Danger of helical diff on RWD cars
 

Looking at replacing my vlsd with an aftermarket diff and I usually run on mountain roads with tight turns.Deciding between quaife and wavetrac which are both torque sensing / helical diffs. Didnt want to go clutch type diff as i hear they induce understeer at tight corners more than torsen unless you force them to break traction for the purpose of drifting

As might know torsen diff has cornering speed advantage compared to open diff becos it sends torque to the outside wheel when cornering as opposed to open diff where torque is not being sent to either wheel

My question is whether torsen diff could cause snap oversteer if not being more careful with throttle? As seen for example cars with torsen diffs like s2ks, mustang and those newer cars with E diffs which act bit like torque sensing have nose dive accidents during cornering. With Wavetrac the risk is even larger because torque doesnt get cut at decel which imo sounds really dangerous to me especially when weight transitions to front during braking.

As far as i understand clutch types send torque to both wheels during cornering which is less dangerous becos it wont nose dive as the inside wheel has torque to push the car out during cornering?

https://youtu.be/wMZJ1E6BI0c

Here is a video of a crash with a supra vs ae86 which some of you migjt have seen (driver over corrected but beside the point). An example of a nose dive during corner exit that i am most afraid, seems to be a helical diff as only left outside wheel is pushing the car to the inner wall on the right? Would a clutch lsd induce such effect despite ppl say they give confidence at corner exits?

Can anyone who had installed torsen diff and been on autocross or track days give advice ? And for those who have clutch type is understeer very noticable at tight corners?

They both types send torque to both wheels. That video is most likely showing lift off oversteer then any specific differential issue, but it's hard to tell anything from it really. Those nose dive accidents are driver error of applying too much power too early in a rear drive car not the type of differential.

Helical, very linear engagement and predictable. No adjustment to engagement what you get from the mfg is it. Low noise compared to clutch type. Little to no maintenance.

Clutch, adjustable engagement to suit every event. You want a quick lock up you can set it, less aggressive you can set that too. It is noisy especially with low speed cornering. Regular maintenance needed, fluid changes, clutch changes. Not really an issue if you constantly taking it apart to adjust it.

https://www.kmpdrivetrain.com/differ...-differential/

I have the OS Giken. It's been seamless. Can't tell it's in the diff. It's quite. But you have to use the OS Giken gear lube with it. Mine is set to 1.5 way and 75% lock up. The oversteer and understeer is chassis set up.

I had a Detroit Locker in one vehicle. THAT would cause oversteer and understeer with the gas pedal. Let off the gas mid turn and it would pull the front into the turn. Give it gas and it would push the front. And it was really noisy. It would bang and clang when it released and locked up.

A helical diff isn't dangerous. Only the driver.

In terms of diff, I thought the under/oversteer characteristics is controlled by the amount and immediacy of lock during acceleration and deceleration....and not the type of diff....?

I got a good laugh out of that video. Somebody doesn't know how to drive. Complete driver error. What was the moron doing pushing that hard on the street anyways. That was just stupid. Play stupid games win stupid prizes.

First of do a little research and reading about the companies and their products. They both have done and still do diffs for Motorsports at the highest level. I ran a Wavetrac for five years on the street and track without issue and regardless of diff it makes you car way more predictable in over steer and understeer situations than an open diff. That is why you want to upgrade because of the way tq is applied to the rear wheels in the case of our cars.

The idiot in video simply ran out of talent and from the beginning all of us could predict the outcome. What happened to the driver is what is known as lift off over steer. He charges in with too much acceleration and then slams on the brakes causing his car to nose dive. Then as he is turning in he lifts off the brake and the weight on the nose is gone and the front end loses grip and the rear end gains grip...game over snap over steer engaged. There not one thing in that video or the comments you make have to do with a diff causing a car to over steer or under steer. That incident is all about physics and the driver flunked the course.

If you want to get a helical diff I recommend Wavetrac because of its locking characteristics when one wheel leaves the surface or that load being lifted from one tire. That said Quaife is a solid diff as well. Don't let canyon runners or people that don't have a clue about real world applications of products that thousands use in extreme situations as a norm provide you with advice. I am glad you found us here because there are no stupid questions, just stupid people. Don't be that guy!

Sent from my SM-G965U using Tapatalk

Finally got to watch that video. That was just a lack of talent. Pure driver error. :shakes head: The rear started to drift. He lifted. The rear got a bit of traction and wiped it to the other side. With the front wheels pointed right into the guard rail. His bucket of luck ran out, and his bucket of experience is still empty.

An open diff will be the safest option :rolleyes:

:inoutroflpuke:

A one wheel peeler. :driving:

More like the dangers of driving at the limits on a public road with zero runoff.

Chassis behavior is attributed to suspension setup. While I find a clutch type diff to be more predictable maintaining a slide, a helical is just fine for correcting a slide.-

In the linked potato video, it looks like bad driver input.

Danger of *being a smoothbrain