turbo issues... any insight?
Thread Starter
Launching!
Joined: Dec 2001
Posts: 263
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From: Jacksonville, FL
turbo issues... any insight? okay...
had my car on the dyno today, second time since the turbo tech kit has been installed. here is a list of my mods..
TurboTech 60-1 (6psi)
Comp 918 springs
chromoly pushrods
Walbro 340 intank fuel pump
30lb fuel injecters (rated @ 45psi, i'm pushin 64psi)
meth/alchy injection..
those are the main things that i can think of..
well to make a long story short. Every pull on the dyno, the car makes less and less power. Not just a little less. It's losing about 100hp. Everything checks out fine.. with the exception of 2 things...
A.) misfiring on #7 (compression and lead-down tests come back fine)
B.) maf is reading about 100g less than it should.
boost gage is reading fine, fuel is perfect, timing is great. but the #s just die after 4k rpms.
Here are the pics of the dyno... check the link.
power drop
Best dyno run
Worse dyno run, 4th straight run, no changes
Any ideas?
had my car on the dyno today, second time since the turbo tech kit has been installed. here is a list of my mods..
TurboTech 60-1 (6psi)
Comp 918 springs
chromoly pushrods
Walbro 340 intank fuel pump
30lb fuel injecters (rated @ 45psi, i'm pushin 64psi)
meth/alchy injection..
those are the main things that i can think of..
well to make a long story short. Every pull on the dyno, the car makes less and less power. Not just a little less. It's losing about 100hp. Everything checks out fine.. with the exception of 2 things...
A.) misfiring on #7 (compression and lead-down tests come back fine)
B.) maf is reading about 100g less than it should.
boost gage is reading fine, fuel is perfect, timing is great. but the #s just die after 4k rpms.
Here are the pics of the dyno... check the link.
power drop
Best dyno run
Worse dyno run, 4th straight run, no changes
Any ideas?
Thread Starter
Launching!
Joined: Dec 2001
Posts: 263
Likes: 0
From: Jacksonville, FL
Re: turbo issues... any insight? it was actually running rather rich the entire time. in the 10:1 range for the most part. it never even touched 11:1 until it reached over 5k rpm. the highest it peaked was 12:1. i'll have to take a pic of the A/F.
Thread Starter
Launching!
Joined: Dec 2001
Posts: 263
Likes: 0
From: Jacksonville, FL
TECH Fanatic
Joined: Mar 2002
Posts: 1,044
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Re: turbo issues... any insight? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Jax White TA:
<strong>A.) misfiring on #7 (compression and lead-down tests come back fine)</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">OUCH! I hate to see that. The infamous #7 cylinder. I'm glad to see the leak-down is good. What was the percentage of leak-down? Under ten is ok.
Check the wire and plug on number seven, and swap the two neighboring injectors and check to see if the misfire moves with it.
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Jax White TA:
<strong>
B.) maf is reading about 100g less than it should.
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">If it's reading 100g LESS, then you should be leaning out the motor bad. Swap in a friend's MAS from the same type of vehicle.
Also, if you're running the Alchy injection at the same time, turn it off, it is going to veil the real problem. Redyno or ATAP without it. Remember that the LS1/6 intake is NOT a wet flow, so it sucks for that. You may be too lean on the tuning and covering it up with the alchy, and then the poor wet flow characteristics are causing your #7 anomoly (sp?).
Let us know.
SC-
<small>[ March 28, 2003, 09:47 AM: Message edited by: SS00Blue ]</small>
<strong>A.) misfiring on #7 (compression and lead-down tests come back fine)</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">OUCH! I hate to see that. The infamous #7 cylinder. I'm glad to see the leak-down is good. What was the percentage of leak-down? Under ten is ok.
Check the wire and plug on number seven, and swap the two neighboring injectors and check to see if the misfire moves with it.
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Jax White TA:
<strong>
B.) maf is reading about 100g less than it should.
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">If it's reading 100g LESS, then you should be leaning out the motor bad. Swap in a friend's MAS from the same type of vehicle.
Also, if you're running the Alchy injection at the same time, turn it off, it is going to veil the real problem. Redyno or ATAP without it. Remember that the LS1/6 intake is NOT a wet flow, so it sucks for that. You may be too lean on the tuning and covering it up with the alchy, and then the poor wet flow characteristics are causing your #7 anomoly (sp?).
Let us know.
SC-
<small>[ March 28, 2003, 09:47 AM: Message edited by: SS00Blue ]</small>
TECH Addict
Joined: Nov 2001
Posts: 2,659
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From: Bellevue, Wa
Re: turbo issues... any insight? I would tend to agree with the above theory.
30# injectors are WAY to small.
I too think your covering up a problem with the water/alky.
Tune without it first, then bring it online and retune for it.
Thats how I did it. Worked well for me.
30# injectors are WAY to small.
I too think your covering up a problem with the water/alky.
Tune without it first, then bring it online and retune for it.
Thats how I did it. Worked well for me.
Thread Starter
Launching!
Joined: Dec 2001
Posts: 263
Likes: 0
From: Jacksonville, FL
Re: turbo issues... any insight? 30lb injectors at 45PSI.. so mine should be closer to 33 - 34lb because i'm at 64psi. right?
I've already tried swapping the maf, same problem.
with and without the alky, the a/f stays the same and the dyno #s continue to die off.
i forgot to mention, i'm having quite a bit of crankcase pressure. enough to shot the dip stick out of the dipstick tube. So i certainly have to fix that with a 1 way check valve and a breather on the driver side valve cover.
I've already tried swapping the maf, same problem.
with and without the alky, the a/f stays the same and the dyno #s continue to die off.
i forgot to mention, i'm having quite a bit of crankcase pressure. enough to shot the dip stick out of the dipstick tube. So i certainly have to fix that with a 1 way check valve and a breather on the driver side valve cover.
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Thread Starter
Launching!
Joined: Dec 2001
Posts: 263
Likes: 0
From: Jacksonville, FL
Re: turbo issues... any insight? okay,
here is something i recently found out.
being that the motor is under boost, the PCV valve is unable to stop the boosted air from entering the crankcase. this is causing the crankcase to become pressurized; thus forcing oil past the rings and fouling plugs. With a 1way check valve installed (bought from ET-Performance) this is prevent the crankcase from becoming pressurized.
Maybe this is where my boost is going and will bring my #s back to where they should be. However, it still doesnt explain why the MAF is reading 100g less than it should. hmmm
here is something i recently found out.
being that the motor is under boost, the PCV valve is unable to stop the boosted air from entering the crankcase. this is causing the crankcase to become pressurized; thus forcing oil past the rings and fouling plugs. With a 1way check valve installed (bought from ET-Performance) this is prevent the crankcase from becoming pressurized.
Maybe this is where my boost is going and will bring my #s back to where they should be. However, it still doesnt explain why the MAF is reading 100g less than it should. hmmm
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TECH Apprentice
Joined: Nov 2001
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From: malmstrom Air Force Base, Montana
Re: turbo issues... any insight? when my dipstick shot out I had a shattered piston, cracked block, and a bent rod... <img border="0" title="" alt="[Frown]" src="gr_sad.gif" />
Staging Lane
Joined: Mar 2003
Posts: 56
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From: Bay Area California
Re: turbo issues... any insight? when my dipstick shot out I had a shattered piston, cracked block, and a bent rod...
Holy crap! COuld you go on about that story? I would like to know what kind of engine you were running, what kind of compression, boost if any and all that. So I dont do the same thing hopefully <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
Holy crap! COuld you go on about that story? I would like to know what kind of engine you were running, what kind of compression, boost if any and all that. So I dont do the same thing hopefully <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />