JRSC ITR *my fuel pressure

[00ITR006]

Ok, I just ordered my relay and things from radioshack, hopefully it will be here in the next few days.

I went out to my car to find out what my Fuel pressure was according to my B&M FPG.

After some boosted runs, and just idling, it was around 50psi

Now with the vac line disconnected and a golf tee in the vac line, this is the tip-in fuel pressure or (static FP) correct? If so My FP shoots up to 70psi.. No wonder I'm running so rich, I can only imagine what its is at full boost, need a freaking autometer fuel pressure gauge for real..anyways

When i get my relay and resistors from radioshack, and do the mod and lower the static fuel pressure,
DO I HAVE TO SWITCH BACK TO THE STOCK FUEL PUMP..

One more thing for TYPE R owners, Does you boost start to bleed off at the top end, around 6500K-7000K up until Redline,
Mine does I goes up around 5-6psi then starts to taper off around 4psi or so,, Just trying to find out if this is normal, My charger has always done this, since day 1 My tuner said it was normal.

[This message has been edited by 00ITR006 (edited January 23, 2001).]

[Rboosted717]

The falling boost from 7000-on is normal. The cause is due to our cams. When I put the GSR intake cam in for testing, I noticed that the boost held to redline, therefor I conclude its due to our cam setups. However after further testing I decided to go back to the R cam.

------------------
Mike Marsey
'98 ITR #0717
Supercharged w/218whp @ 5.5psi
For all your JRSC type R questions, go to:
http://www.geocities.com/superchargedtyper/

[Batoutahell]

Yes JR says that we need to get rid of the walbro pump and replace it with our stock fuel pump to lower static fuel pressure to 45-50psi.

[mr detail]

If it was my car I would try it with the pump first. It is less initial work to do and it may pay off. On the other hand with the pump in there you may not be able to get the pressure down.

[Batoutahell]

I was wondering if lowering the static fuel pressure to 45-50psi will result in less-efficient combustion? Normally, high fuel pressure is desirable because the spray pattern by the injectors is a very even mist. With lower fuel pressure, the spray pattern by the injectors is less than ideal, right? If we lower static fp to 45-50, should we compensate by modifying the duty cycle of the injectors in an attempt to achieve the better spray pattern? Just a thought.

[Holden]

Most "normal" people would think that 45-50psi fuel pressure is high already!

Don't worry about the spray pattern.

Some people run idle FP as low as 22psi with 320cc injectors.

Greg