949Racing is now offering the fantastic OS Giken limited slip differentials for all of the usual suspects:

• Miata
• S2000
• EK9 Civic
• MX5 NC
• C5 & C6 Vette
• Evo8
• Elise
• Mini R50/53 & R56 (gosh do Mini's need this diff!)

Hey its moving, what th..

 

You have one in your own car yet?

 

Only one left at OS Giken so I have to wait. I did get to fondle it and take pictures before sending it to a customer though, does that count?

The OGK is the the fabber's place getting the cage put in. I'm sorting through the VVT harness right now to get the thing working with my ECU. I figured I could wait and the customer wanted it now. Can't wait to get it in and dialed though. I'll have a 140 in/lb RX7 diff, type II torsen and OS Giken to compare. I can't imagine being ambitious enough to do swaps at the track though.

 

I've been wanting to do this test. Don't have an OS Giken or Cusco diff to compare with.

 

hopefully the OS Giken is a little smoother than the others during lift. that's my complaint about the Kaaz--it's so abrupt. you can't lift to bring the rear end around at all, unless you want to bring it in front of the front end. it's that harsh.

 

That's where the LTCS (Lock Timing Control System) comes in. In a typical clutch type, enough preload to get the locking ratio you want also increases breakaway torque. I've driven those too, meh. The default settings on the OS Giken are pretty benign, being as close to a full race set up as possible without being unpleasant on the street. Tip into the throttle a tiny bit mid turn and not much happens, dip into it hard and it progressively tightens.

The way the LTCS cams work they are actuated either by torque or extreme differences in axle velocity. They're tuneable by changing ramp shapes, reversing them and changing the preload on them which is separate from the main plate preload.

Short and sweet, the OS Giken feels like the Torsen in my S2000; You can feel the torque channeling to the inside wheel at low speeds but it's completely controllable and linear when you jump on it.

I've driven the Kaaz in a Miata. My comment when I jumped out was "wow, the diff make this a great drift car". Impossible to do anything but corner with the tail out but if that's what you were trying to do, it was fabulous.

 

This diff sounds incredible,I'm seriously considering this over the ATS & guru diffs.

 

The ATS (Carbonetic) is traditional clutch type, very well engineered and manufactured. The Guru likewise, is a traditional helical "Torsen", also very well engineered and manufactured. Both work very well but have limitations the OS Giken doesn't have.

I looked at the ATS myself and think they're probably the best option in a traditional clutch type. But the OS Giken is about the same price, easier to drive, not temp sensitive like the ATS carbon and far more tuneable.

 

After a long period of no diffs, we now have a bunch in stock. Every OS Giken Miata diff we ship incoprorates our multi national championship winning proprietary SuperMiata tune. This tune involves, among other things, swapping internal components that would otherwise add about $700 to the cost. As we get out diffs made for us to order directly from OS Giken Japan, we are able to pass the trickness along at no extra charge.

 

I've been eyeing an OSG diff for a long time to test in the K24 Miata. Once I do that, I'll send people your way.

Emilio, you installing one in your K project?

 

FAQ from OS Giken about approve alternate lubes. We have found that the OS Giken is particular about the lube used. We only use the OS Giken OS250R stuff in our diffs here but they are always diffs, not transaxles. There are OSG approved alternatives for specific uses.

• Motul Gear Competition FF 75W140 - (FWD Transaxle, AWD, and RWD Applications)

• Motul 300 75W90 N/S - (FWD Transaxle, RWD)

• Swepco 210 – (Old Porsche 915/930 Gearbox Applications)

• Motocraft Synthetic Gear Oil 75W140 - (FWD, Transaxle Applications)

 

Sweet. I'll be testing that Motul 75w140 once I get my diff back together.

 

Sweet. I just bought some OS250r from you...

Do you plan to stock some of the Motul?

 

I posted that on a local forum and one guy said he already tried the Motul in an OSG-equipped miata. He said the lockup was pretty harsh and he switched back to OS250R.

 

The motul blend specified?

 

Yep. His quote:

 

I have not tested any other lubes in the OSG's. Just sharing their recommendations.

 

Soo, old thread revival, I was looking in the OS Giken catalog today and noticed that they no longer list an LSD for the NA/NB Miata. Can anyone confirm/ deny whether they do still in fact produce them? I know a variety of websites still list them, but that does not mean OSG still produces them.

//Thank you

 

Still available. The "SPM tune" version we offer is custom tuned by us, built in Japan by OS Giken. No extra charge for the custom tune.

 

Do you guys do LSD installs? Say if I mailed you a carrier, some 3.3 gears, and then bought a OSG could you put it all together for me?