Torque steer and LSD

[energie]

I'm curious about torque steer on the S and JCW models. First, do you experience torque steer in any situations? If so, does the LSD option reduce torque steer on the mini? Thanks.

[ScottinBend]

The torque steer is an issue on the new 07+ MINI's and the LSD will not do much to eliminate it.

[mkaresh]

Best bet is always to check this out for yourself, though you might have trouble finding an LSD-equipped MINI to test drive. Perceptions of torque steer vary.

One thing that should help torque steer is stiffer springs, so the sport suspension should help. The greater the angle of the halfshafts under hard acceleration, the greater torque steer will be.

[ScottinBend]

Axel angle has very little effect on torque steer. The main culprit is the use of unequal length axels, which the new gen MINI have and the olders ones don't.

[mkaresh]

As I understand it, it's the combination of the two that's the killer. The problem with unequal length halfshafts is that the farther they get from horizontal, the more unequal the angles of the two halfshafts get, and these unequal angles are the source of the torque steer.

If the halfshafts are horizontal, their relative lengths are irrelevant.

Interesting that the halfshafts were equal length on the previous generation MINI, but not on the new one. I'd love to know how that decision was made.

[ScottinBend]

The angle has very little to do with it. Most FWD cars actually come with a solid half shaft and a hollow one to try and compensate for the torque. The first gen MINI's were designed to have equal length axles whereas the new ones weren't, the tranny isn't designed properly for it.

[mkaresh]

I've never looked far into the causes of torque steer. Now I find that a few minutes of looking around barely scratches the surface. A couple of interesting things to read:

http://www.eng-tips.com/viewthread.cfm?qid=136600&page=1

http://www.sportcompactcarweb.com/editors/technobabble/9909scc_technobabble/index.html

It does appear that halfshaft angle is one of a number of critical variables. At least Nissan thinks so:

http://www.nissannews.com/newsrelease.do?id=27&mid=124

The relevant section:

"New suspension geometry, shock absorbers with rebound springs, engine placement that is lower in the subframe and equal-length half-shafts that have equal angles and are more parallel to the ground all help to virtually eliminate torque steer."

There are clearly so many variables involved that it's not a matter of one factor being the true one and the others being incorrect.