CTSC FMU
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CTSC FMU
Anybody still using Comptechs RRFPR / FMU ? I'm noticing a lot of inconsistency with mines. One day I will be hitting low 12's AFRs up top, next thing you know its hitting low 13s. I know temperatures could effect it so I'm tuning my leanest AFR when it is cold out. Next day..warmer temps and I go at it and I'm getting higher AFR's then the previous night before..if temperatures higher, shouldn't the AFR's go on the rich side? Am I missing something here?
I also have my FMU pretty much maxed out at only 5~6 PSI. Is that normal? 3-4 thread showing above locknut on 5~6 psi??
If you have a CTSC running stock boost. What is your FMU set at?
Current setup:
MY02 CTSC w/ FMIC
SOS 3.6" Pulley - 5~6 PSI at 9k
Vacuum source for FMU is isolated and not Tee'd off to anything.
I also have my FMU pretty much maxed out at only 5~6 PSI. Is that normal? 3-4 thread showing above locknut on 5~6 psi??
If you have a CTSC running stock boost. What is your FMU set at?
Current setup:
MY02 CTSC w/ FMIC
SOS 3.6" Pulley - 5~6 PSI at 9k
Vacuum source for FMU is isolated and not Tee'd off to anything.
Joined: Nov 2009
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From: Gurnee, IL
Well, you do have that fmic that is giving you Cooler air than standard.
Yes, the temperature does make a difference....outside and under your hood. Mine does the same thing. Going wot after the car has just warmed up will give me a leaner ratio than when I have been driving around a while.
Tune for the richer side, otherwise you might have to run a larger pulley while it's cold out. Another option for limiting boost is an intake restrictor or a boost limited valve.
Yes, the temperature does make a difference....outside and under your hood. Mine does the same thing. Going wot after the car has just warmed up will give me a leaner ratio than when I have been driving around a while.
Tune for the richer side, otherwise you might have to run a larger pulley while it's cold out. Another option for limiting boost is an intake restrictor or a boost limited valve.
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Yea I am tuning my Leanest when it is coldest outside to low 12s. That way if it does ever get colder it would go slightly higher. But normal day to day driving would be warmer which should yield richer afr's around mid-high 11s.
What I don't get is after my lean tune on coldest temps. Next day, warmer temp, I get even leaner AFR's..
What is your FMU set at?
And what is the Fuel difference fro AP1 and AP2?
Maybe I'm getting heat soak from the tuning..
What I don't get is after my lean tune on coldest temps. Next day, warmer temp, I get even leaner AFR's..
What is your FMU set at?
And what is the Fuel difference fro AP1 and AP2?
Maybe I'm getting heat soak from the tuning..
Joined: Nov 2009
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From: Gurnee, IL
Hmm, idk?
My fmu is showing only one thread. The difference though between cold an hot is only a max of 0.3 on the wideband and not a whole point.
I'm using the ap1 specific fmu on my ap2.
Is your boost consistent? Belt tight? What fuel pump do you have?
My fmu is showing only one thread. The difference though between cold an hot is only a max of 0.3 on the wideband and not a whole point.
I'm using the ap1 specific fmu on my ap2.
Is your boost consistent? Belt tight? What fuel pump do you have?
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How much boost are you running to have your FMU to that point of 1 thread showing? And your AFR's?
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Well, you do have that fmic that is giving you Cooler air than standard.
Yes, the temperature does make a difference....outside and under your hood. Mine does the same thing. Going wot after the car has just warmed up will give me a leaner ratio than when I have been driving around a while.
Tune for the richer side, otherwise you might have to run a larger pulley while it's cold out. Another option for limiting boost is an intake restrictor or a boost limited valve.
Yes, the temperature does make a difference....outside and under your hood. Mine does the same thing. Going wot after the car has just warmed up will give me a leaner ratio than when I have been driving around a while.
Tune for the richer side, otherwise you might have to run a larger pulley while it's cold out. Another option for limiting boost is an intake restrictor or a boost limited valve.
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Might be getting more inconsistencies with the fmic, do to boost leaks. wider range of IAT. Could already have a damaged diaphragm in the fpr causing inconsistent fuel pressure to injectors, could have dirty or damaged injectors. vacuum leak to fpr, manifold or TB leaks. All possible stuff. Threads showing is just a generality, what matters is what’s going on inside with the spring tension and what that’s doing to the diaphragm. One fpr might be ok at 3 threads showing, and another may not. Springs get weak over time, which means if your running max for long, you will have to increase tension to maintain your same pressure over time, if your spring is bottomed out, then you are putting bad pressure on the diaphragm and can warp it. You can pull the top off the fpr and check it without too much trouble. replace spring and diaphragm if necessary.
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Might be getting more inconsistencies with the fmic, do to boost leaks. wider range of IAT. Could already have a damaged diaphragm in the fpr causing inconsistent fuel pressure to injectors, could have dirty or damaged injectors. vacuum leak to fpr, manifold or TB leaks. All possible stuff. Threads showing is just a generality, what matters is what’s going on inside with the spring tension and what that’s doing to the diaphragm. One fpr might be ok at 3 threads showing, and another may not. Springs get weak over time, which means if your running max for long, you will have to increase tension to maintain your same pressure over time, if your spring is bottomed out, then you are putting bad pressure on the diaphragm and can warp it. You can pull the top off the fpr and check it without too much trouble. replace spring and diaphragm if necessary.
Any way to test vacuum leaks to FMU without a gauge?
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Originally Posted by s2000Junky' timestamp='1313687553' post='20890620
Might be getting more inconsistencies with the fmic, do to boost leaks. wider range of IAT. Could already have a damaged diaphragm in the fpr causing inconsistent fuel pressure to injectors, could have dirty or damaged injectors. vacuum leak to fpr, manifold or TB leaks. All possible stuff. Threads showing is just a generality, what matters is what’s going on inside with the spring tension and what that’s doing to the diaphragm. One fpr might be ok at 3 threads showing, and another may not. Springs get weak over time, which means if your running max for long, you will have to increase tension to maintain your same pressure over time, if your spring is bottomed out, then you are putting bad pressure on the diaphragm and can warp it. You can pull the top off the fpr and check it without too much trouble. replace spring and diaphragm if necessary.
Any way to test vacuum leaks to FMU without a gauge?
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Originally Posted by mrscbw' timestamp='1313688361' post='20890679
[quote name='s2000Junky' timestamp='1313687553' post='20890620']
Might be getting more inconsistencies with the fmic, do to boost leaks. wider range of IAT. Could already have a damaged diaphragm in the fpr causing inconsistent fuel pressure to injectors, could have dirty or damaged injectors. vacuum leak to fpr, manifold or TB leaks. All possible stuff. Threads showing is just a generality, what matters is what’s going on inside with the spring tension and what that’s doing to the diaphragm. One fpr might be ok at 3 threads showing, and another may not. Springs get weak over time, which means if your running max for long, you will have to increase tension to maintain your same pressure over time, if your spring is bottomed out, then you are putting bad pressure on the diaphragm and can warp it. You can pull the top off the fpr and check it without too much trouble. replace spring and diaphragm if necessary.
Might be getting more inconsistencies with the fmic, do to boost leaks. wider range of IAT. Could already have a damaged diaphragm in the fpr causing inconsistent fuel pressure to injectors, could have dirty or damaged injectors. vacuum leak to fpr, manifold or TB leaks. All possible stuff. Threads showing is just a generality, what matters is what’s going on inside with the spring tension and what that’s doing to the diaphragm. One fpr might be ok at 3 threads showing, and another may not. Springs get weak over time, which means if your running max for long, you will have to increase tension to maintain your same pressure over time, if your spring is bottomed out, then you are putting bad pressure on the diaphragm and can warp it. You can pull the top off the fpr and check it without too much trouble. replace spring and diaphragm if necessary.
Any way to test vacuum leaks to FMU without a gauge?
[/quote]
Definately no leaks to the FMU. All connection points are zip tied as well.