Dyno sheets...

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Jul 9, 2007 | 12:27 PM

dj_stylzpgh/GXP05

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From: Pittsburgh, Pa.

Dyno sheets...

First, check out the Magnaflow Dynojet before and after their catback system. Baseline looks to be 220 or better at the wheels

Best quarter was 13.7@101.

Jul 9, 2007 | 05:24 PM

06 SS

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ok, what I see is about a 15 horse gain in the first one (with a base of around 235 horses and ignoring the obvious false spike. Now assuming the next few are of the second gear run, they are about what I would expect, although it does seem that you might be running into valve float near the top, the LS1 springs are junk, but I would still expect them to run to redline at the 22k miles (or whatever it was you had). The bottom two runs look like they were aborted early, 400 RPM or so before expected peak power. They were also looking a bit unsteady at the top end as well. At a guess, your are losing torque due to valve float and unable to pull high enough to see peak power with the cam and the LS6 heads. The trouble is magnified in 3rd gear, more load on the engine and all.

If it were me, I would be slapping on some decent valve springs, I think it is just a good general upgrade (although it might more properly be called maintanence in the LS4 if the springs went bad that fast) Not saying that is your trouble for sure, but springs are cheap.

Jul 9, 2007 | 07:05 PM

eddiemoney

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Want to drive to Iowa and put in springs for me ...

Jul 11, 2007 | 03:53 AM

DavidGXP

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Drag racing is so much more fun. Now get to the track!

Jul 13, 2007 | 08:56 PM

johnh

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220 whp for a stock GXP?!

My GTP dyno'd 219 whp 100% stock! I'd expect a stock GXP should be much higher...give 260 crank vs. 303 crank.

Jul 14, 2007 | 05:23 PM

BuffaloSS

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Everyone else has been showing 240-250whp on their dynos...not sure what's up with this here...but i cannot read a dyno for chit so i'll keep my mouth shut from here on out

Jul 15, 2007 | 10:09 AM

07ImpalaSS

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Hey guys, I am new here but I have been browsing for a few weeks now. Just to chime in here from what I have read on the forums here, the 303hp LS4 dynos around 245hp to the wheels. I recall someone said figure an average of a 19% drive train horse power loss to the wheels.

Anyways, hi guys!

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