Chris Stewart

1) What's the best 60' you've launched?

2) Also how many times have you backed it up? (or close)

3) Is your stock rear still unbroken and all stock, or blown to pieces?

I see alot of post where the rear blew, but seems to be after adding a lower gearset. Just wondering how much abuse the stock rear will tolerate.

0euro@EFIAlchemy.com

1.60 Stock rear, only did it once



Here is the second launch lol

Chris Stewart

Oh man, BUMMER! I've cut a 1.60 once, I hope that wasn't the last one!!

The video comment says you broke a shaft. I have a hardened shaft on the driver side and DTE brace, but I still consider the rear stock. Maybe I should say diff...

0euro@EFIAlchemy.com

I broke the passenger side shaft, you know, the one that never breaks

Chris81

I've cut a ton of 1.78-1.80 60' on mine with everything stock except a set of 17 inch BFG DR's

Thats only going to the track a couple of times on DR's.. i'm confident it will go into the 1.60's this fall.

I have a DTE brace sitting in the floor, but i'm going to wait till early next year to put it on since i'm upgrading alot of other drivetrain parts as well.

highpockets

I have pics,as well as a pile of parts from a stock bottom end,NO power adder 04 Z that has gone through 4 output shafts.One each side on 3.42s and one each(incl a hardened long side ! ) on 3.90s ! the 3.90 rear had 3 passes total when we pulled it to inspect(wheel hop,killed them all) Since swapping to CCW drag pack he has gone from 2.0x or broken 60s to 1.7x 60s with NO other changes. Car seems to launch MUCH softer with these tires than the drag radials,wheel hop non-existant and 1-2 shift brings a quick screech instead of 75ft of rubber and tail wagging ! I built mine before I tried it so I cant give you any other input,I didnt want to trailer it home first time out !

PRE-Z06

1.74 completely stock, w/ multiple 1.7x...1.63 a couple times, w/ multiple 1.6x after only 4.10 gears(no hardened shafts or diff brace)...I've never popped/side-stepped the clutch either...don't let it dead hook or wheel hop, also run et streets to help absorb the shock

EGash

In my Silver 2000 A4 I cut many low 1.5x 60's on the stock rear. I think my best was a 1.52 This was on a stock 2.73 rear, with a 3600 stall converter, RPM level4, X3 cam, 150 Shot and bolt on's. It went 10.98@124 and 6.99@102 best 1/4 & 1/8 mile on that setup.

I never broke the rear end, but I did eventually break a stock output shaft on a later turbo setup. The rear will take a lot of abuse if you don't shock it too hard (i.e. with an M6) and don't wheel hop. I was running 17" MT ET Streets and ET Street Radials. Good luck!

AlwaysInBoost

not a bone stock rear here, I do have a DTE brace and their 300m output shaft on the driverside. That said I've cut multipal 1.4x 60's a drag pack with the best being a 1.410 and never had a breakage.

JDaniel

I guess we will see what mine does in a couple weeks. I have the 300M hardened halfshafts on both sides and 4.10 gears. Wish me luck! LOL

procs2v

1.60 a bunch of times. stock gear stock clutch. Once I put a new clutch and tried to get in the 1.55 range it broke a output shaft.

Here's a 1.61' pass. Headers, cai, tune, and a tire

http://www.youtube.com/watch?v=kn362bEBO-s

Rob98C5

I broke the same shaft (passenger side) at the same track, in the same lane even... it's breakable alright

highpockets

Looks/sounds like you slipped it of the line with very little tire spin at about 5K and ran with it ? Could you add details,I am trying to clean up my launch while holding the broken parts box in the empty form.

procs2v

100% right. 4500-5000rpm and ride the clutch out. On that run the 330 was off because it bogged after the 60'. I have learned to get on the gas quicker which made the e.t. drop alittle. I broke my rear when I got an after market clutch that did not allow it to slip. I was told at first that that 4500rpm was to high for a stock clutch, if I know then what I know now I could have went alot faster with only a tire/cai.

Chicago1

What do mean when you say "and a tire" stock tires or DR? Awesome launch man

procs2v

Mickey Thompson dr's

Chicago1

Very nice, what size and all that good info? What rims are you running these on?

procs2v

275/17's @about 17psi on stock z06 rims.

Ronnie55

Originally Posted by procs2v
1.60 a bunch of times. stock gear stock clutch. Once I put a new clutch and tried to get in the 1.55 range it broke a output shaft.

Here's a 1.61' pass. Headers, cai, tune, and a tire

http://www.youtube.com/watch?v=kn362bEBO-s

procs2v,
After being at the track on Friday for the first time, I am impressed, and inspired by that launch. I’ve got some work to do.
Ronnie

02402ramair

I have a long shaft and a DTE brace


over 30 1.5 60s
over 20 1.4 60s
5 or so 1.3s
best is a 1.35

I would say I have around 100 or so passes on this diff.
7000 rpm launches and the 1.3s are with a 100 shot out of the hole!

This was a brand new GM 3.42 unit that I started with. I put a 300m long shaft and a 4.10 gear set in. I tightened up the clutch packs also.

IMO the best way to keep a rear diff together is top run a slick (CCW drag pack) stage the car, let the clutch out to the point where it almost engages, push it in slightly, when the lights come down you don't side step, you let it out easy. I run a triple so it still grabs quick. A 28 inch tall tire on a 16 will absorb allot of the hit.

Launch technique will be the key