Mechanical LSD

[WAM]

Trying to decide between a clutch LSD (Cusco) and one of the Torsen types. Primary use is prepared class rallycross.

I spoke to Cligedy about the gear type he uses in autoX. Does anyone have any FiST experience with the Cusco or similar?

 

[skidro87]

I can't comment on the actual lsd yet but I bought an m-factory one as well because of the apparent lifetime warranty

 

[M-Sport fan]

I never even knew that the various Nippon clutch plate type diff manufacturers made their products for our app.

 

[WAM]

And I can't tell you that for sure. I think the shop I contacted deals regularly with Cusco. Maybe he's expecting something custom...maybe he's expecting to adapt something. Maybe he was wrong.

 

[stascom]

Would brake vectoring still function?

 

[RAAMaudio]

Torson types tend to unlock when lifting a wheel which may happen during a rallycross, it would the way I drive at least
But, the Torque Vectoring mitigates much of that effect and I like the smoother engagement of that type of diff.

Clutch diffs need to be specifically dialed in for the use to be at their best or can cause more harm than good in extreme cases.

The more plates generally the smoother the diff can be tuned.

All that said I am not sure if it matters as much as slipping around on dirt so much if a clutch diff needs to be one of the high cost many disk units, never ran a clutch diff in the dirt in all these years.

Perhaps somebody here can make a more educated, experienced, etc recommendation.

 

[WAM]

Didn't you go with a Wavetrac? How did that work out?

Or maybe I'm thinking of another post.

 

[RAAMaudio]

I went with the Quaiffe as it was the only option in mid 2014 and am happy with it.

 

[M-Sport fan]

Didn't you go with a Wavetrac? How did that work out?

Or maybe I'm thinking of another post.

Pete is the one who went with the Wavetrac.

http://www.fiestastforum.com/forum/threads/4054-The-Evolution-of-the-Green-Beast

http://www.fiestastforum.com/forum/threads/12820-LSD-and-Final-Drive-Installation

 

[RAAMaudio]

I might of tried it or would really liked to have installed an OS Giken, had one for a pretty wild E36 M3 project, expensive at around $1800 but not made for this car at least at that time.

 

[WAM]

The Achilles heal of Torsen LSDs is no locking if one wheel is totally without traction -- in the air for example. Rallycross is all dirt and bouncing about, so that condition may be frequent. But we have TV to apply drag to a spinning tire. Has anyone with a gear LSD noticed a spin-up issue under any conditions on a FiST? I'm thinking that a Quaife may be all that's needed on this car.

 

[Jesse]

I've been to and done a ton of rally-x. Who lifts a front tire on the regular? I've certainly never seen it happen, doesn't mean its not possible but there's just really not enough grip to lift a front wheel that high especially with stock or rally type suspension that has decent travel in the shocks. You'll be just fine with any LSD style IMO. Plus torsen are generally a lot nicer to drive than clutch type on the street unless your a full race car and don't drive on the street. I've had both types and I prefer torsen for street cars that do a little weekend warrior rallyx/autox/road course (which is pretty much everything I've done) except drift, I was most happy with a clutch pack 2 way in my old drift car (R33 Skyline)

 

[M-Sport fan]

The Achilles heal of Torsen LSDs is no locking if one wheel is totally without traction -- in the air for example. Rallycross is all dirt and bouncing about, so that condition may be frequent. But we have TV to apply drag to a spinning tire. Has anyone with a gear LSD noticed a spin-up issue under any conditions on a FiST? I'm thinking that a Quaife may be all that's needed on this car.

^^^Supposedly, the Wavetrac addresses this shortcoming, actually one of the bullet points in their marketing of this diff.

 

[RAAMaudio]

I have jumped many curbs on track, driving in all sorts of weather except just a tiny bit of light snow and never felt like I had an open diff, not once with the Quaife, I think the TV takes care of that issue quite well at a bit of cost of using the brakes up a bit more, good to have coolers for the track.

 

[WAM]

Yes, I'm aware of the Wavetrac design intent. I have one in a supercharged Rabbit rallycar. Seems to work as claimed.

But since the FiST has TV, and RAAM confirms the Quaife seems to stay locked, I think that will do just fine. Less complicated is a good thing for those of us who have to pay others to R&R the tranny.

 

[RAAMaudio]

Best regular style clutch LSD/diff I had cost nearly $4k, hand cut ramps, Porsche disks, ring and pinion and other parts micro polished. Clutch diffs with a lot of disks like the OSG which has 20 I believe can hold up longer and have smoother engagement in accel and decel and be much easier to drive making for faster lap times.