# is it doable??



## Marty01 (Dec 20, 2004)

i was wondering.. to build a system that you can tune the boost as your driving.. i would need;

Electronic boost controler.. fromt he drivers seat.. run whatever boost i can within reason of course..

fuel preasure regulator.. ive heard of some that are boost seneitive.. so more boost more fuel goes in..

what abotu the spark though?? more boost means more retard on the timming right?? how would one go abouts doing this.. im hoping to figure out a way to do this boost sensitive as welll.. or am i thinking bad that way??


im hoping to have the end result to be able to turn down the boost to say.. 4 or 5 psi.. for fuel savings.. than be able to crank it up to 15psi for play time.. and still be able to run anythign in between as well.. how much trouble do you guys think this would be?? any other areas i should tackle??

thanks


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## nismo200sx16 (Aug 25, 2004)

I think what your looking for is a 2 stage boost controller. its cheap and you can run your sr's factory boost of 7psi and at a flick of a switch you can run 13 or 14 psi. I wouldn't run any more than that on a stock sr with stock turbo. the turbo is vary un efficient any higher and will were out quickly. and any boost higher than about 10psi you should think about a better headgasket.
the sr headgasket is not that great it might hold up to 14psi but it could develop a leak. as for fuel you should have a high flow just to run a stock sr. a warboro fuel pump is a cheap and eficitive choice and will support up to about 400 hp.the stock sr fuel system will be fine for 14 psi and the stock ignition should be fine to. if you want more adjustability in boost you could get the apexi unit its awesome, and their fuel controller can be connected to the boost controller and it will up fuel with boost. but that is not need to run 14psi. if you want to run more than that you need a new turbo a headgasket maybe injectors and on any turbo car you should always have a air/fuel gauge to keep an eye on every thing.


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## Marty01 (Dec 20, 2004)

nismo200sx16 said:


> I think what your looking for is a 2 stage boost controller. its cheap and you can run your sr's factory boost of 7psi and at a flick of a switch you can run 13 or 14 psi. if you want more adjustability in boost you could get the apexi unit its awesome, and their fuel controller can be connected to the boost controller and it will up fuel with boost. but that is not need to run 14psi.


the ignition itself most likely has enough sopak in it.. im wonering about timing wise.. changing boost on the fly does mean either setting timing so it wont knock whithin the range of boost.. (which to my understanding will rob you of either power under high boost.. or fuel efficiency under lower boost)

and im not looking for this or that boost level.. im looking to be able to go from say 5psi by one psi increments up to 15psi.. so a 2stage WONT work..

as far as other internal engine/turbo changes to make this range a possibility.. im not conserned with that.. only with being able to select the boost i wanna run from the drivers seat.. adn let the car "adjust" itself to maximize whatever setting im at..

so back to my question.. hhow would one make the timing of the ignition boost sensitive?? as to get max efficiency/power from such a wide range of boost (for lack of better term)?

the reason im asking is i dont want to run 15psi all the time.. as i really dont want to deal with that much go for daily driving to/from work.. but i do want to be able to get that much power when its called for.. and i figure by backing the boost to a level slightly lower than stock (hence the 4 or 5 psi) with diferent mods.. i should be makign the same power as stock but with les boost.. if that sounds right.. pipping effeciency might not give me 2psi but whatever.. you get the idea


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## nismo200sx16 (Aug 25, 2004)

try the "MSD boost timing retard" thats what your looking for. but not sure if it will work on the sr. the sr ecu will automatically retard the timing if any knock is detected. as for the boost controller any electronic boost controller can do what you want, but I highly recommend the apexi unit. you can adjust the boost to any psi at any select rpm in each gear seperatly. and you can change it all quickly when driving. if you run less boost the engine will not run as efficient and you will not save any gas. the sr is not a fuel hog unless you ask it to be.


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## nismo200sx16 (Aug 25, 2004)

sorry I checked on the msd unit and its only for cars with distributers. not sure but I think the ecu will retard timing automatically. If you get a power fc or some other standalone that could do any thing you want with timing and fuel. but they can get pricy. but I have seen the power fc on ebay go for like $600.


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## lshadoff (Nov 26, 2002)

Marty01 said:


> so back to my question.. hhow would one make the timing of the ignition boost sensitive?? as to get max efficiency/power from such a wide range of boost (for lack of better term)?


The JWT ECU modification (or several stand-alone engine management systems) handles all of that. It has an ignition map for all boost levels which is self-learning. You don't have to worry about any air/fuel or ignition timing at any boost level. All JWT has to know is the injectors, MAF, and cams you are using. 

There are programmable electronic boost controllers which can, for example, change the boost with rpm (or any other inputs). 

With those two, you can do anything imaginable with the boost. 

Lew


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## Marty01 (Dec 20, 2004)

lshadoff said:


> The JWT ECU modification (or several stand-alone engine management systems) handles all of that. It has an ignition map for all boost levels which is self-learning. You don't have to worry about any air/fuel or ignition timing at any boost level. All JWT has to know is the injectors, MAF, and cams you are using.
> 
> Lew


cool.. so the JWT ECU will also be able to dump in more/less fuel based on the needs of which ever boost im running whenever i change the boost on the fly?

also.. anyone know what happens when running bigger injectors for when dialing up the boost... what happens when you turn the boost down.. do you still get all that extra fuel causing a rich condition? or do the injectors simply dont fire for as long keeping air/fuel ratios decent and saving fuel?

the idea here is to run very low boost (4 maybe 5 psi) and be able to get roughly 22 to 28mpg daily driving.. or turn the boost up for the strips/track/street lights/etc and to heck with fuel savings hehe the goal for the higher boost is 300WHP to its a tall order im hoping to fill in


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## lshadoff (Nov 26, 2002)

Marty01 said:


> cool.. so the JWT ECU will also be able to dump in more/less fuel based on the needs of which ever boost im running whenever i change the boost on the fly?
> 
> also.. anyone know what happens when running bigger injectors for when dialing up the boost... what happens when you turn the boost down.. do you still get all that extra fuel causing a rich condition? or do the injectors simply dont fire for as long keeping air/fuel ratios decent and saving fuel?
> 
> the idea here is to run very low boost (4 maybe 5 psi) and be able to get roughly 22 to 28mpg daily driving.. or turn the boost up for the strips/track/street lights/etc and to heck with fuel savings hehe the goal for the higher boost is 300WHP to its a tall order im hoping to fill in


 If you put in higher flow injectors, the JWT ECU needs to be reprogrammed ($100). Once this is done, the engine runs at near optimum A/F ratio and spark advance for all conditions. 

I have a Profec B boost controller set for 6.5# and 9#. (The wastegatge is set for 4.5#.) I can be accelerating at 6# and switch to 9# without any problems. I use this because the front tires will break away in 1-st gear at 9#. So I use 6.5# through 1-st and switch to 9# after I shift. 

I get 30-32mpg on the highway at 65mph. It doesn't matter what the boost is set to when cruising because you are not boosting then. 

You really should read up on the basic operation of modern engine management systems. You are worried about things which are not a problem. 

Lew


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## Marty01 (Dec 20, 2004)

lshadoff said:


> You really should read up on the basic operation of modern engine management systems. You are worried about things which are not a problem.
> 
> Lew


 noo kidding! lol im just not the type of person who likes reading up on electronics.. unless its stereos! lol


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## lshadoff (Nov 26, 2002)

Marty01 said:


> noo kidding! lol im just not the type of person who likes reading up on electronics.. unless its stereos! lol


I think you should get someone else to build your car. If you don't understand what you are doing, you are bound tomake mistakes.

Lew


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## Marty01 (Dec 20, 2004)

lshadoff said:


> I think you should get someone else to build your car. If you don't understand what you are doing, you are bound tomake mistakes.
> 
> Lew


wow.. those are harsh words my friend... im researching everything before any wrenching is done.. i know what i want to acheive.. just figuring out all the lose ends before this is tackled just so i dont screw anything up.. turbo's is something relatively new to me.. my specialty resides in suspension... that aspect is already dealt with.. what i need now is more go power... which im trying to peice together something that wil perform like i want it too.. what ive done so far is check out my friend's rides and see the good and the bad about each f them... and go from there...

btw.. what youve done to me is like me telling someone wanting to learn about suspension that asking too many quetions means they are inadequate to doing this... you learned much like im learning sometimes.. am i right?

true.. im not very well versed in ECU functions and so on.. but i do know what i want to acheive with this engine compartment... i do know what an engine needs to make great power.. or very good efficiency.. i just hapen to want to combine both.. so im cheating by reducing boost to gain efficiency.. end results will be ill have a 300HP car that still gets great millage hehe


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## lshadoff (Nov 26, 2002)

Marty01 said:


> wow.. those are harsh words my friend... im researching everything before any wrenching is done.. i know what i want to acheive.. just figuring out all the lose ends before this is tackled just so i dont screw anything up.. turbo's is something relatively new to me.. my specialty resides in suspension... that aspect is already dealt with.. what i need now is more go power... which im trying to peice together something that wil perform like i want it too.. what ive done so far is check out my friend's rides and see the good and the bad about each f them... and go from there...
> 
> btw.. what youve done to me is like me telling someone wanting to learn about suspension that asking too many quetions means they are inadequate to doing this... you learned much like im learning sometimes.. am i right?
> 
> true.. im not very well versed in ECU functions and so on.. but i do know what i want to acheive with this engine compartment... i do know what an engine needs to make great power.. or very good efficiency.. i just hapen to want to combine both.. so im cheating by reducing boost to gain efficiency.. end results will be ill have a 300HP car that still gets great millage hehe


You told me "im just not the type of person who likes reading up on electronics" when I suggested you "read up on" engine management systems. This is basic knowledge anyone needs to understand how to achieve the goals you stated. You demonstrate your lack of knowledge by stating that it is "cheating by reducing boost to gain efficiency". It doesn't matter what level of boost an engine is capable of when it is just driving down the highway at a constant speed. A knowledge of the engine management system would make this clear.

What you plan to achieve has been done by many others before you. All you have to do is assemble the components to achieve the horsepower goals, and you will have a car that gets good mileage on the highway. Making "great power" AND "good efficiency" is a fundamental property of a turbocharged engine. There's no mystery about it. Just build your 300WHP engine and the rest comes along with it. 

A knowledge of the combustion process and its relation to detonation (the enemy of boost), and engine management systems will give you the skills to choose the components necessary to build a reliable engine. It will also allow you to ask intelligent questions of others who have done this before you.

Don't tell me you won't put in the effort to learn what you need to know, and then chide me for calling you out for it.

Lew


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## Joel (Jun 11, 2003)

Most top of the line boost controllers do this - like the Apexi AVCR. 

Most common use for stages boost is to reduce off the line wheelspin in quarter mile runs. Its a good idea but the system is quite complex since you have to employ the use of a solenoid and some kind of square wave with duration set proportionate to road speed.


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## Marty01 (Dec 20, 2004)

lshadoff said:


> It doesn't matter what level of boost an engine is capable of when it is just driving down the highway at a constant speed.
> 
> A knowledge of the combustion process and its relation to detonation (the enemy of boost), and engine management systems will give you the skills to choose the components necessary to build a reliable engine. It will also allow you to ask intelligent questions of others who have done this before you.
> 
> ...


you see here lies my problem... i do not want 2 settings for boost.. i want to be able to tweak it as i see fit on the lfy.. it be 10pis.. 12pis.. 7psi.. whatever...

i do not think a stand alone ecu setup would work or be nessassary in my case.. i do beleive i can acheive what i set out to do without spending about as much as the mechanical components it would control hence why im asking if there is a different way of doing this and also why i dont wish to read up on after market ecu's and stand alone systems... JWT is a good possibility though.. even if i still beleive i can acheive what i want without resorting to that...

i totally understand that building a turboed engine for high boost means that unless you get rhe revs up to boost.. it wont be any less efficient.. what i want is light boost for everyday driving o i can still get some go when i want some extra.. and dial in lots of extra go for when i really want to go.. all without resorting to 2 or 3 different settings.. hence some sort of boost controler.. eletronic ones will allow me to better taoilor the boost.. whats left for me to do now.. is make sure enough fuel gets to the cylinder and make sure the engine's timing wont let things go sour on me..

why you judged me so quickly i have noo idea.. specially when i didnt find much info i can use or even somewheres to get info from you.. im sure you know how to get the end results im looking for.. and have no doubts you might know more about ecu's then i do.. i just dont want to resort to using a litle black box to control the mechanical parts when something else.. will do just as well.. and cost alot less


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## lshadoff (Nov 26, 2002)

Any simple boost controller will do what you want. They all have a knob that controlls the boost. You will need an electronic one since you need a knob inside the car. If you have a boost gauge, you just watch it and turn the knob while accelerating.

A bit more expensive is a digital boost controller which displays the boost. Just turn the knob and it goes to that boost.

If you do not have an engine management system set up for boost, your engine will destroy itself. The JWT reprogrammed ECU is plug-and-play. Just install it and forget it. However there is one caveat: you cannot turn the boost up beyond what the components (injectors, MAF, fuel pump) can handle, or the engine will go lean and detonate.

You never said what engine you want to turbocharge. Some can handle 300WHP without internal modifications, and others can not.

Lew


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## Marty01 (Dec 20, 2004)

sr20det all the way... im well aware i might need internal peices to make things work.. and that will all be dealt with when the time comes... im more worried about having everything sorted out before anything is done.. figure out how much i would need to spend to make this happen.. then hop to it i guess

i do beleive the bottom end would be stressed to close to the limits and the top end will be modified to make breathing much easier .. turbo, injectors, MAF piping everything will be changes to allow for better breathing to hopefully not need to go as high with the boost to make the power.. that would be the ultimate in my mind


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## lshadoff (Nov 26, 2002)

Marty01 said:


> sr20det all the way... im well aware i might need internal peices to make things work.. and that will all be dealt with when the time comes... im more worried about having everything sorted out before anything is done.. figure out how much i would need to spend to make this happen.. then hop to it i guess
> 
> i do beleive the bottom end would be stressed to close to the limits and the top end will be modified to make breathing much easier .. turbo, injectors, MAF piping everything will be changes to allow for better breathing to hopefully not need to go as high with the boost to make the power.. that would be the ultimate in my mind


The SR20 block is good to 350WHP without modifications. The stock T25 turbo will be hard pressed to make 300WHP. You will need at least a T28. Also you will need a front-mounted intercooler, bigger injectors, a Walbro 255 fuel pump (or equivalent), and a bigger MAF (Mustang, or equivalent).

Lew


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## Marty01 (Dec 20, 2004)

lshadoff said:


> The SR20 block is good to 350WHP without modifications. The stock T25 turbo will be hard pressed to make 300WHP. You will need at least a T28. Also you will need a front-mounted intercooler, bigger injectors, a Walbro 255 fuel pump (or equivalent), and a bigger MAF (Mustang, or equivalent).
> 
> Lew


yuppers.. already taken into account


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## Kouki S14 (Dec 24, 2004)

There are many engine management systems that will allow you to change the boost to whatever you want with the touch of a button. If you want the optimum power at each boost level, you need to find one that will save a few different fuel/timing maps. But if all you want is the control of your boost, Just pic the system that you like the best.


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