c5zJoe

Went to the track for the first time with my 408ci c5z that I recently purchased. First pass I spun like crazy. Second pass I slipped the clutch a tad too much. 3rd try SNAP, broke the outer cv I think. The car is also on a 28'' nt05r (i think the radial might be the problem, not as forgiving as a slick) and has a RPM built trans and diff. So do I purchase another oem c5z axle and buy a 16'' rear ccw set up or buy DSS 1000hp axle kit. Then buy ccw drag pack later on. both options will be around same price.

493lszosix

I would do the c5z axle over the stronger ones, I would much rather have the axle be the weak link since their easier to replace than the diff and the ccw's with a bias ply would be easier on it also

ForceFedC5

Been there, done that!

Contact Jeremy from RPM, he'll set you in the best-bang-for-the-buck option. He can also source GM parts as well, so he might be able to save you some $

c5zJoe

Even with an Rpm Stage 4 diff? I know anything can happen. I keep going back and forth on this haha. I would think the diff would hold up to my power level. Maybe it was a freak thing snapping the axle, I was told they been 8.70s.

0Jeremy@RPMTransmissions

Normally the C5Z06 axles work very well. Ive had quite a few customers go really fast with stick shift cars on them. But I'll be honest. The only time I ever broke my C5 at the drag strip I was on a drag radial. Once I switched to a bias ply all my breakage went away.

What rear gear is in the car now? A 28" tall tires puts a lot of stress on the driveline.

This is the first clean pass with my 430ci LS7 in the car. It ended up going 10.3X@138mph.

This is with the heads/cam LS6.

c5zJoe

The car came with the 28 when I bought it, I was told it had a 4.10 in it. It does seem like I have to shift into 4th 100-150 feet before the finish. But its hard to tell since i did not get a clean pass in.

0Jeremy@RPMTransmissions

The car would perform much better with a 26" bias ply on it.

c5zJoe

I think I will just buy another oem c5z axle and do a 16" bias ply set up and see what happens would hate to break again at the track since I don't always have the option to trailer the car. I also have a MSD 2 step laying around from my old car. When you launch on the slick do you do a fast controlled release? basically slip it just a little? Thanks!

0Jeremy@RPMTransmissions

No problem. That would be what I would do as well. The bias ply will be much more forgiving. Just make sure you get your CV axle from GM! Not a parts store. The parts store axles are garbage. I just had a customer put a set in his auto swapped C6 Z06 and one failed with 1.5 60ft times.

As for the launch method I would drive the car into the pre-stage beams, then bring the rpm up to my desired launch rpm. Then I would slowly release the clutch till the car starts to creep into the stage beams. Then I would press the clutch just enough to get the car to stop rolling. Then I would release the clutch quickly but allowing my foot to stay on the pedal while applying throttle. This prevented shocking the driveline and achived low 1.4 60ft times.

C5 Pete

Jeremy has some good advice here.

Stick cars and radials don't play well together.

A 26" bias tire would very likely work better for you, but you should really run with skinnys up front if you have a bias tire in the back.

As far as axles go, I've been 1.27 to the 60' on an OEM axle. I know others have been 1.20.

Sometimes you can find them used on here, or at a salvage yard vs buying new from GM.

I carry an extra one to the track just in case. Less than 45 minutes to change out vs repairing a diff.

Best of success to you!