector. 
- shaftleaks : create a pressure barrier with pressure from above the venturi so the mixture stays in.
-Your pinto problem: draw through isnt that good to start of with but if your going to do that you need a positive seal turbo diesels have these.

I'm not a car wiz like you but I think these solutions do make it possible to turbo a carbed car and still make it to be pretty reliable and faster than stock. 

Most people that would build these kind of set-ups on Daily drivers don't want all out power there just looking for a weekend project and some fun on a very low budget.

Greets


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## velardejose (Sep 9, 2004)

Hi
I read the same stuff a couple years ago
Til I started the project, then the hard reality showed what works and what not
What mr Kojima says is that an efi+turbo car is more reliable and has more power than a similar carbed+turbo config under boost conditions
Under (high) boost the tuning line is thinner, and the carbed version needs a bigger safety cushion
It means engine tuning cant be as exact as with efi, and that means less power
With my config I know I have way more power/torque than the average e16 engine, but I also know I would get more power/torque with an efi system running the same boost
This is kind of a personal achievement, and took lots of daily driving
Can be done? Yes
Is carbed superior to efi? With or w/o boost answer is no
Peace


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## morepower2 (Apr 19, 2002)

plouche said:


> Mr. Kojima
> 
> I have read allot on this matter and found out this
> 
> ...


You can't use a rising rate regulator effectivly because most needle and seat valves don't like much more than 7-8 psi of fuel pressure.

The best way to blow through is to pressurise the entire carb or enrichment circuits of the carb, like gale banks did for his camaro turbo kit. That is diffcult and it still doesnt work all that great, for higher boost levels.

Can it be done, yes. Can you always get more power, driveabilty and safety with EFI, yes.


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## Gibson1976 (Apr 18, 2007)

*DUDE!!*



dburone said:


> I´m sure that mpfi is better, but not sure that its easier, you guys have to understand we have different realities, and there are places where carburated is better. A carb is easier to fix and lot cheaper.
> My setup is starting to work out very well and its a e16s turbo with carb.
> I had a chevy 350 efi, and after it stopped working here there wasnt anybody who could fix it, so it went carbed and it never stopped working.
> Sorry, but a carb is better sometimes!!!



I am getting into this whole turbo thing, I my self am an old car freak, but I recently got my hands on a 1986 Nissan E16S for $150. I am wanting to turbo it, not to much, but to make it the only grocery getta with a turbo in my home town. Were can I get my hands on a Turbo manifold for a reasonable price??


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## velardejose (Sep 9, 2004)

hi
Lots of e15et engines data here:
:: Index
Peace


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## dburone (Apr 2, 2004)

Im looking for a manifold for a ga16de and cant find reasonable prices...


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## velardejose (Sep 9, 2004)

Any muffler/exhaust shops in your area?
In my country handwork is very cheap...
Keep us posted
Jose


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## ZombieX (Feb 10, 2010)

*i have a simple solution*

ok you can put an e15et in your car and it bolts right to your trans and it is built to take the turbo pressure (thicker walls in the head and block hence the 1.5 displacement) or go with side drafts. there's a guy on this forum who races rally and ice in a b11 against wrxs, and beats them down with his e16 n/a (how bad ass is that) so i know what this engine is capable of. also i found this engine likes to run retarded rather than advanced (kinda odd but true) i have a hi comp e16. you can put a ca16et out of the the pulsar but you need the trans, or an sr20 but i keep hearing its a bitch and would avoid it if you can. too many variable with the carbed turbo (i know i have a 79 Buick t type), cars that had those setups typically have compressor impellers with special coating on them to protect the blades and then you have to think about air density and barometric pressure not to mention a/f ration and climate change. i like the simplicity of the carbed setup but for practicality its going to cost you more in the long run. you need to also remember a turbo car need twice as much maintainence, oil gets burned up faster so do plugs.so weigh out the pros and cons, i dont know everything but i do my research on this stuff before i do it.


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## ZombieX (Feb 10, 2010)

check venus-auto in sacramento ca i think ronald can still get the e15et or can find them


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## dburone (Apr 2, 2004)

2 years later I changed my car and now I have a turbo GA16de making 200+ hp and I love it!
Later ill post more info about the project.


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