# DIY turbo questions



## Guest (Jan 22, 2003)

ok i have been planning a DIY (do it yourself) turbo project lately.
i figure i can piece everything together. i am doin ggood so far.. still planning everything out... i'm looking at about $850 so far. but i think the ecu will put me over my $1000 budget. i was thinking if this might work, and i kinda borrowed the idea off of one of my genious friends, but if i dont upgrade my ecu, and run a bigger MAF (such as a 95 or 96 240sx) and bigger injectors (such as 370cc 300zx injectors) i already have both of those as left over parts from previouos 240sx projects. does anyone already have a lay out of everyhting planned for a turbo install. 
pm me if you have anything to sell. thanx


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## James (Apr 29, 2002)

if you don't upgrade your ecu you won't be able to run the larger maf or the injectors without buying other more expensive pieces...


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## bahearn (Jul 15, 2002)

Come on, DOPE, do some research. Hit that search button and start plumbing the depths of already-existing information.


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## Guest (Jan 22, 2003)

the whole point of this is affordablility i'm trying to keep my project under $1k. the ecu alone is half that price. can anyone give me a better estimate on the price of a JWT tuned ecu. this concept really does make sense. my friend and i have tried it on his 240 KA24de-turbo... still in the works.. pushing 9psi now with no ecu. we used 300zx MAF with 560ccinjectors. the MAf should confuse the ecu, run the proper amount of air to fuel to match the MAF so the KA24 240sx MAf is a perfect fit and should work. i was just wondering if anyoen else may have done it.. thanx for any input
also if anyone is selling anything pertaining to my turbo project hit me up


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## mpg9999 (Nov 22, 2002)

I believe a jwt ecu will run you around 500-600. Personally, I dont know if Id run a larger Maf with larger injectors to compensate for each other without first doing alot of math to figure out how well its gona work. you could also run an apexi afc or something like that, although thats not as good as a jwt ecu, its probably better then what your planning.


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## James (Apr 29, 2002)

DOPE200sxSE said:


> *the whole point of this is affordablility i'm trying to keep my project under $1k. the ecu alone is half that price. can anyone give me a better estimate on the price of a JWT tuned ecu. this concept really does make sense. my friend and i have tried it on his 240 KA24de-turbo... still in the works.. pushing 9psi now with no ecu. we used 300zx MAF with 560ccinjectors. the MAf should confuse the ecu, run the proper amount of air to fuel to match the MAF so the KA24 240sx MAf is a perfect fit and should work. i was just wondering if anyoen else may have done it.. thanx for any input
> also if anyone is selling anything pertaining to my turbo project hit me up *


you're not going to get it under 1k... with or without the JWT ecu you're going to spend an ass load of money. I have everything you have plus the manifold plus a t28 b/b turbo, a spare ecu w/ the JWT stage 2 program, the HS piping and it came up to about 2200... and that is good!


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## hagasan (Aug 5, 2002)

^^^^^^^^^^^What he said^^^^^^^^^^^^^^


Hell $2200 seems like a bargain. When i was pricing mine I could NEVER come under $3000.


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## Guest (Jan 23, 2003)

wow well alot of my stuff is custom fab, or used.. so trust me i did it for my old 240.. i'll pull it off. and btwi left out th part of the air bypass after the maf. my concept allows air to flow through the maf as well as aroudn it so i'm getting enough air to support the fuels system and actually make it run a bit lean , rather than way rich.. you'll see


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## wes (Apr 30, 2002)

*MAF*

I don't see how you will be able to make a bypass for the MAF without making the car run like crap. The ECU reads voltages from the MAF to adjust the AF ratio accordingly. I think it would have to be a VERY complex system to let the right amount of air in just to lean it out a little. If you were set on that why don;t you buy and adjustable FPR or an APEXi unit to accomplish this?


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## CarloSR (Nov 29, 2002)

James said:


> *if you don't upgrade your ecu you won't be able to run the larger maf or the injectors without buying other more expensive pieces... *


The ECU controls everything. It will run like shit.


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## sentravis (Jul 7, 2002)

thats a sweet ass looking car carloSR!!!!! very classy looking.. almost saab or bmw like.. nice..


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## CarloSR (Nov 29, 2002)

Thanks 1999GXE1.6..


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## NissanTuner (Dec 1, 2002)

to test this theory unplug the sensor cable from your MAF and rev the engine, youll see how your car runs, and throw a service engine soon light.


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## mpg9999 (Nov 22, 2002)

You guys dont understand whats he's doing. Read it again. Im not saying its gona work. But non the less, I believe you guys arnt understanding what he's saying.


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## James (Apr 29, 2002)

doesn't matter, if you're running more air around the MAF, the engine will run like crap and is very dangerous unless you add in an extra injector that is pumping fuel in all the time...


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## mpg9999 (Nov 22, 2002)

Bigger MAF= run lean
Bigger injectors= run rich
Bigger MAF+Bigger injectors=just right, or so his theory goes.

I dont think it will work, but thats basically what he is saying.


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## blairellis (Jul 6, 2002)

HOLY MORON BATMAN!


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## James (Apr 29, 2002)

DOPE200sxSE said:


> *and btwi left out th part of the air bypass after the maf. my concept allows air to flow through the maf as well as aroudn it so i'm getting enough air to support the fuels system and actually make it run a bit lean , rather than way rich.. you'll see *


I think he meant he's going to get a pipe that runs air around the maf from another filter... which still doesn't make it work. He didn't say anything about bigger MAF or bigger injector. if you add in more unaccountable air then it will run lean no matter what size the MAF... you have to start dumping in fuel and it'd be very hard to balance out even with bigger injectors.


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## mpg9999 (Nov 22, 2002)

Read the very first post, thats where he said he will run bigger injectors.


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## James (Apr 29, 2002)

what the hell does the first post have to do with it? of course you have to run bigger injectors when you boost? I'm talking about his MAF idea...


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## mpg9999 (Nov 22, 2002)

Alright buddy, your still not getting it. Please read his first post again.


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## mpg9999 (Nov 22, 2002)

Here, lemme help you. 
"i was thinking if this might work, and i kinda borrowed the idea off of one of my genious friends, but if i dont upgrade my ecu, and run a bigger MAF (such as a 95 or 96 240sx) and bigger injectors (such as 370cc 300zx injectors)"

He said he wants to run both a bigger maf, and bigger injectors.
now, let me say this again:
Bigger MAF= run lean
Bigger injectors= run rich
Bigger MAF+Bigger injectors=just right, or so his theory goes.


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## James (Apr 29, 2002)

mpg9999 said:


> *Alright buddy, your still not getting it. Please read his first post again. *


Ok what is YOUR point? I see in his first post he is adding in bigger injectors and bigger MAF... ok he can do that? so what that's obvious! without the ecu he still would run like crap and with that stupid air bypass he'd run like crap so unless you're suggesting something else that I must be OBVIOUSLY missing, please speak up.


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## CarloSR (Nov 29, 2002)

It will still run like shit. Need ECU upgrade to handle the "Bigger MAF+Bigger injectors"...............Or else I see a blown engine.
Period.


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## James (Apr 29, 2002)

mpg9999 said:


> *Here, lemme help you.
> "i was thinking if this might work, and i kinda borrowed the idea off of one of my genious friends, but if i dont upgrade my ecu, and run a bigger MAF (such as a 95 or 96 240sx) and bigger injectors (such as 370cc 300zx injectors)"
> 
> He said he wants to run both a bigger maf, and bigger injectors.
> ...


still doesn't work, sorry, you can't just add two big things together and not change the ecu that controls them and expect them to balance out.


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## mpg9999 (Nov 22, 2002)

Yes, I know it probably wont work. I doubt very much that they will be able to balance each other out. My point was that you guys werent understanding exactly what he was saying.


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## James (Apr 29, 2002)

no i understand exactly what he's saying, I don't understand what you're saying.


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## mpg9999 (Nov 22, 2002)

All I was saying is that you guys didnt understand what he was saying.


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## James (Apr 29, 2002)

damnit this is stupid... wtf do you mean I'm not understanding? can somebody explain to me what I'm missing here?


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## mpg9999 (Nov 22, 2002)

didnt. past tense. I see that you understand what he was saying now. And theoretically his idea works, although I dont see how he is going to be able to match up the injectors and MAF.


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## James (Apr 29, 2002)

mpg9999 said:


> *didnt. past tense. I see that you understand what he was saying now. And theoretically his idea works, although I dont see how he is going to be able to match up the injectors and MAF. *


no theoretically his idea doesn't work, that's what I'm saying, maybe in a world without ECU's but then there'd be no MAF's woudl there? 

what does match up the injectors and maf mean?


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## mpg9999 (Nov 22, 2002)

Ok. Let me try to explain this. The ecu sends an electronic signal, or injector pulse width, to the injector which will determine how long it stays open, which, among other things, determines how much fuel will flow into the cylinder. One of the main things that determine injector pulse width is the MAF voltage. If he upgrades to a larger MAF, more air will flow in then the ecu "see's", so it would run lean. However, if he ran larger injectors in conjuction with the larger MAF, the injector pulse width would remain the same, but more fuel would flow threw them since they are larger, theoretically offseting the extra air from a larger MAF. The problem is finding a MAF/Injector combination that will compliment each other. Please, correct me if im wronge, it wouldnt be the first time.


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## James (Apr 29, 2002)

mpg9999 said:


> *Ok. Let me try to explain this. The ecu sends an electronic signal, or injector pulse width, to the injector which will determine how long it stays open, which, among other things, determines how much fuel will flow into the cylinder. One of the main things that determine injector pulse width is the MAF voltage. If he upgrades to a larger MAF, more air will flow in then the ecu "see's", so it would run lean. However, if he ran larger injectors in conjuction with the larger MAF, the injector pulse width would remain the same, but more fuel would flow threw them since they are larger, theoretically offseting the extra air from a larger MAF. The problem is finding a MAF/Injector combination that will compliment each other. Please, correct me if im wronge, it wouldnt be the first time. *


ok let me explain this, the MAF is an electrical device, it measures electrical signals, when you upgrade it it does not recognize these new signals. in order for that to happen you need an ecu upgrade... same goes for the injectors, they will not open properly without the ecu being reprogrammed!!! you cannot just plug things in and expect things to work the same! do you understand?


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## mpg9999 (Nov 22, 2002)

Why wouldnt the Injectors still open up (as long as you use the proper impedence and side feed) if you went to a larger one without upgradeing the ecu? IM me on aol. My sn is mpg9999


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## James (Apr 29, 2002)

The pulse width is not constant with every injector, you're not going to get more fuel just by plugging in a larger injector. Same as the MAF.

The injectors would still open up, but for the wrong length of time delivering the wrong amount of fuel so it'd run like crap... like I said before, it won't work unless you like a rough ride.


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## mpg9999 (Nov 22, 2002)

Im pretty sure your wronge. If you went and replaced the stock sr20 injectors with 370 cc's from a Q45, you would run rich. Again, I could be wronge, but im pretty sure thats true. And are you gona IM me? thanks.


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## James (Apr 29, 2002)

I know you're not trying to be hostile, but the point is made and you keep wanting to know why? Well I don't have the math to prove in every situation you're wrong but the old saying goes that even a broken clock is right twice a day right? Same goes for what you're suggesting, I'm sure at a certain rpm it will produce the proper ratio in fuel and air and it will be great but what the hell is the point in that?


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## mpg9999 (Nov 22, 2002)

Alright. Well im am niether convinced nor dissuaded that it wont work throughout the rpm range. When I see evidence (that obviously niether of use have) then I will be convinced. I will try to do some research on this.


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## James (Apr 29, 2002)

I don't understand why you think this would work just as well as an ecu upgrade... why did they even come up with ecu upgrades then? Why isn't everyone doing this if it's just as easy as compensating larger injectors with a larger maf? Wow so simple right? 

It will turn on and it will run but it will not develop nearly as much power as with an ecu upgrade and it will run rough because the air fuel ratio will never be right except for your one rpm where it might cross the threshold.


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## Ericdd (May 14, 2002)

James said:


> * why did they even come up with ecu upgrades then? Why isn't everyone doing this if it's just as easy as compensating larger injectors with a larger maf? Wow so simple right?
> *


Maybe no one does this because no has tried it. If you haven't ried it or know some one who tried it then you cannot say it can't be done, you can only say you don't THINK it can be done. 

What do you think JWT will tell you you don't need their ECU if you just use these injector and this MAF? Who would give them a dollar after that? 

There was a whole thread about ECU tuning and after reading that I believe it's possible. I could'nt figure out the math but why couldn't it be done. When you switch a MAF or injectors they just change the FUEL map to compensate they don't re-invent the wheel. The O2 sensor will also help the computer reprogam itself.

Theoretically I believe it's possible, BUT I believe JWT is the only one that will be able to figure the combination and they will never tell. 
Read this and you will see it can be done


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## James (Apr 29, 2002)

James said:


> *I don't understand why you think this would work just as well as an ecu upgrade... why did they even come up with ecu upgrades then? Why isn't everyone doing this if it's just as easy as compensating larger injectors with a larger maf? Wow so simple right?
> 
> It will turn on and it will run but it will not develop nearly as much power as with an ecu upgrade and it will run rough because the air fuel ratio will never be right except for your one rpm where it might cross the threshold. *


What isn't possible? I said it will run and turn on didn't I???


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## mpg9999 (Nov 22, 2002)

I dont think this will work as well as an ECU upgrade. An ECU upgrade would definatly be the best thing. But, I think this still might work, and not just at a specific rpm like your saying.


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## mpg9999 (Nov 22, 2002)

I asked the people at www.sr20deforum.com, here is the thread: http://www.sr20deforum.com/showthread.php?s=&postid=282302#post282302 Here is some info that one of them gave on how to upgrade you injectors without upgrading the ecu: http://www.autospeed.com.au/A_0008/P_1/article.html


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## Ericdd (May 14, 2002)

so what does that mean. I always wanted a car that turned on, maybe next year I'll have one.

after it turns on then the ECU will begin to compensate and soon it will learn to work, maybe not 100%, but it will learn. but you don't care any way so whatever.


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## James (Apr 29, 2002)

yeah that's exactly what I said...


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## javierb14 (Jul 9, 2002)

but wait, the 240's didnt come with 370cc's with their MAF's....how does it cancel out? i have yet to see any calculations or sensible theories stating that it works. 

if u really want to try it go ahead! do you have a wideband 02 sensor? how will u tell how well it works? 

if u really want to try a different route then JWT, then try the mega squirt DIY fuel comp, its real cheap.....but u have to solder it together
http://www.bgsoflex.com/megasquirt.html
but then u still need a black box for ignition.

IMO save ur $ and go with the JWT. its so easy, just plug and play...*and it works GREAT* in the end, the JWT ecu will cost less and is easier to install than a new engine into ur car.


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## mpg9999 (Nov 22, 2002)

javierb14 said:


> *but wait, the 240's didnt come with 370cc's with their MAF's....how does it cancel out? i have yet to see any calculations or sensible theories stating that it works.
> 
> if u really want to try it go ahead! do you have a wideband 02 sensor? how will u tell how well it works?
> 
> ...


I have no idea what it would work with. I just think that if you could match up the Injectors and MAF it might work out.


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## James (Apr 29, 2002)

I can't believe you're still on this even after that reply you got from the other forum.... there's your data, not that you needed that in the first place.


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## James (Apr 29, 2002)

javierb14 said:


> *but wait, the 240's didnt come with 370cc's with their MAF's....how does it cancel out? i have yet to see any calculations or sensible theories stating that it works.
> 
> if u really want to try it go ahead! do you have a wideband 02 sensor? how will u tell how well it works?
> 
> ...


javier, if you go to sr20deforum.com you can find his thread where someone has data to prove that it does not work...


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## mpg9999 (Nov 22, 2002)

I do not think it will work.


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