Calculatin Max boost
04-02-2007, 12:02 PM
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Calculatin Max boost
I have a Speedforce Stage 1 turbo (T04b) I believe how do I know how much boost to plan for?
Is there a calculation involved? Or is it all trial and error. Currently the injectors are stock but that might change. How do you know when you are out of the efficiency range of the turbo?
Is there a calculation involved? Or is it all trial and error. Currently the injectors are stock but that might change. How do you know when you are out of the efficiency range of the turbo?
04-02-2007, 12:27 PM
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Its a matter of how your fuel and ignition maps are setup. This most likely means what chips you have.. Unless you have a piggyback computer of some kind for tuning. Also, I've heard that stock injectors max out around 18psi with the stock turbo..
What chips do you have? Your signature says StageII APE.. what boost are they designed for?
What chips do you have? Your signature says StageII APE.. what boost are they designed for?
04-02-2007, 12:33 PM
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Bigger injectors, chips, PB etc. can help stretch the eff. range of a turbo, but your best bet is to get a turbo that is in the range of your performance needs from the get go.
04-02-2007, 02:13 PM
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Currently the car has stock injectors and APEII chips with a MAF and Split Second fuel computer.
But I am planning a project and want to make sure that I have made good decisions.
Right now I am leaning towards stand alone and later engine work. But I want the car to be the complete package.
The turbo is relatively small although bigger then a K26.
In the end I want everything to be sized to match what the turbo can do.
But I am planning a project and want to make sure that I have made good decisions.
Right now I am leaning towards stand alone and later engine work. But I want the car to be the complete package.
The turbo is relatively small although bigger then a K26.
In the end I want everything to be sized to match what the turbo can do.
04-02-2007, 04:14 PM
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well if you want to keep stock injectors then with a 3.0 bar FPR I was able to spike to 20psi w/o problems (fuel wise) but would get lean above 15psi at redline. 20psi was seen around 3200 rpm. so a stead decline from about 4300rpms (20 psi) to 15psi at redline was fine. any boost under that curve should be supported by the stock injectors.
that was my observation with MY car. other people may have other opinions and experiences.
that was my observation with MY car. other people may have other opinions and experiences.
04-03-2007, 12:48 AM
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Kool,
the answer to your question is this:
Find out what cfm your current turbo is capable of flowing.
Rough guideline: 500 cfm will have enough capacity to provide for 350 (maybe 375) crank hp, at sea level.
Chances are that your injectors will then be the weekest link.
Bigger injectors will then require remapping.
the answer to your question is this:
Find out what cfm your current turbo is capable of flowing.
Rough guideline: 500 cfm will have enough capacity to provide for 350 (maybe 375) crank hp, at sea level.
Chances are that your injectors will then be the weekest link.
Bigger injectors will then require remapping.
