O.S. Giken "DualCore" LSD

prandelia

Seems like play toward the more street oriented, or dual-purpose crowd, that don't want to use a diff cooler, which is basically everybody with these cars.

I actually am pulling my 1.5 OSG LSD to send back to them for a rebuild and setup change. Ever since going to stiffer springs and sticky tires like RE71RS, the inside wheel spins so badly in corners and curbs, it's not even worth driving anymore at the track. Not sure if it's all my car setup/power, or a combination of high wear when I first installed it and didn't have a diff cooler for a couple track days, and only had a Z1 diff cover (which are absolute garbage BTW, they actually increase oil temps because they don't adequately lubricate things inside like an OEM one does with the rounded interior). Trust me, everybody should ditch those and just use the Nismo cover, which I did switch to, in addition to a cooler.

Regardless, the LSD needs adjustment.

The idea of a Wavetrac sounds great, but the lack of lock on coast/decel still bothers me. Who knows, maybe they still work great on track. Not having to run a diff cooler certainly would be nice, and make diff oil changes a helluva lot easier.

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2014-Nismo 370Z / 2025-992 GT3RS / 2024-C8 Z07 / 2018-991.2 GT3 / 2011-997.2 GT3RS / 2016-981 GT4 / 2013-E92 M3 / 1988-E30 M3 / 2015-FRS - GLTC race car

redondoaveb

1) The OS Giken is tuned from the factory for stock power and street use. It definitely needs to be tuned for track use, and/or higher than stock power

2) I completely agree with you on the Z1 cover. I scrapped mine for my new build and had a Nismo cover installed instead.

3) Rob Fuller from Z Car Garage runs OS Giken's on all of his race cars, including his IMSA car and doesn't run an oil cooler on any of his cars and has never had a diff failure. Take that for what it's worth but he's a reputable source.

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Fast Intentions "Stage Seb" twin turbo #098- Specialty Z/Tial-Xonarotor/CJM/Ecutek/HKS/KW/SPL/Hotchkis/Rohana/Toyo
750whp/700ft.lbs

Spooler

I puked diff fluid out the vent tube of my OS Giken on the Tail of the Dragon. In my eyes, you need it. Plus, your diff fluid last longer. No need to change it after every track day.

prandelia

Agreed. My car would have puked regardless of what diff cover I had on my car with the OSG LSD on track.

I think between my aggressive track setup (springs/bars/tires) etc. and making 340 WHP, along with the 3.92 final drive from the 2016+ Nismo, it just puts too much power down for the OTS setup.
I should have consulted with them first, because most of the time their OTS setups work great for track cars, but just doesn't seem to be the case for the 370.

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2014-Nismo 370Z / 2025-992 GT3RS / 2024-C8 Z07 / 2018-991.2 GT3 / 2011-997.2 GT3RS / 2016-981 GT4 / 2013-E92 M3 / 1988-E30 M3 / 2015-FRS - GLTC race car

Spooler

My car was bone stock with the 3.69 OS Giken. No tune. All I had was a 2.5in. Fast Intentions exhaust. Suspension was upgraded, wheels and tires. This was before I went twin turbo.

cv129

Many years ago, I caught a video from Gale Banks (Banks Power) on diff cover interior curvature and how that affects fluid temp, aeration, gear lubrications, etc etc…he had an experiment with clear diff covers to show the theory. Since then, it was an easy conclusion for me to skip the Z1 cover.

When I do diff upgrade, Nismo cover will be my choice.

He even did air flow testing behind the diff cover and came up with a pretty cool design to guide the moving air into the cooling fins. Wish we can have that.

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Setrab | RE-71 | SPL | JRZ | Nismo | ARK | Whiteline | RacingBrake | CJM Oil Pan | Ti shield