Kaaz, Cusco, Spoon, ATS, Mugen, etc
What makes one better than another? Looking into 1.5way for track only use.
Looked through search already but other than carbon ones being little quieter I didn't really learn much.

 

you can change it?

 

Yes (for T2 diffs are open to make sure that all cars have one). UL was telling me it's a noticable difference (on track) to switch to a clutch type.
Found in the archives that Spoon is a rebadge Kaaz. (weird)

 

Anybody even have any lap time data going from stock diff to a clutch type (without other mods at the same time?

 

none that I know of. The JIC vs Stock comparo had a Kaaz 1.5way involved as you know.

I keep thinking I should be using one. If I were to get one, I'd get a kaaz. Avoid the JDM crap. (excluding mugen of course). But mugen I believe only offers a 2way which they claim they found to be the best for the s2k, but I'm not so sure about that.

 

Rylan,

I would look into Cusco RS LSD as well. They are used in the actual JGTC cars.

 

You can't compare with JGTC cars. If you were at Fontana last month, you would know that JGTC cars are basically carbon-frame GT Prototype cars - not production based at all (except that they throw the stock firewall in). Data from JGTC has zero relevance to our cars.

I often wonder how much my kaaz helps or hurts my car's performance. It definitely improves the FEEL of the car though. Also, it's nice to have control over the amount of diff lockup (by use of fluid changes, you can modify the amound of friction modifier and therefore the amount of lockup). I actually didn't realize how much you could change the characteristics of the diff by just changing the fluid mix, but now that I know, it's a nice variable to play with. I find that I like a lot of lockup on the street to kick the tail around corners and have fun. On the track, I like it a little looser so the car doesn't respond so violently to throttle input (so I add more friction modifier).

 

I have been tracking for 5 years now. "AMERICAN IRON" Mustang, Camaro, M3, 94 Corvette. and now my S. I find that the factory diff is AWSOME!!!!!!!!!!!!!!!
Stick with it!

 

The stock diff just doesn't offer enough forward bite coming out of corners. With a more aggressive rear diff (of whatever type, but that means clutch type with the S2000 right now) the car gets better traction and is also more pointable on the throttle - and asks more of the driver in the process. I was amazed the first time I drove Karner's car at how much more the throttle controls the attitude of the car with the Kazz. When dealing with noticeably more powerful FWD cars (damn Honda Challenge rules), the first 100 ft of acceleration off the corner is sometimes the only thing that kept David ahead through the next straight.

That said, it probably does require a little more care than the stock diff when driven hard. An open diff RWD car is very hard to rotate on the gas. The stock Torsen type in the S2000 is easier to generate power oversteer with. With a 60-70% locking clutch type Kazz, its very, very easy.

UL

 

Shawn, my concern is that I've noticed too much lockup can DEFINITELY slow the car down. On corner exit, you run into issues where you can create power oversteer very easily because the diff is too locked to allow the rear wheels to turn at different speeds and you get a go-kart effect. You can balance that out by tuning the suspension for some corner exit understeer (more front rebound, less rear compression damping), but I think your resulting exit speed can often end up lower, even though it feels crazy fast. I'm still trying to figure out just how much lockup works best, but I would suggest you play with running more friction modifier and checking the effect on times.

From what I've seen so far, it seems like it works best to keep the diff lockup as low as possible where you don't get inside wheelspin - but I'm definitely still learning what works best.

I know Karner's driving-style probably works best with lots of lockup, so you might have a situation where what's ultimately fastest for the car isn't what's fastest with your particular driver - in which case you might see the fastest times with "too much lockup" simply because Karner will drive best like that. I dunno. Like I said though - it's definitely worth playing around with.