[95 imp]

Originally Posted by jeep_junkie

Welp, life is expensive at 930 hp.

This little factoid made me El Oh El.

[ocautomotive]

Originally Posted by oldman

There are two non-related issues.
1) The input shaft failure is related to torque at the flywheel, being transmitted to the trans. In the higher gears, where there is a combination of traction and less to even negative torque multiplication (5th and 6th) the max torque is being transmitted to the input shaft. This is especially true for tightly spun smaller PD type superchargers. The failure point probably started in one of the spline base and slowly worked its way into the shaft. The type of cyclic twisting failure is NOT unusual.

2) Trans strength overall is the ratio between the gears. This is due to the fixed distance between the main shaft and the countershaft, for first gear to get the ratio one gear has to be BIG and the other small, the smaller gear also has drastically less lever arm to its associated shaft, combined with less teeth contact area (smaller diameter). Hence it is easy to see that the larger the 1st gear ratio the weaker the trans, it is a basic physics issue. To make the trans stronger one has to decrease this ratio (obviouse for the loading chart alread posted). Sure diffeent alloys, heat / cold treatment, surface hardening etc can all help, but I'm trying to illustrate basic design here. So most transmission failures should be in 1st gear.

Sure no doubt about it, the more traction the better the clutch, the more potential for trans failure either 1st or input shaft / output shaft. I had autos in most of my V8 cars so I'm unfamilar with the T56 and its siblings. So I don't know the common failure points. I would assume there are input shafts with more splines that are at least surface harden at the splines. I'm also sure there are ways to make sure 1st gear does not blow up (either less ratio replacemnt or a performace intem of some sort).

Thank you for the info

[JROC]

That's a bummer, but 930 HP. (I'd assume WHP?)

Does GM still use a 26 spline input shaft? Maybe you could convert to a 31 spline shaft. I think that's what the Vipers used to use.?.? Obviously on the old T56 it was Viper Spec T56 > all other OEM T56's. I'm guessing it was/is the same with the TR6060?