How much hp and torque can a 115mm diff take,

 

Thanks

115 mm = 4 1/2 inches.  Not very big.  Most of the estimates you'll find are based on what people have seen break a few diffs, or what they've seen them handle without breaking.  I doubt that anyone here has run a 115 mm diff.

The rear end I am referring to is a180 out of a Z car.  R180 came in 110mm and 115 inner diameter detentions of the ring gear 

I run one in my 240 race car and depending on the configuration (I run it as either a 240 or a 280) I am making 245@crank with the L24 and 325@crank with the L28 on 110 fuel.

 

The R180 (115mm) has 4:38 gears and a Quaife. No issues to speak of.

gnosez

What kind of torque are you making on your motors? It was my understanding that torque was what kills drivetrains...

Let's just say I might have run an engine that was not legal which had over 350hp@crank and over 300 lbs of torque. No issues. This is a road race car so no launches like in a drag strip car.

 

I also run a 4:44 LSD R190 which is a heavy bugger.

Thanks

_{Thanks gnosez for the information.  Do you know how much race time you have on the 180?}

I say just under 30 hrs

An open two pinion R180 can't handle much torque and will self destruct if you do a lot of one wheel burnouts.  A R180 with a four pinion carrier, or a good LSD (Quaife, OS Giken, Nissan Motorsports, etc.) can handle about 275 ft. lbs. if you run a synthetic fluid like Redline 75W-140 and change it often.

Edited November 23, 201510 yr by John Coffey

Quaife and Redline changed out after every race weekend just like John said.

Normal torque for the L24 and L28 are right in the 210-270 range respectively depending on set-up (head, pistons, etc.).

Consider shock loadings too, like clutch dumping. They make a lot of difference.