ealoken

Hi guys, what whp and torque break the S2 gearbox?

Im planing on 500 whp this year, but when does it break, and in what gear?

I have read 600 whp on a mustang dyno, but i did not get the TQ numbers.

I know that 1st and 2nd is kind a weak, but what about 3,4, and 5th?

Thanks.

Erik

MAGK944

ealoken

Sorry for that..

arthropraxis

My car spun third gear with 327 WHP and a little more torque. A friend was driving it sidestepped the clutch and shifting very quick. He was used to a straight cut gears. I don't think it is the power as much as a combination of power, shifting like an idiot and sticky tires. If the tires don't spin a little to relieve the stress either the transaxle or the CV joints are going to break. I like the tires to be the fuse.

PaulD_944S2

S2 first & second gears are shot peen hardened, same as the turbo.
But you can break anything if you try hard enough.

rlm328

You will probably fail the half shafts before you fail the transmission.

Dave W.

I ruined a diff bearing from too much wheel hop. I also have sticky street tires and approx 400 lb.-ft. of torque. Heat can also kill the trans, so if you do hard events with thin oil and no trans cooler you can expect the trans to wear down faster.

ealoken

I have a plan there, motorsport CW and new shafts for motorsport.

ealoken

The gearbox is cooled, i have two coolers for that.

rlm328

You want a cheap weak link. The half shafts are cheap compared to a transaxle and can be changed at the track. I am pushing over 450 ft-lbs at the wheel with 17 psi boost. But I am using a 951 transaxle

ealoken

I have a friend that works at a drivetrain shop, they make shafts for drag and drifting, that can twist, that saves gearboxes and diffs.

Ill have to look into this later, when im done with the rest of the build.

Thanks for input 450 is a lot

Tom M'Guinn

I blew up 2nd gear on a standard 951 transaxle with about 450/475rwhp/t (dynojet). Kevin Gross built me a replacement with limited slip and hardened 1st and 2nd, and it's been holding, including after running it at about 500/500rwhp/t for a while (on the street, not track). Reasonably new CV joints shattered at 500/500, so I upgraded those and filled-in the mount. Then there's the clutch...

ealoken

Ok, so 500/500 is a nice figure. Sachs delivered my new clutch, and it`s rated to 650nm ( aprox 500 ft )

Tom M'Guinn

What clutch is that? Is this a street car or dedicated track car?

ealoken