Those of you running 8-9 psi

**217gsr** · June 18th, 2002, 05:55 PM

What are your fuel pressures (static/idle) when adjusted at the FMU? What about the static when adjusted at the FPR? What is your max fuel pressure when at WOT?

I'm interested in seeing what everyone else's pressures are with stock injectors.

If you have aftermarket injectors (either 290 or 310cc), please tell me how I can "calculate" what your pressures would be if you had the stock injectors. Thanks all.

**cpa** · June 18th, 2002, 09:40 PM

I have the JR upgraded crank pulley for my GSR and saw about 8.5 psi on the dyno. With stock injectors and the JR FMU, I had the JR FMU static set at 70 (I could set it lower, down to 60 but it would ping easier and had less power across the curve), with max pressures of 100+. I'd assume about 110 psi based on the boost reading and 5:1 rise rate, and my B&M underhood gauge reading 100+. I only had the stock FPR on at the time, so I'm no help there.

I've been trying to get a set of prelude injectors to idle (RC flow sheets read 292-294 cc), but havent been successful. JRCivic (hopefully I quote this right) told me that around 34 psi static on the AEM FPR and 42 static on the Cartech FMU would be close, and the rise rate would be around 4:1, meaning max fuel pressures around 75 psi or so at 8-9 psi boost.

I wish I could get the injectors to work so I could then put on the water injection and then a stepper and get my pressures back up around 90psi! [img]smile.gif[/img]

**93hb** · October 1st, 2005, 10:49 PM

anymore on this....

cause this forum is dead

**promotion** · October 3rd, 2005, 10:35 PM

I talked to Jackson Racing about the set up I want; 310cc RC injectors with 9-10 psi boost. They told me that I may run out of fuel with stock injectors above 8 psi. Also, with a huge amount of fuel presure, the stock injectors would have a hard time opening and may open a little too late. With the 310cc injectors, I could run the fuel presure at the recomended settigs for stock injectors at 6 psi for my 9-10 psi set up.

**93hb** · October 4th, 2005, 08:08 AM

what is the recommended setting for the fuel pressure with stock injectors at 6psi?

**JRCivic** · October 4th, 2005, 02:21 PM

With 310cc injectors, your static fuel pressure should be between 27 and 30 psi. Also, your rise-rate under boost should be approximately 3:1... and since the JR FMU is not adjustable, you will be quite rich under boost.

**93hb** · October 5th, 2005, 04:51 PM

isn't 27-30psi fuel pressure too low?

stock fuel pressure is at what... 42psi?

**Jaker** · October 6th, 2005, 01:09 AM

Originally posted by 93hb:
isn't 27-30psi fuel pressure too low?

stock fuel pressure is at what... 42psi?

<font size="2" face="Verdana, Helvetica, sans-serif">42 PSI with 240cc injectors. If you leave it at 42 PSI with the 310cc injectors, you'll have way too much fuel at idle, hence the drop to 27 PSI.