I have searched and can't find any info on the T56, How fast are people going with it, I fig low 10's and i saw 1 high 9sec..

but would be the average
at what point will it break and how much to fix$$$$

 

Taner was using the T56 in his lt1 running high 9s/low 10s for a while. He broke (3?) output shafts before he went to the viper. The viper output shaft is ~$274 but requires a lot of work to make it work. There are two shops that I would trust doing it, and one is www.ddracing.com which did taners. You can expect an out the door price of $800, but this doesn't guarantee you from breaking an input shaft or a gear. Sure hope you have a good driveshaft/rear end to go with that too.

 

Mine didn't break in a 4,000lb car going low 10's,

Rich

 

im going on output shaft #3, and i think the place that rodriguis meant was www.ddperformance.com, they are based out of wixom, michigan and is owned/ran by donny walsh senior and junior. they do the baddest t56's around. their viper ouput shaft conversion is 799 plus a 250 core for the tail housing. it is a very worth while investment and even includes the yoke for your driveshaft. (you will need a bigger diameter d/s too because stock ones break)

you can go 10's on a stock t56 but its only time before it will blow. and im speaking from personal experiance.

hope this helped

 

A couple of more comments. The strongest T56 currently available is the unit from G-Force. However, if you want the "top of the line" with upgraded input and output shafts, gears, synchros, and shift forks (basically, all of the major parts) it will cost close to $5,000. You can run a stocker very hard though. I have never heard of one breaking on a street car. The breakage is always related to track use: sticky tires, prepped surface, clutch drop starts. It isn't hp per se but hp + traction that's the problem.

Rich

 

I was stripping the gears off the input shaft/countershaft by rolling on the gas in 3rd on the street. (stock T56)

My friend Dan with his 900rwhp Cobra was doing the exact same thing (stock T56).


I had G-force do my T56, which included new 1st-4th gears and input shaft, triple cone synchro conversion, 4340 30-spline output shaft. (It was a little under 4k) We are a dealer for G-force if anyone is looking for one.

So far this trans is taking everything I can throw at it.

I've made tons of passes on it, and have powershifted it into the 9's 4 times now.

Yesterday it ran 1.54 60ft, 9.77 @ 149.4 never lifting off the gas. Rolled it up on the scales right after the run and it was 3,750lbs.

The only downside to this trans, is 1st-3rd gears have some noticeable gear whine. 4th-6th are quiet.