1,049 whp, what's wrong with this curve?
04-09-2013, 03:41 PM
#1
Racer
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St. Jude Donor '14
1,049 whp, what's wrong with this curve?
Hello everyone,
I am posting these two dyno runs of my 2007 Z, one without meth and one with. I dont't think the drop of power past 6,200rpm is normal. I would like to know if the problem lies in the YSi spinning too fast and going way out of efficiency. I keep reading about over spinning the YSi to 80,000rpms and I am only spinning it to 63,400 at 6,200rpm and 71,000rpm at 7000rpm. I have enough fuel, 1,7/8 headers, stock mufflers.
At 7,000 rpm boost is 25psi
Your comments are appreciated. Thank you very much.
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I am posting these two dyno runs of my 2007 Z, one without meth and one with. I dont't think the drop of power past 6,200rpm is normal. I would like to know if the problem lies in the YSi spinning too fast and going way out of efficiency. I keep reading about over spinning the YSi to 80,000rpms and I am only spinning it to 63,400 at 6,200rpm and 71,000rpm at 7000rpm. I have enough fuel, 1,7/8 headers, stock mufflers.
At 7,000 rpm boost is 25psi
Your comments are appreciated. Thank you very much.
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04-09-2013, 04:02 PM
#3
Air fuel? I only ask because it appears that the meth pull carried a little further. That's about where the stock intakes peak though. A big cam will help it carry a little but not much as it's really dictated by the intake manifold.
04-09-2013, 04:06 PM
#4
Racer
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St. Jude Donor '14
I am just spraying a little meth to lower the IAT about 40degrees, if the meth stop working the engine will not suffer.
CR is 9.7; cam is a big one.
04-09-2013, 04:15 PM
#6
Former Vendor
.050"-.060" shim under the spring base to get the install height correct? if your running an aggressive ramp rate cam, with a taller ls7 install height, and add in 25 lbs of boost, you're going to run into issues...
04-09-2013, 04:25 PM
#11
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St. Jude Donor '14
what cam is in it? meaning what lobes ? factory ls7 heads ? what valves in the heads? you run a
.050"-.060" shim under the spring base to get the install height correct? if your running an aggressive ramp rate cam, with a taller ls7 install height, and add in 25 lbs of boost, you're going to run into issues...
.050"-.060" shim under the spring base to get the install height correct? if your running an aggressive ramp rate cam, with a taller ls7 install height, and add in 25 lbs of boost, you're going to run into issues...
The cam is a custom from EPS, LS7 heads, no shims. If I install shims, I'm going to have to change the spring, they would collapse.
04-09-2013, 04:28 PM
#13
Former Vendor
if the boost is still rising up i doubt it... EPS generally is spot on for the camshaft in boosted apps, so i bet the cam lobe is right, why do you have to swap the springs? without a shim your install height is going to roughly be 1.850ish on a stock ls7, if you throw in a .050"-.060" shim you'll be around 1.790-1.8" which is the install height the Patriot Extreme spring is rated for.... not understanding "the spring with collapse" comment..
Last edited by Cunningham Motorsports; 04-09-2013 at 04:37 PM.
04-09-2013, 04:29 PM
#14
Former Vendor
yeah i got you, but its not going to look like that, especially with a centri, it will just level out and taper off, not take a nose dive...
04-09-2013, 05:10 PM
#17
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St. Jude Donor '14
if the boost is still rising up i doubt it... EPS generally is spot on for the camshaft in boosted apps, so i bet the cam lobe is right, why do you have to swap the springs? without a shim your install height is going to roughly be 1.850ish on a stock ls7, if you throw in a .050"-.060" shim you'll be around 1.790-1.8" which is the install height the Patriot Extreme spring is rated for.... not understanding "the spring with collapse" comment..
04-09-2013, 05:14 PM
#19
