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Help! More Hp and Slower E.T's!

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Old 01-10-2010, 03:19 PM
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Default Help! More Hp and Slower E.T's!

Help me out fellas. My old setup was a stock LS6 block and internals, Trick Flow 215 heads milled to 60cc, a 228/234 112+4 lsa cam, a Yank 3600 with 3.42's. The car was strong and ran 11.6 @ 121 in the1/4. My new setup is the similar. Changes are lighter forged pistons and rods with stock crank, same Trick Flow heads but milled to 59cc, now have 12:1cr, and a new cam: 236/243 112+4 lsa that I thought would be better for the higher compression. Still have the 3600 stall and 3.42's. With this setup I ran a 12.2 @ 113! WTF. On the freeway it feels way quicker and north of 100mph its a beast. It really makes power up in the rpm range but at the track with a 2200rpm launch it was ******* it. The launches didnt feel as hard as before with the old setup and the 113mph bothers me. Im think the 3.42s arent enough gear for me to get in my powerband and launch the car hard enough. At 2200rpm it was creeping at the line. Any suggestion guys? Should I look at something else or does the car need a lot more gear, like 4.11's, or more stall for that cam? I thought my mph would at least be higher. Help!

BTW, new setup is a result of blowing piston #7 on old motor.
Old 01-10-2010, 08:31 PM
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Originally Posted by jim1450
8 mph slower with the new combo, looks like less power.
Did you dyno tune it?
Its tuned but not on the dyno. I was thinking of getting it dynoed this month. Im thinking those 3.42s arent enough gear to get it into its power band especially off the line. But on the road at higher rpms its definately quicker than before so I should be making more hp... just way up top.
Old 01-10-2010, 09:13 PM
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You lost 8 mph. Big hp loss. How do you know it makes power at a higher rpm? Either its a tuning issue or a mechanical issue with the new set up. Get to a dyno and see.
Old 01-11-2010, 07:17 PM
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get it on the dyno before you start thinking you need to change anything. its more than liky the tune needs some work still for the 12 to 1 cr wow thats high is this a street car?
Old 01-13-2010, 08:02 AM
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Hey guys I was wondering, what effects torque management would have on a run if it were still present in the ecu? The car didnt want to rev up and bogged on a burnout (attempt) the first time and it felt weak after the 2-3 shift, where TM takes timing out and a lot of it. All the symptoms the car had, it falling on its face, it feeling quicker on the street, seem to be signs that TM might still be active. It might have been overlooked by accident when I got the new ECU. Also I had to do a crank position relearn, I dont know if that effects the TM in any way. I'll have my tuner take a look. Have you guys heard of torque management doing something like this because Ive seen some graphs taken during 1/4mi runs and you can see it take a huge chunk of timing up top too. Just wondering....
Old 01-14-2010, 06:01 PM
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Something is WAY off for sure! Knock sensor? Something stupid. 8mph is serious.....
All 8 plugs and wires good? LOL. Get it to a good dyno and tuner. The new set up does need a bigger gear and converter...but it wouldn't slow down like that.
Old 01-15-2010, 11:04 AM
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Originally Posted by Chris05ssTruck
Something is WAY off for sure! Knock sensor? Something stupid. 8mph is serious.....
All 8 plugs and wires good? LOL. Get it to a good dyno and tuner. The new set up does need a bigger gear and converter...but it wouldn't slow down like that.
I agree. Ive been doing a lot of research on torque management, on how and when it pulls timing, and the car showed all the symptoms of TM kicking in. Im just waiting for my tuner to get his laptop back from the computer guy so he can look at the file in case we missed a table somewhere where it might still be active. Im also wondering if the crank position relearn test changed or affected anything. It felt like a different car so I know theres a glitch somewhere. No mechanical reason for it to have slowed down that much that I can think of. I know I need more gear and stall but it should have at least have had a higher mph even with a slower et.
Old 01-15-2010, 04:43 PM
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Car is tuned for 91oct so it only has 21 degrees of timing, plus at the track I ran 100oct just to be safe.

Good news though, tuner just called me saying it looks like there is a torque management table open in the ecu. He's going to zero it out plus raise the shift points. After we"ll run it with thewideband to check it. If all is well I"ll get it on the dyno next week and test on the 1/8mi track. Got my fingers crossed.
Old 01-16-2010, 06:06 AM
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You need to get on a dyno. With 12 to 1 compression, there's a really good chance it's knocking like crazy and pulling all the timing out.

You're probably gonna need a little race gas to get that to run right with good timing in it... so get it tuned in open loop so all the o2's are off, and add some leaded fuel, will make a HUGE difference in how it runs. I'm sure.

Other possible issues, you're blowing thru the converter, or like you said it takes forever to get in the powerband, but that I doubt. The 3.42 isn't the right gear for something like you're running, you really need a 4.10 or the like, but with a vette you're more limited, so converter choice, is going to be the next way to do something about it. Most likly you're going to need a 4400 rpm converter that is built for the power level, so it won't be too slippy @ the top end, but still stall high enough to get you up in the power immediately.
Old 01-18-2010, 04:36 PM
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Got some tuning done today. Torque management was still on so that got zeroed out, on all tables. We also added 2more dergrees of timing from 4-7000rpm and raised the shift points also to 7000rpms. I drove it a bit on the street and a few freeway miles but the car felt a lot more responsive and eager to revv up, even more than before. Its been raining so I havent gotten on it but as soon as I dries up I'll be out there testing it. Hoping to jump on the dyno soon too. Because of the rain we couldnt do some pulls on the street with the wideband so to be on the safe side we slightly increased the fuel on top for those few extra rpms on the higher shift. So far I did feel a difference so we'll see how it goes.




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