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| Forum name | Turbo/Nitrous Tech |
| Topic subject | okay why is it that we need 90 psi FP at 15 psi of boost with 440's |
| Topic URL | https://forums.2gnt.com/dcboard.php?az=show_topic&forum=i8&topic_id=34843 |
34843, okay why is it that we need 90 psi FP at 15 psi of boost with 440's
Posted by jamesman, Nov-21-02 02:45 AM
i am running 14 psi of boost right now and i am running a max fuel pressure of about 65 psi. I am getting A/F voltage at WOT across the entire RPM range of .93/.94 my LTFT's are all in the -20's ms STFT's are all within +- 10 during all rpms and loads. I was reading somewhere that people are running 90+ psi of fuel pressure with 440 injectors at 15 psi. isn't that a bit much? or am i missing something. Also at 15 psi of boost what HP should i be making with 8.8 pistons?
thanks
James
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34844, RE: okay why is it that we need 90 psi FP at 15 psi of boost with 440's
Posted by MuRiX, Nov-21-02 03:04 AM
The amount of pressure you run is mainly going to effect the flow rate of your injectors so it is not an exact number. If what you have is working fine then I would not worry too much about it unless it is showing that perhaps you badly down on power and therefore rich? What is your timing like?
Oh, I am running 60psi on my 525's for 18psi on my S16G with my setup.
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34845, RE: okay why is it that we need 90 psi FP at 15 psi of boost with 440's
Posted by jamesman, Nov-21-02 08:36 AM
my timing is alright i think, about 15-17 degrees at WOT. I don't think i am making as much power as i should be though. I am running 65 psi max at 14.7 psi boost with 440 cc injectors. MY egts will reach about 1600 when i get to the end of 3rd gear. my AF is steady .93-94.
what i wonder is, is 65 psi enough? I don't think i need more, but maybe i'm missing something
thanks
james
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34846, RE: okay why is it that we need 90 psi FP at 15 psi of boost with 440's
Posted by XtremeRS, Nov-21-02 08:47 AM
If you are reaching 1600 degrees at WOT, then you need more fuel. For 15 psi of boost, .93 o2's is a bit lean. Richen it up some to around .95 or .96. Tune more by your EGT readings. Shoot for 1500-1550 degrees at WOT. I ran 10 psi with .93 o2's in third gear WOT, and detonated...
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34847, RE: okay why is it that we need 90 psi FP at 15 psi of boost with 440's
Posted by jamesman, Nov-21-02 09:29 AM
okay i'll try that.
what i was wondering is that i have played with my fuel delivery amounts and at WOT i have even been able to make my EGT's drop. My question is, Say When I floor it. should my EGT's rise and then top out at 1550, or should I be reaching 1550 at like say the top of 3rd gear? cause i know that if i reach 1550 in 3rd, then i will exceed that if i continue into 4th gear. I'm pretty sure i can make it where no matter what the max egt i will see is 1550 by dumping more fuel in, Is this what i am after?
thanks
James
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34848, RE: okay why is it that we need 90 psi FP at 15 psi of boost with 440's
Posted by MuRiX, Nov-21-02 09:47 PM
keep in mind our engines like to run really rich, like in the tune of 11.1 - 11.5. You should try to keep your EGT's slightly lower for safety. The suprising thing is you will not lose as much power as I originally thought (I would guess due to timing)
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