Slow spool?
01-26-2009, 09:10 PM
#1
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Slow spool?
This is my first turbo car so I'm still getting accustomed to the whole spool concept. I'm just getting my car tuned and running right, but from what I've read it doesn't seem to be spooling as low as it should. I took a datalog and graphed it, does it look right? If it is spooling slower than it should any idea what could be causing it? This is a 4th gear pull and not significantly different than any other gear. X axis is RPMs, Y Axis is PSI.
boost.jpg
Excel file is also attached if you want to look at the individual values.
Specs on the car are:
'95 1.8 motor
BEGI S3 turbo kit
GT2560 turbo
Megasquirt PNP ecu
Cheap Ebay MBC
Currently running an 18" long 2.5" straitpipe off the downpipe
Any other questions let me know and I'll do my best to answer.
boost.jpg
Excel file is also attached if you want to look at the individual values.
Specs on the car are:
'95 1.8 motor
BEGI S3 turbo kit
GT2560 turbo
Megasquirt PNP ecu
Cheap Ebay MBC
Currently running an 18" long 2.5" straitpipe off the downpipe
Any other questions let me know and I'll do my best to answer.
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01-26-2009, 09:37 PM
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When I first installed the kit I was hitting boost cut really bad, even up to 12psi. I had to adjust the wastegate actuator all the way out in order for it to keep boost right at 10psi. The wastegate lever thing (god I suck at this) is perpendicular to the motor when it's closed, which I'm assuming is correct.
I'll go double check for a boost leak. Any other recommendations?
I'll go double check for a boost leak. Any other recommendations?
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01-26-2009, 11:21 PM
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When I first installed the kit I was hitting boost cut really bad, even up to 12psi. I had to adjust the wastegate actuator all the way out in order for it to keep boost right at 10psi. The wastegate lever thing (god I suck at this) is perpendicular to the motor when it's closed, which I'm assuming is correct.
I'll go double check for a boost leak. Any other recommendations?
I'll go double check for a boost leak. Any other recommendations?
Terms:
Wastegate can is the big round thing that fills with boost
Wastegate actuator rod is the thing that pokes out of the can
Wastegate lever arm is the thing that's on the turbo
The actuator rod should be lightly pulling the lever arm closed when you're off boost. To check this, pull the rod off the lever arm. You should have to tension the rod very slightly to get it to snap over the lever arm. If you pull it off, and you can close the lever arm more, you've got a problem.
If you do that, and you get boost overshoot, you need to port the wastegate.
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01-27-2009, 08:40 AM
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Will do. Unfortauntely I blew the end of my boost controller off, no idea how I managed to do that, but I need to get a new one. Hopefully tonight I can get another graph up. It's definitely a huge improvement.
After breaking the boost controller I played with it a bit and got it to run right at 8psi.
Most definitely.
After breaking the boost controller I played with it a bit and got it to run right at 8psi.
Most definitely.
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01-27-2009, 11:36 AM
#15
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I was originally hitting boost cut at 12psi w/o a boost controller. I adjusted the wastegate actuator out (obviously too much) and later installed the boost controller to raise boost back up to where I wanted.
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02-06-2009, 12:51 PM
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Alright, I'm back again w/ more stupid questions....
The night I tightened the wastegate the car was awesome for a few minutes, then I the adjuster on my boost controller apparently came loose and blew the end off and the the spring went flying. I've been through a couple other boost controllers now but everytime I'm back to the same old problem of building boost very slowly.
The wastegate is tightened down now and I've checked thoroughly for boost leaks. I haven't tested for leaks yet but I'm 99.9% sure it isn't leaking anywhere. I checked my wastegate actuator and it does not hold suction (I can suck on the vacuum hose to it and it doesn't seal). Is it supposed to do that, or could that be my problem? 1 step forward and 2 steps back I guess. Again, any help is greatly appreciated.
The night I tightened the wastegate the car was awesome for a few minutes, then I the adjuster on my boost controller apparently came loose and blew the end off and the the spring went flying. I've been through a couple other boost controllers now but everytime I'm back to the same old problem of building boost very slowly.
The wastegate is tightened down now and I've checked thoroughly for boost leaks. I haven't tested for leaks yet but I'm 99.9% sure it isn't leaking anywhere. I checked my wastegate actuator and it does not hold suction (I can suck on the vacuum hose to it and it doesn't seal). Is it supposed to do that, or could that be my problem? 1 step forward and 2 steps back I guess. Again, any help is greatly appreciated.
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02-06-2009, 10:03 PM
#18
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Alright, I'm back again w/ more stupid questions....
The night I tightened the wastegate the car was awesome for a few minutes, then I the adjuster on my boost controller apparently came loose and blew the end off and the the spring went flying. I've been through a couple other boost controllers now but everytime I'm back to the same old problem of building boost very slowly.
The wastegate is tightened down now and I've checked thoroughly for boost leaks. I haven't tested for leaks yet but I'm 99.9% sure it isn't leaking anywhere. I checked my wastegate actuator and it does not hold suction (I can suck on the vacuum hose to it and it doesn't seal). Is it supposed to do that, or could that be my problem? 1 step forward and 2 steps back I guess. Again, any help is greatly appreciated.
The night I tightened the wastegate the car was awesome for a few minutes, then I the adjuster on my boost controller apparently came loose and blew the end off and the the spring went flying. I've been through a couple other boost controllers now but everytime I'm back to the same old problem of building boost very slowly.
The wastegate is tightened down now and I've checked thoroughly for boost leaks. I haven't tested for leaks yet but I'm 99.9% sure it isn't leaking anywhere. I checked my wastegate actuator and it does not hold suction (I can suck on the vacuum hose to it and it doesn't seal). Is it supposed to do that, or could that be my problem? 1 step forward and 2 steps back I guess. Again, any help is greatly appreciated.
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