440ci Z06, Ebay "PTK" kit; some results, some questions.
11-12-2008, 08:18 AM
#41
Tc76's WOOOT. I would bet the back half of those turbos are small causing some real back pressure with that 440. I've seen the same thing with a 408 and GT30's (or 28's can't remember now). Bad *** until 4500 rpm, then it falls on its face.
Oh yeah, the real problem is you have a mustang guy working on your vet. Those guys don't know how to work on cars with real power. haha.
Oh yeah, the real problem is you have a mustang guy working on your vet. Those guys don't know how to work on cars with real power. haha.
11-14-2008, 10:38 AM
#47
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We redid the waste gate reference lines into the manifold, the boost is holding more steady now.....still goes up and down close to 1psi but is holding boost to redline. The tuner has been slowly working away at it, just small steps at a time. Last pull was 800rwhp and 9xxtq still on 8#springs. David has built himself one hellava car!
11-14-2008, 11:26 AM
#48
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Now if they eventually come out with a big twin screw that fits under a stock C5 hood, I'd be fighting temptation big time.. We'll see in 09 
BTW, your graph looked similar to mine when I had the turbo's which the kit originally came with, I believe they were 44's, on my 408. Moved to 66's and you could almost feel the motor breath much more freely.
EDIT: Just read the latest posts and congrats! It sounds like it's running pretty damn good now!!!
Last edited by AVB; 12-03-2008 at 12:57 AM.
11-15-2008, 05:38 PM
#51
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yeah you need the two separate wg's because each one controls just one turbo having one would only regulate a singe turbo letting the other get away
11-15-2008, 06:20 PM
#52
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The turbo chargers are not to small. How ever, back pressure could be an issue. If the turbine housing A/R size is to small, or the exhaust diameter is to small, it may cause the power gains to fall off in the high RPM. Another factor you may not have considered was cam and intake manifold choice. This can also effect your power curve.
11-15-2008, 08:54 PM
#53
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Update UPDATE
Well, for the most part, the boost tapering off has been fixed. The wastegates are now referenced from the intake manifold.
.68 A/R hotside. As xLBx and others have said, this quite possibly could be my limiting factor. Definitely need to upgrade to at least a .96 Perhaps even larger. Vendors?
20 deg timing up top.
AFRs around 11.1
CAM: 235/230 .598"/.594" 114 LSA
L76 intake manifold
Well, for the most part, the boost tapering off has been fixed. The wastegates are now referenced from the intake manifold.
.68 A/R hotside. As xLBx and others have said, this quite possibly could be my limiting factor. Definitely need to upgrade to at least a .96 Perhaps even larger. Vendors?
20 deg timing up top.
AFRs around 11.1
CAM: 235/230 .598"/.594" 114 LSA
L76 intake manifold
11-15-2008, 11:43 PM
#55
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68 A/R T04 turbine housings are not that small. I would move upto .82 A/R housing and atleast 3" exhaust. What size muffler are you using ?
Don't be shy next time you choose a turbo cam.
Don't be shy next time you choose a turbo cam.
11-16-2008, 04:46 AM
#56
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LME spec'd the cam when they did the build.
