JMURDOCK20

right! when i saw nigel post the picture of the vette on a role back it was heartbreaking

bmfvette

Were you able to look at any of the tunes?

realcanuk

If you're asking me, no. Haven't seen anything from those that broke.

CI GS

I would also like to see your comments on those, if you get an opportunity to look at any of them.

C5 Pete

It seems you guys are pretty focused on the tuning as the cause of failure. I'm not saying you're wrong, or that it can't be. But, from what I've seen and experienced, the pattern goes like this.

Ears break.
output shaft breaks
case breaks.

A brace will (should) help tremendously to stop the rotation of the diff.

Managing the tq output can also help to reduce the rotation of the diff.

For what it's worth, I have a TH400 in my car mated to the C6 diff. Multiple trans brake launches in the low 1.3 60' and foot brake launches into the 1.2s and it's holding together fine. Of course, I have a 2.48 1st gear. What does the 6L80 have?

Good luck with your repairs fellas.

subfloor@centurytrans

There's ABSOLUTELY nothing whatsoever in the tune that could have caused this. If my somebody put a gun to my head and forced me to try and tune a car specifically to have something like this happen it simply can't be done.

realcanuk

I'm not suggesting it fully the fault of the tune. I am just thinking that a harder shift could contribute though.

I agree its more related to stress on the case by not having a brace and/or good mounts.

Good thing you made us those braces.......

bmfvette

It was stated earlier in the thread that it was due to flex of the case and the intermediate shaft breaking. I don't think anybody thinks you can tune to break the ears or the case.

The tune came up during the torque management discussion.

The_Nigel

Little update. I got the car running again yesterday and I've put about 40 miles on it. It's crazy how fast the car shifts now, even under normal driving. I've done some hits in 3rd in manual mode and everything seems great so far.

I did modify my trans brace to work with the z06 diff and I welded the ears back on the Z06 diff.

Just gotta figure out why boost is dropping past 6k. I can't fit a boost leak checker between the blower inlet and radiator so I will pull a hotside pipe off and pressurize the system and I will probably change the belt too if that doesn't show anything. Even making 16psi by 6k and falling to 13psi by 7k the car is still pulling super hard so I can't wait to feel it making the boost it should.

The_Nigel

Was able to adjust my tensioner better and she's good now. made 18psi peak and right near 7k with the dongle on and a turbo guard on the end (air filter won't fit with my intercooler). Let it cool for 5-10 mins and remove dongle and did a pull and picked up 3psi and almost 80whp. All on pump/meth. I'll post another thread with numbers and more details soon. Going to the track again this Saturday.

I left the intake on for the street and have done a few 3-4 hits and the trans feels great.

realcanuk

Great news. What did you end up doing to the trans ? Who built and tuned it ?

The_Nigel

Myself and a good friend who works at a Chevrolet dealer (has all the special tools). Had to order 2 different snap rings to get the proper clutch pack thickness but that was no biggie.

I got the trans tune from Century since I trust them to know what their stuff likes. I'll just tweak shift points as needed.