HardcoreABN

Ok, so I am going to the track Sunday to see how she does with her current build. On the rollers it made (rather disappointingly) 475/450. HP peaked at 5750 and stayed about the same until almost 6500. M6 with 3.42 gears. My question is what should I be looking at for shift points? I am not going to be launching very hard, just want to get under 2.0 60' lol. I will be running 26x11.5 17" MT ET Street Bias Ply rears and MH skinnies up front.

I am hoping to eventually get down to a 1.7 60' after I rebuild my 3 rib diff with 3.90 gears and C6 Z06 internals and get an ECS trans/diff brace. I am shooting for 10.5 on motor, but I know I won't get there until I find my missing hp and get over 500rwhp.

dennis50nj

you want your shift extension to be as close to 5750 as possible for each gear

HardcoreABN

thanks. Hopefully I can figure out why I am peaking at such a low RPM so I can get more out of it lol.

dennis50nj

what intake and cold air, sounds like a tune problem whats the new build

HardcoreABN

I dunno about the tune, it has GREAT street manners though with no issues with low speed/rpm driveability. I have been told the problem could be anything from the headers/exhaust being too small to the lifters/pushrods. You are the first to mention it could be the tune.

Specs on the engine:

2000 Corvette Z51, M6 T56, 3.42 3 rib diff

402 LS2 (4.005" x 4.0")
- Callies Compstar crank/rods
- Wiseco pistons/rings, -8cc dish
- GMPP CNC LS3 heads with Comp Cams 921 springs (installed height verified), milled .036"
- Cometic 4.085" .045" thickness head gaskets
- 11.5:1 or so compression
- Comp Cams 875 lifters with (I believe- I can't find my notebook) .020" preload
- Comp Cams 7795-16 Hi-Tech pushrods, 7.375" measured for .020" preload
- Comp Cams 235/250 .621/.595 115+4 spec'd by Martin @ Tick
- LS3 intake/LS2 throttle body
- return style fuel system conversion
- Holley billet rails
- Aeromotive 13101 regulator set at 58psi plumbed after the fuel rails
- all Fragola PTFE braided stainless lines
- stock GM fuel supply line
- 60# Deka injectors
- KB BAP set to turn on at 4" of vacuum
- Melling 10296 oil pump
- Edelbrock Victor water pump
- under drive pulley
- MSD plug wires
- NGK TR55 plugs
- LS7 MAF in a 4" housing mounted at the throttle body
- Vararam
- Comp Cams billet tensioner
- ARP rod bolts, head studs, and main studs
- AIR delete
- LG Motorsports Street Series 1 3/4 headers 3" collector
- Corsa dual 2.5" Tigershark exhaust
- no cats

C5 Pete

Good luck tomorrow.

It certainly seems something's off with your setup. A 402 with ls3 heads should make more than that.

HardcoreABN

put 6 passes down, only 1 was fairly clean....best time was a 11.79 @ 121.46 1.769 60'. Still picking up 30+ on the back half - 1/8 7.70 @ 91.99. I can feel it has more in it, as I am still bogging down after launching. I just don't want to launch it like the tires want until I rebuild the diff with all C6 Z06 parts, 3.90 gears, and put an ECS trans/diff brace on it. Was also hot as **** today too.

Danny Richie

If it were me I'd hit 6500 on the one/two shift to keep you further up in your power band when it drops to second. You might also want to try the rest of your shifts in the 6200 range or higher.

A little lower gear and better launch and you'll be right on down there where it should be.

HardcoreABN

Soon as I get paid for the 2 trans jobs in my shop now I will be ordering parts to put all C6 Z06 internals and a 3.90 in my 3rib. I'm considering 300m output shafts instead of the C6 Z06 output shafts but I dunno. Then once I get an ECS trans/diff brace - or have 1 fabbed up - then I will actually be able to launch it. I know she has a LOT better 60' in it, going to shoot for 1.5x - 1.65 60' times.

C5 Pete

While everyone's experience is different, I'd vote for C6Z shafts.

I've broken the 300M shaft once, and twisted the spline on another one. I've never broken a C6Z shaft. I have friends that have had the same results.

Good luck with your goals!

robz

Take your time and figure out the car.
There may be a typo above. You said 1.46 60'
They sell stronger shafts now than old 300m
goodluck

HardcoreABN

yea, I meant 1.769 60' lol