Diabolical!

If so, please give me a little info about what happened (HP, torque,type of tires, type of clutch, launch technique, etc.)

I'm considering buying a 26 spline input shaft from pro motion when I swap my clutch, but I'd like to gauge just how much abuse the stock 10 spline can handle before I fork over the big bucks for the 26 spline. I'm planning about 450 RWHP, so I'm hoping the 10 spline can handle a safe margin of more HP than that.

Thanks a lot guys.

Black05StangGT

Its going to have more to do with the torque and how well you can deliver the torque through the drive train that will cause the input shaft to snap...if you have a hard launch with some really sticky tires and you have a clutch that bites really hard...its going to snap easier than if you have more give at the tires and at the clutch...someone can correct me here, but from what I was reading our stock tremec is done after about 360 ft./lbs of torque, which would mean to me that the 10 spline should be included in saying it would be done right around 360 ft./lbs...in theoryit shouldbreak on a really high reving hard launch with sticky tires and a hard biting clutch, but thats all on paper, what actually happens at the track is a different story...although if you are going to look at upgrading your input shaft on your tranny, you might as well consider upgrading your axles and differential as well...and I see you've already purchased the 1 piece drive shaft, so you are already on your way to solidifying everything...

Diabolical!

Damn, that's not what I wanted to hear, lol. I know a guy with about 340 rear wheel ft. lbs. of torque who launches on slicks at 5500 RPMs with a specIII clutch, and hasn't broken anything yet, but I'm planning on making a lot more than that. To give you a better idea, here's my plan:

1.)Spec II clutch (Buying today or tomorrow, as soon as I decide what input shaft to go with.)

2.)Brenspeed's stage 4 saleen kit at about 460 rwhp (Buying in the coming months, as soon as I've finished prepping the car for it.)

3.)M/T ET Street 26x11.5x17 bias ply street slicks (Sitting in my garage on a spare set of rims. Already have several passes on them and damn do they hook!)

4.)Many hard track launches(This is why I need to decide on upgrading the input shaft.)

I know brenspeed runs the TR3650 on a lot of their boosted cars, but I haven't heard of them breaking any. I'm hoping the TR3650 stands up to a lot more abuse than Ford advertises (especially the input shaft, which seems to be tha weak link in most of the past mustangmanual transmissions.

ohnoesaz

I've only read of two S197s breaking theirs... Both were extreme cars well over 430HP/torque, probably towards 500.

So if you plan to go FI which your post above suggests, then yes you're definately in danger when running slicks and a hard catching clutch.

NA guys, like you for right now, are definately ok, even with slicks IMO.

Black05StangGT

Yeah as I said, what people are doing on track will definitely vary in results as to whats being shown on paper, but I say go big or go home, lol...get the shaft and do it right the first time, unless you plan on getting the TR 6061 or the like to replace the stocker...

ohnoesaz

Do you think the differential would break before the input shaft?

Stkjock

two things...... I have only heard of one breaking and it was high tq car... dk how high..... but at least 500rwhp

seems to be 400+ ft lbs is the breaking point... if you have a strong clutch and sticky tires

second... seems impossible to get a 26 spline from promotion (or that could be another source?).... guys have been waiting....and waiting and waiting...

Diabolical!

Well, I've decided. I talked to Dave at brenspeed today via e-mail. He told me that their '05 GT test car cuts 1.6 second 60 ft. times with a tight clutch and slicks on the stock 10 spline input shaft. If their test mule can handle it, then I'll stick with the 10 spline and hope for the best.

androdz

I haven't broken the imput shaft but I broke the syncro assembly once and I broke the 3rd gear pinion once also.

Andrew

429244

Search finds some old threads.
Diabolical,
Are you still using a TR-3650? If so, did you break the 10 spline input shaft yet?
Thanks.