stantaur

Apologies for the mis-spelling of Belleville. I can't edit the poll unless the mods go in and revise.

That said, I want to collect people's insights on the various diffs people have used. I haven't found a consolidated thread/location where all of this information could be easily found. There's a good bit of Cusco experience with the 350Z guys, along with notes from various other places, discussions with vendors, etc. Some loosely organized notes I've accumulated are below.

Please share your vote and post what your experience has been in terms of:

- Engagement grip on corners / ability to not spin the inside tire (satisfaction 1-10 scale, general notes)
- Understeer or push encountered
- Degree of "snapping / popping" at low-speed high angle maneuvers (cold vs. warmed up)
- Fluid change intervals (after every 3 autocrosses, after 3000 miles, etc.)
- Fluid brand and weight used
- Price of LSD unit
- Rebuilds you've done so far on this installation
- How long you've had this LSD in your car
- Number of autocrosses per year you run and milage per year you run

NOTES (your mileage may vary)
Cusco RS ~ $1000-ish
RS uses a gentler engaging "coil spring" mechanism than conventional (loud, harsh engaging) Bellevue washer design of the Cusco MZ (and Kaaz = Cusco MZ design)
Diff is adjustable from 1.5 way (unlocked on decel, locked on accel for auto-x, track, street) to 2-way (drift, wherein it's locked on accel and decel)
Diff can be "toned down" from 100% clutch engagement on lockup down to 80% or 60% of clutches engaging
Toning down to 80 or 60 percent may reduce service life (less surface area = more slip), in exchange for less severe popping under 10 MPH in parking lots and less push / understeer
Lots of installed base and design has been out in the market since early 2001 per conversation with Cusco rep 12/08
http://my350z.com/forum/engine-drivetrain/...ots-pics-2.html

http://my350z.com/forum/autocross-road/337...tml#post6687953
http://my350z.com/forum/engine-drivetrain/...sd-reviews.html

Clutch replacement pack costs $251 retail list, part number is lsd 00122
Based on everything people write about ANY clutch diff, if you change the fluid every 3 autocrosses (or 3K miles) you'll have a quiet, long-lasting diff

OS Giken ~ $ 1300
Strong press around them using smaller, hardened spider gears to make room for more clutch plates
More clutch plates are supposed to provide gentler engagement, less slip required to activate and longer life.
Design incorporates coil springs similar to Cusco RS, but working in an opposite direction in order to provide more progressive preloading and transitions.
Very elegant design and everyone who's seen one says it's a very high quality made piece. May balance out more accurately than other brands aside from OEM Torsen.
Not as many people using them in S2000s and 350Zs, but it looks like OS Giken makes the units for a wide array of vehicles.
Clutch replacement pack costs $650 list, but OSG reps say that they have yet to sell one - even first run LSDs have yet to be rebuilt after years of use.

ATS Carbonetics Carbon- $1500 plus more expensive oil
Many good reviews; people that have 'em love them in most cases. Least amount of chatter/pop for any clutch LSD. Several caveats though.
http://www.fitfreak.net/forums/fit-trix-ge...mpressions.html

Caveats include frequent oil changes (carbon residue wears bearings and ring/pinion), and the oil is $50/gal plus shipping
Dig deeper, and you find issues with the adhesive used to bond the carbon material to the discs, and carbon material ruining bearings.
http://my350z.com/forum/forced-induction/3...tml#post5502034

Cusco MZ and Kaaz
Effective, but harsh engagement and popping may deter street usage.

Torsen / Quaife
Great for street, very quiet. For auto-x, if you pull a wheel up on tight corners you have an open diff situation
When wheel lifted in tight turn, bouncing that spinning wheel back down can frag the stock Torsen LSD
Quaife is a beefier version; unlimited warranty (incl racing)
Unsure if Quaife breaks when you bounce the inside tire though

TheNick

Belleville washer, not bellevue.

Aside from that I have nothing to add other than everyone I know that has used an ATS Carbon diff has absolutely fallen in love.

feintmotion86

I actually signed up for an account here just in case an F20 came up for cheap (I'm an AE86 guy) but I think I've actually got some knowledge in this case to help you!

AE86 people also have a large variety of differentials to choose from and often times aren't sure what to use and don't fully understand the features of each. I've talked to tons of people (pros and grassroots people alike), driven on many of the LSD's myself, and here's the general consensus I've come up with.

Cusco RS:
Probably the all around best LSD for the money. Its in the middle in terms of up front costs, but yields fantastic performance from its easier engaging mechanism. Its operation is relatively quiet, and since Nukabe is a solid Cusco dealer, finding repair/overhaul parts shouldn't be a pain.

OS Giken:
Taka Aono and Hiro Sumida, both Formula D pro use this LSD on their cars. they really can't say enough good things about it. Its at the higher end of the price point, but I don't think there are any other LSD's on the market with more clutch plats available. As you pointed out, more clutch plates = less wear per plate, meaning longer service life. The lockup is pretty rediculous and the service interval will be long, very long. Because of this, maybe the higher initial invetstment is moot.

KAAZ:
I think perhaps this is the most popular of the clutch type LSD's for several reasons. First, they are at the lower end or the price scale, while still delivering very, very good performance. The number of clutch plates is still pretty high, and the service intervals still seem to be pretty long too. You still get the nice forged casing, large number of clutch plates and heavy duty internals for slightly less than what other manufacturers charge. Second, is the fact that KAAZ has an actual US branch (for which many of us southern californians is local) and will do many of the service/repair themselves. They built the diffs, so they know how to properly service them. Repair parts don't need a two month turn around as they are usually in stock, and their customer service is fantastic. If you need to modify your diff for a different lockup rate and/or adjust something internally, they will usually do it for you ahead of time free of charge (when you buy a new diff).

After mentioning all that, I'd say that any of the above brands will be fantastic. There's other clutch types I haven't tried (like the ATS, cusco MZ) but when it comes to LSD's, there aren't really any "crap" companies that make them. Most of them have forged casings, heavy duty internals, large number of clutch plates, and motor sport heritage to boot. This is why I brought up the customer service and availability aspect of KAAZ, since it kind of seems like the majority if LSD's are pretty good. Sometimes the performance is so close, that you have to look at other points in order to make your decision. Good luck with whatever you choose!

blackey

FYI,

Kaaz has a new diff out call the super q. It is touted as having even higher strength, no break in, and is OEM quiet.

I have not seen one yet, but Kaaz is pretty well respected.

Bill

INTJ

For your street / autocross criteria, I would look closely at the Torsen T-2. This version has much better ramp up characteristics and doesn't have the same rear lift issue as ours.

Billj747

AutoX has different introcacies and demands than road course use...

mikegarrison

Specifically, I think you mean the T-2R. It's the R version that is preloaded to avoid the lifted wheel issues. The S2000 already has a type T-2. http://www.torsen.com/files/Torsen%2...on%20Chart.pdf

But is there a T-2R that drops into the S2000? From Torsen: "The current applications for the TORSEN T-2R include the Ford 8.8 inch axle, the GM 8.5 inch axle, and the GM 7.6 inch axle."

Billj747

T-2R has a little better holding capacity than the T-2. Engaged sooner and allowed less inside wheel spin. IMO it still allowed too much inside wheel spin and didn't engage quite early enough. -road racing a Ford Mustang FR500S and FR500C 320-450hp cars.

Again, I would get feedback from autocross-specific people as the setup in autocross differs from road racing (in terms of demand, what works better, etc...)

TubeDriver

All of the units you list except for the stock OEM diff will throw you in BSP where you will get killed (assuming there are any relatively competitive BSP car in your region). If you want to trophy and you are a good driver your best bet is to keep the OEM diff and run AS. If you just want to have fun then do a bunch of mods and go BSP.

TheNick

Dude I don't know if you noticed, but he's already in SM2.

'02 S2000T - Track Toy, Laskey 2.0L GT3076R motor, PuddyMod Racing diff, Moton CS, CCW Corsair C10s. 421 RWHP/285 RWTQ