Fuel Pressure?

[NJTurbo]

Running about 19lbs of boost with vaccum off what should fuel pressure be?










njturbo
87GN 13.2ET
87T-TYPE 13.8 ET Stock

 

[timothydog]

I'd say around 42 lbs (+/-2) with the vacuum line off.

 

[NJTurbo]

Thanks.

 

[SloNoMo]

T-Dog ,,,

What about 22psi with the line off.............!


Thanks,
Mack

 

[NJTurbo]

22 with line off?? way to low.

 

[Mr URL]

Depends on what the chip programmer based fueling on, what your combo is, what your scantool tells you (are you within safe operating O2's?), and what your e.t./mph gain/loss tells you. Some cars like it fat and some like it lean. Some chips have WOT BLM locked at 128 and some don't.

42 psi line off may work for one car but not work for mine. Most cars have their fuel pressures anywhere from 40-48 psi static (line off) as an example.

 

[SloNoMo]

Ooops

Maybe I should re-phrase the question.............I will be running 22 pounds of boost, I'm thinking the fuel pressure should be around 46-48psi with the line off (static) pretty close???

Thanks,
Mack

Originally posted by njturbo
22 with line off?? way to low.

 

[azgn]

start at the baseline setting specified by the chip......at 46-48, you are prolly going to be rich and may outrun your fuel pump (with 22 lbs boost, your fuel pressure should be 68-70 psi....very close to the limit on a 340)

 

[SloNoMo]

Thanks!!

I appreciate the response Woody...going to Fontana Racetrack on Saturday, will start with a baseline of 46-48 psi to start with and tune from there....I would rather be a little rich than a little lean...............Let you fellas know what happened


Thanks,
Mack

 

[Gn-Krazzie]

I am running 50 PSI Line ON with a T3/T4B turbo , the chip i believe may be a kenne bell. How closely does the fuel ratio track the fuel pressure. I prefer to run alittle rich to protect the motor and it appears to pull good at this setting. I do get the odd pop now and again which i understand is from a lean condiction.??. I run 15-16 PSI Boost on the street only. I have the stocker pump ( in tank ) and a Bosche In-line Pump which is old school i know. But hey it works have peaked at 20 PSI in certain situations.

What is too much fuel pressure doing to my injectors ?? I am thinking its not affecting the spray pattern just equates to more flow.

Is this odd pop @ WOT lean condition or is an electrical system problem.

 

[azgn]

Mack

nothing wrong with being rich.....assume you have a scan tool and can tune with that.....good luck!

 

[SloNoMo]

Woody,

Yep, have had T-link since day one, and tune with that on a regular basis...............Thanks for the advise


Mack

 

[UNGN]

Originally posted by Gn-Krazzie
I am running 50 PSI Line ON with a T3/T4B turbo , the chip i believe may be a kenne bell. How closely does the fuel ratio track the fuel pressure. I prefer to run alittle rich to protect the motor and it appears to pull good at this setting. I do get the odd pop now and again which i understand is from a lean condiction.??. I run 15-16 PSI Boost on the street only. I have the stocker pump ( in tank ) and a Bosche In-line Pump which is old school i know. But hey it works have peaked at 20 PSI in certain situations.

What is too much fuel pressure doing to my injectors ?? I am thinking its not affecting the spray pattern just equates to more flow.

Is this odd pop @ WOT lean condition or is an electrical system problem.

The big problem running a stock pump/puller is the fuel sock on the stocker. The bosch is supplying adequate pressure, but you can't ensure the stocker will supply adequate volume (especially if the sock collapses). 50 psi line on is too high and is way beyond what is considered normal. The pop could be from a too rich or too lean condition. I'd lower the fuel pressure and seriously look into a single intank pump.

If you are using fuel presure to overcome knock, don't. That is what octane is for. It's a general rule that people that increase their fuel pressure to overcome knock are slower than people that add octane.

If somebody brags to me that their "car doesn't knock on pump gas at 20 psi" I feel it is no great accomplishment if it only runs 13.5's at 20 psi.