corvette central tip?
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Joined: Jan 2008
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From: hinton ia
corvette central tip?
i have a question in the latest corvette central catalog they had a horsepower tip they said to cap the fuel pressure regulator and vacuum line for a 4psi increase my question is what good does this do?
i mean if you up the pressure wont the computer just shorten the injector pulse width? thus resulting in the same amount of fuel?at wot when you would need the extra pressure there is no vacuum anyway so at wot how would there be any difference? has anyone done this or heard of this before? thank pat
i mean if you up the pressure wont the computer just shorten the injector pulse width? thus resulting in the same amount of fuel?at wot when you would need the extra pressure there is no vacuum anyway so at wot how would there be any difference? has anyone done this or heard of this before? thank pat
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
From what I know, the PCM has no way of knowing what the fuel pressure is. So if the pressure were greater for a given pulse width to the injectors, then more fuel would flow. However, I think the O2 sensor would feedback that the ratio is off (unless WOT) and shorten the pulse width (as you said).
Bottom line....I do not think one would gain any increase. However, many people have increased the fuel pressure claiming a power increase. Should be easy to try and find out.
Bottom line....I do not think one would gain any increase. However, many people have increased the fuel pressure claiming a power increase. Should be easy to try and find out.
Drifting
Joined: Oct 2006
Posts: 1,934
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From: Citrus Heights California
I read somewhere that increasing your fuel pressure would increase hp. I tried it and it ran rich. That will slow it down. You need to have the correct air fuel ratio for optimum performance.
Burning Brakes
Joined: Feb 1999
Posts: 1,157
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From: Encino CA
I believe that with these late model cars where the computer compensates for everything, increasing pressure will end up with shorter pulse width and vice versa. However, I think I recall hearing that a small increase in pressure of maybe 2 or 3 psi over stock (46 psi) will result in a better atomized mist from the injector resulting in some improvement (i.e., higher pressure with finer mist and shorter pulse versus lower pressure and coarser mist with longer pulse).
I am certainly no expert and seem to remember several educated posts here once upon a time that went on for pages about the science of fuel delivery so if you search through the archives you might stumble across these.
Doug
I am certainly no expert and seem to remember several educated posts here once upon a time that went on for pages about the science of fuel delivery so if you search through the archives you might stumble across these.
Doug
Burning Brakes
Joined: Aug 2006
Posts: 878
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From: BC
it should be noted though that when over a certain amount of throttle ~ 75% ish (programable) the ECM ignores the oxygen sensor in the exhaust. A little extra fuel MAY help at these large throttle openings but that would depend on its Air/Fuel ratio to start wth.
Team Owner
Joined: Aug 2005
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From: Riverside County Southern California
Co-winner 2020 C4 of the Year - Modified
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I read about this and I installed two aftermarket FPR years ago. You get better results if you increase 1-2 PSI max from the original FPR readout. If you add more than 1-2 PSI, the car will run rich and the LT engine may have trouble at start-up.
Yes, increasing the fuel pressure will give you noticeable power.
Yes, increasing the fuel pressure will give you noticeable power.
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Joined: Jun 2004
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From: WI
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