So I was looking for some stuff about LSD's and stumbled across this page:

http://www.club4ag.com/faq%20and%20t...ential_101.htm


I quote,

Contrary to what manufactures want you to believe, TRD-Toyota Technocraft, Mugen-Honda Racing, RalliArt-Mitsubishi Rally Operations, MazdaSpeed-Mazda, STI-Subaru Technica Int., NISMO- Nissan Motorsports, all have their LSD's made by the same supplier, a Hitachi subsidiary. This is because the majority of the normal differential gears are supplied by them. They use the cheap factory casing and re-work the inside. This limits the size and number of the gears, and clutches thereby sacrificing true potential. They claim 4 pinions but have only 3 or 4 small clutches on one side. They use very high cam profile to put high loads on the clutches so that it can achieve high lock up. The problem with this approach is that the pre-load on the clutches are higher and tires have constant drag. Also, since the clutches are small and few, the load is larger per given surface area, translating into higher operating temperatures and fast wear. Another major disadvantage to this type of LSD has to be the abrupt lock-up, making on-off conditions less predictable and controllable.

The true high-quality Limited Slip are supplied by Kaaz and Cusco, who supply majority of racing teams throughout Japan. The Cusco and Kaaz differentials have on the average 10mm oversize clutch diameter and computer stamped oil channels which hold lubricants during operation. The plates number from 6-8 and have very wide selection of pre-load springs to choose from. Since the clutch has to press together less to achieve very high lock-up, the LSD generates less heat and wears much longer. All components are computer ground and shell casing is not stamped as in the OEM and Branded Hitachi units. Over the long run, these units will cost less to operate due to the lower maintenance required in terms of rebuilding and replacement of clutches. Most of all, these LSDs are much more controllable, having a wider, more progressive lock-up and better positive lock up at the limit. They are more streetable because it won't suddenly spin you around in low traction conditions such as rain and snow. You can, but you can also be in control...

To add to this, Kaaz differentials have higher quality tolerance levels, represented by computer balanced shell casing and gears, and initial pre-load springs are matched to vehicle applications. The reason for small application list is that they go through 3 years of N1 and Gr. A racing to design the differential design and specifications. I prefer the KAAZ because of cheaper entry price tag too, made even better by introductory pricing in the US markets. Consider it the ultimate in LSD.



Does this mean we won't want the OEM LSD that comes with the RS when it hits our shores? And why aren't Cusco, Kaaz, Quaife, or any other aftermarket suppliers making LSD's for us? Damn USDM spec.

 

the stock diff are top notch units. Putting a Kazz LSD will prove not true benifits in the rear. Now launching an AWD car will beat up on ANY diff, stock or not. Many roadracers have been using stock diffs for decades, only some cars have ****ty/weak diffs, not ours.

 

only thing it means is that the stock unit isn't designed for race application meaning if your intent is to strickly autocross this car your coing to wear out the stock units after some time. Its common sense, if i'm going to use this car for compition like D1 or autocrossing, i'm more then likely not going to choose a stock LSD over an aftermarket one... For the novelist racer the stock unit will be fine...

 

Ah, I meant in reference to the front LSD, not the rear. As we saw, a couple people (including Buschur) blew their front LSD's already, pretty easily too.

 

What are you taking about? Not on an evo. Right now there is no front LSD available for the USDM Evolution. Until the RS comes out we'll never know.

 

That's what I'm saying - the article makes a reference to OEM LSD's being lower quality.

Thus, I am wondering if maybe the front LSD we are getting on the RS (which can also be retrofitted into our current Evos) may be weak?

 

From the many things I've read during research on front LSDs, Quaife will NOT be making one, while Cusco is supposedly R&Ding one for the US market. It will not be cheap, count on that. However, I'm not convinced that an LSD up front will be that great. During their reviews of the US-spec Evo, two UK car magazines, CAR and evo both felt that the US-spec car was actually MORE fun without the S-AYC/ACD and an open front diff. I think I would get the Mine's CF driveshaft before I'd get a front LSD.

 

I've spoken with some of the Evo6 TME owners whose cars have almost the same differentials as we do - open in the front, and mechanical rear. Most of them recommend getting a LSD as the FIRST and most effective mod to cure understeer.

Claudius recommends it too, then followed by suspension (IIRC). He believes that the strut bars do very little for the money, and that they would be better off spent elsewhere. But then again, he does run the Ohlins GroupN coilovers, which are easily $6000 a set....

 

EDIT: In the above post I meant that a lot of the Evo6 TME owners also junked the AYC for a RS type mechanical diff (like ours).

As far as I know,

ACD is (though not terribly useful unless you do on the limit driving to utilize the other settings)

while

AYC is While it keeps the rear glued to the ground, it causes the car to push like no other.

 

i think this doesn't apply to mitsubishi lsd's. they create their own lsd's in-house. they create them with license from an american manufacturer. its a superior design cone type clutch that increases surface area and reduces temps, maybe, i could be lying.