Fuel PSI for Type R's Supercharged

[ITR1416]

I'm not quite understanding the meaning or difference between "static psi and idle psi."
Can someone please explain the difference? I'm also curios as to what PSI settings people are running at. My car is currently at 55PSI idle and 80PSI at full boost. Timing is stock 16 degress, I have the JR map controller and BTC installed. Running 5.5 boost. The BTC is about 5 clicks from the left, no pinging at ALL!!

[Batoutahell]

Static fuel pressure is measured by removing the vacuum hose from the fpr when the car is at idle. Ever the sophisticated mechanic, I jam a golf tee in the vacuum hose while I take my measurement.

[austrian type-R]

Those numbers sounds okay since you use the stock injectors and have no AEM FPR to reduce idle FP.

I have RC310 injectors, AEM FPR and Cartech FMU and tuned the a/f mix. with the VAFC.
MY idle FP is about 45psi and my WOT FP is about 55psi.

A high FP is not good for the whole fuel system like pump, rails and injectors. The stock FP is about 40 what I?ve heard. Look, you are running the double of the stock FP. I won`t do this for a long time.



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Supercharged ITR?98 @ 5.5psi
BTC unit, Apexi VAFC, K&N short ram intake, skunk2 cam gears, Kamikaze 2.5", ceramic header, Thermal 3" exhaust, RC 310 injectors, Cartech FMU, AEM FPR
http://www.geocities.com/superchargedtyper
http://albums.photopoint.com/j/Album...622&a=12515817
http://www.geocities.com/autitr/myin...l?991952862150

[Batoutahell]

Before I went with an engine management system, I lowered my static fp to 48-50psi. The fpr would not go any lower. I would have lowered to 45psi if I could. Have you checked your static fp?

[austrian type-R]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by ITR1416:
But I'm still curios to know if I'm in the correct PSI range or if I can lower it for more power? <HR></BLOCKQUOTE>

You will see if you can drop the FP when you go on a dyno which is equipped with an wide band lambda sensor. I doubt you can go under 75psi without lean conditions. It is very important to dyno-tune your (and any) setup to get the best numbers and to make sure that your engine run safely. Always use a wide band O2 dyno!

The manual of the Cartech says 40-45psi FP at idle for supercharged vehicles.


[This message has been edited by austrian type-R (edited July 24, 2001).]

[ITR1416]

I'll let you know what the final outcome is when I go to the Dyno. It is equip'd with an O2 by the way. Thanks again!

[ITR1416]

Batoutahell thanks for the explaination on the static PSI, it is set to 55. That is what I meant to say when I posted my first comments. I'm a little leary to lower it at this time, I only just installed the JR map controller and for the first time I've been ping free!! I would lower it, but I rather have the peace of mind of knowing what is actually happening when I'm at the dyno and seeing what the O2 shows as far as being lean or rich. Thanks again...

[ITR1416]

I have a B&M FPR going to the JR FMU/FPR. So I do have the ability to adjust both of them. I just don't have a VAFC to fine tune the A/F mixture. I know it's a bit high, that's why I'm trying to find out what I should lower them both to. I'm actually going to go to the dyno, but I thought I'd ask first to see what I might be lowering it to. Thanks!!

[austrian type-R]

You have stock injectors, so the only way to get enough fuel is a high pressure, because the flow rate is only 240cc. When using bigger injectors you MUST retard FP b/c the mixture would be way too rich.

Simply: bigger hole (310cc) needs less FP to fill the combustion camber at the same time with the right quantity of fuel while a smaler hole (240cc) needs more FP to get the same quantity of fuel in the cylinders at the same time!

All clear?


------------------
Supercharged ITR?98 @ 5.5psi
BTC unit, Apexi VAFC, K&N short ram intake, skunk2 cam gears, Kamikaze 2.5", ceramic header, Thermal 3" exhaust, RC 310 injectors, Cartech FMU, AEM FPR
http://www.geocities.com/superchargedtyper
http://albums.photopoint.com/j/Album...622&a=12515817
http://www.geocities.com/autitr/myin...l?991952862150

[ITR1416]

Very clear! Thanks for the explaination. But I'm still curios to know if I'm in the correct PSI range or if I can lower it for more power? Obviously without changing out my injectors, and yes eventually I'll make it to the dyno. I wanna see what other people are running with stock injectors. I know that it also depends on altitude and other factors, but maybe I can compare it to what I have for what it's worth. Thanks again.