LS4 Performance - 7000+??
11-18-2008, 10:19 AM
Hey everyone, bored at work....I watched Mixerda's dyno run compilaiton video again last night, and it got me thinking.
A few summers ago I went to Road America for the Brian Redman Int. Comp. and they had 3 or 4 really cool old camaro's with high revving 327 small blocks.
Mixerda's Impy is shifting around 6K in his video...but there is alot more potential there, if you listen to the engine it sounds like it is just starting to make power when his car hits the shift point.
I know long winded....do you think it would be possible if you take out DOD/AFM, beef up the bottom end and the top end, and get these engines to zip up to or beyond 7K???
I know it would be expensive, and a turbo is cheaper, but an N/A high rev engine just sounds soooo mean....
What do you guys think????
11-18-2008, 11:51 AM
not sure you could probably get these to rev as high as any of those racing vettes though with enough work
11-18-2008, 11:57 AM
Basically like you said, you can do anything with the cash. It might not be economical, but it can be done. There a lot of other routes I'd go down with my car before that one, but if you want to do it, go for.
11-18-2008, 04:34 PM
I would say the engine would take it just fine. Put some decent valve springs on it and a proper cam, the fuel and ignition system should be more than sufficiant. The only downfall would be the accessory drives and the transmission. You would be eating waterpumps, power-steering pumps, alternators, etc. Maybe with some big time underdrive pulleys you could get away with it, but the transmission is NOT gonna like spinning that high with higher than stock input power.
11-18-2008, 06:57 PM
I've read somewhere that the sinter forged rods we have are some of the strongest connecting rods GM put in a stock engine, so they should be good for 7K.
No one seems to know the max rpm the dod lifters can take. Since I upgraded to the Comp 918 springs, I've bumped the redline to 6300 without any apparent adverse effects the few times its been taken to redline. Scan data shows that the engine is not breathing too well at that speed:
Dynamic cylinder air charge drops 12.5 % between 4800 and 6200 rpm and manifold pressure @WOT drops by 5kPa between 3600 and 6200 RPM - don't know yet whether that's due to the intake manifold restriction or the mostly stock airbox.
11-20-2008, 05:47 AM
yea that was because my dyno operator didn't know how to tune the damn car right :ripped: j/k he knew more than I did but didn't know how to get the TCM set up properly. He had the ECM set up properly but because the TCM said max rpm before upshift was 6100 would always force that upshift at the 6100 mark, that's where my peek power always cut off at. Since then I've gone in and tweaked the tune a bit 1st shifts at 6750, 2nd 6500, 3rd I have set down to 5500 but I really haven't had a chance to take it out there since I've only done one run that was above the 130's since the cam swap. I'll prob raise the 3rd shift point to 5750-6K when it's all said and done.
No ill tranny effects to date yet, but with that sad I know I'm going to kill this transmission it's just a matter of time. Oddly enough I've been breaking the drag radials in before I get some track time on the tires and transmission has held up thus far, we'll see what happens at the track this weekend.
edit: I would make a new vid of the shift points ect but my brother borrowed my camera and has seemed to of lost it. If he doesn't find it by this weekend I'll just buy another camera when I go down to the track. Oh a couple of us are meeting up on Sunday Nov 23rd down in Houston at the houston race way(baytown track), so if anyone local wants to come more than welcome to.
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