STS Z06 dropping boost
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STS Z06 dropping boost C6 Z06 forged motor with sts system, we have checked over all pipes and everything is solid. The wastegates have 10# springs, but the car only hits 7psi and then by 6500rpm it has dropped to 5.5 or so. But it is very worth noting that when we take the vac lines off the turbos, the turbos spool to 15psi no problem and you can feel the power, so the turbos are definitely not the culprit.
We are not sure if the motor is somehow eating up the boost or what? We have also looked over the wastegates and done some tests and they seem to be fine.
Wondering if anyone has any input?
Wastegate and boost guage reference is right off the manifold.
We are not sure if the motor is somehow eating up the boost or what? We have also looked over the wastegates and done some tests and they seem to be fine.
Wondering if anyone has any input?
Wastegate and boost guage reference is right off the manifold.
Last edited by SSnakekiller; Jun 10, 2012 at 08:51 AM. Reason: added details
With the sts twins, you lose a little boost between the piping and fmic. Mine was the same before adding a manual boost controller. About 2 or 3 lbs of loss. With adding a controller, you can just adjust up to the desired boost level. I have my manual split to both waste gates.
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With the sts twins, you lose a little boost between the piping and fmic. Mine was the same before adding a manual boost controller. About 2 or 3 lbs of loss. With adding a controller, you can just adjust up to the desired boost level. I have my manual split to both waste gates.
But none of this explains how it goes from 7psi at 3500rpm and ramps down to 5.5psi by 6500.
Did/does yours do that? Bleed off?
Yes, mine is referenced off the turbo. I run 15 psi and I do see it drop a pound or so at high rpm. I don't feel any difference when it does. That's about shift time anyway. I can see it being much more noticeable at lower boost levels.
The cam and springs could be the culprit. I have a custom ground boost cam and comp springs. When I had an sts camaro, I had a 10# spring and stock internals. Boost would max out around 8.5-9 psi. It was non intercooled, so I imagine I'd have lost another lb with the additional piping.
Im not real familiar with boost drop associated with rear mount setups, but electronic boost controllers like the eboost street or eboost 2 have boost drop compensation that will fix exactly what your describing.
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The cam and springs could be the culprit. I have a custom ground boost cam and comp springs. When I had an sts camaro, I had a 10# spring and stock internals. Boost would max out around 8.5-9 psi. It was non intercooled, so I imagine I'd have lost another lb with the additional piping.
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On The Tree
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Where is your wastegate bottom vac source referenced from? If it is from the manifold, you shouldnt see a boost drop, but if it is off the turbo you will.
But none of this explains how it goes from 7psi at 3500rpm and ramps down to 5.5psi by 6500.
Did/does yours do that? Bleed off?
But none of this explains how it goes from 7psi at 3500rpm and ramps down to 5.5psi by 6500.
Did/does yours do that? Bleed off?
similar problem happened to me check your air filter and seem if its clogged i know on my sts kit the filter is in the rear fender well if yours is as well check for tire rubber my filter crimped close due to it cosing me to loose boost
Teching In
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Same pis My 08 z06 had same problem ,would only get to 10 psi even with boost pressure piped to top of waste gates , Did a back pressure test and had over 20 psi of back pressure the motor was also forged bottom , piping resturections and motor eating pound of air yoou feed it , I move my turbos to right off manifold an now get 23pis if i need it . Have a small vid of the boost and back pressure , new here do not know how to link it .
