How High Is Your Fuel Pressure?
- Thread starter messejme
- Start date
It varies a little fom truck to truck, but you should be able to hold at least 21,000 on a hot tune. BTW welcome to the site.
OPPSS!!! Good answer for a DIFFERENT QUESTION!:
Normally if you are tuning on the street with stock CP3 truck, the peak power will occur when fuel demand (pulse width) pulls the rail down about 10% from commanded pressure. Usually about a 3100-3200 microsecond shot.
If your truck is an LLY or LB7 this means pulling it down from 23000PSI down to about 20500 roughly. 19500 to 21000 is where the peak power will usually be.
For LBZ's go down to about 23,000 PSI. My datalogging ain't working well on the LMM.
Normally if you are tuning on the street with stock CP3 truck, the peak power will occur when fuel demand (pulse width) pulls the rail down about 10% from commanded pressure. Usually about a 3100-3200 microsecond shot.
If your truck is an LLY or LB7 this means pulling it down from 23000PSI down to about 20500 roughly. 19500 to 21000 is where the peak power will usually be.
For LBZ's go down to about 23,000 PSI. My datalogging ain't working well on the LMM.
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Your engine will not report numbers higher than 28000PSI IIRC.
I found no big advantage to programming past 26000 on a stock truck.
I found no big advantage to programming past 26000 on a stock truck.
Whats the best approach for pulling the rail down, adding pulse width, timing or a combination
Pulse width pulls rail pressure down, or higher commanded pressure will also.
This is why a "max effort" tune will seldom see a gain by using a rail pressure fooler. If you are already pulling the rail down, telling it you want more fuel is silly.
This is why a "max effort" tune will seldom see a gain by using a rail pressure fooler. If you are already pulling the rail down, telling it you want more fuel is silly.
my max commanded pressure is 180 Mpa . I got a P0088 code while beating on it. My pressure must have spiked higher than 180 Mpa.
I had been running a 2050 ms pulse width max (gotta do the trans) and 180 Mpa max pressure calibration for six weeks. I could get a p1093 if I held it nailed for a while (1/8 milish) So I shimmed the FPRV thats when I got the P0088 code. I am already allowing higher rail pressure 25,000-26,000 psi. My CP3 is obviously making more than 26,000 psi how much higher and for how long I will log.I know I can ignore the P0088 if I want but I dont like disabling these type of warnings.