Pressure instability.
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Pressure instability.
This is really hard to explain so bare with me.
Normal boost is anywhere from 7-9psi on my car right now.
For some reason, when I floor it, boost will almost never rise above 6psi.
If I use about 40% throttle. It will stay at 8-9psi. If after this time I press the gas all the way down. It lowers itself down to 6-7psi and will stay there. Othe times it wont rise above 5-6psi.
This is very annoying, as you can FEEL the difference in power. Basicly if I floor my car it FEELS slower then if I only use 40% throttle. What could be causing this?
Normal boost is anywhere from 7-9psi on my car right now.
For some reason, when I floor it, boost will almost never rise above 6psi.
If I use about 40% throttle. It will stay at 8-9psi. If after this time I press the gas all the way down. It lowers itself down to 6-7psi and will stay there. Othe times it wont rise above 5-6psi.
This is very annoying, as you can FEEL the difference in power. Basicly if I floor my car it FEELS slower then if I only use 40% throttle. What could be causing this?
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Joined: Aug 2002
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Velocity my freind.. thats your problem you lost it when you opened the throttle wide open...
Some thing is too big, what ever you changed put it back. It may be the intercooler, piping, TB, who knows. but your losing velocity.
Do you get higher boost in the higher gears? You should make more boost in higher gears than lower, like 1st VS 4th WOT.
Some thing is too big, what ever you changed put it back. It may be the intercooler, piping, TB, who knows. but your losing velocity.
Do you get higher boost in the higher gears? You should make more boost in higher gears than lower, like 1st VS 4th WOT.
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Registered User
Joined: Aug 2002
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Turn the boost up and retard the timing.. run race gas.. all fixed...
You should get 2 to 3 psi more in 4th and 5th gear as the load on the engine is greater, VS the load on the engine in the lower gears...
You should get 2 to 3 psi more in 4th and 5th gear as the load on the engine is greater, VS the load on the engine in the lower gears...
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custom parts is our perfection.
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Joined: Sep 2001
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what size turbo u got? sounds like its pretty small if youre hitting 8-9psi at 40% throttle. my guess is your turbo is being maxxed out and cannot push enough air at WOT to keep the manifold pressure up.
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Joined: Aug 2002
Posts: 192
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Jeff you've got to do some sort of trial to determine what the issue truly is.
O2 sensors are cheap $25... Anyways the O2 sensor does nothing @ WOT.. the fuel maps and timing is preset for WOT.
I assume you said that because the race gas eats up O2 sensors?
So what happens when you turn the boost up, does it still act the same.
I am starting to think you have a horrible connection some where and it is causing turbulence, the faster you go and the more load you put on it. Thus making the pressurized air to start stacking in the intake..
Are you running stock intake manifold?
O2 sensors are cheap $25... Anyways the O2 sensor does nothing @ WOT.. the fuel maps and timing is preset for WOT.
I assume you said that because the race gas eats up O2 sensors?
So what happens when you turn the boost up, does it still act the same.
I am starting to think you have a horrible connection some where and it is causing turbulence, the faster you go and the more load you put on it. Thus making the pressurized air to start stacking in the intake..
Are you running stock intake manifold?
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custom parts is our perfection.
custom parts is our perfection.
