Skier1,
I drive a '01 GS430. I'm just planning to do the LSD upgrade. Had I wanted to fully tinker with the car I would have purchased a GS300 instead since the performance parts for the 2JZ-GE engine is infinitely much more than the 1UZ-FE / 3UZ-FE series. To make the V8s perform like their souped-up inline-6 counterparts, you simply have to spend more.

By the way, you mentioned that the RMM LSD is merely a Supra TT LSD? Would you happen to have the part number for this? Thanks, bro!

 

One more thing, after the Supra LSD swap, does the car need to upshift to 3rd gear in order to reach 60mph or can it do it with 2nd gear without hitting the rev limiter? The GS430 does a maximum of 41mph on 1st, 63mph on 2nd, 97mph on 3rd. I suppose these values are similiar to the GS400 as well.

 

is2000,
please forget about the hit the limiter comment, i think you don't understand this, you can't hit the limiter in high gear, other than in 1st and possible in 5th at 132mph, and you don't hit it unless you SMASH THE GAS PEDAL down to the floor and hold it there (only a few see this problem, NOT ALL) You probably never see this since yours is a 430, the ULEV for emission w/o eshift will probably never let you to stay too close to the redline.

basically, with your normal driving, you don't any different but the RPM is a bit higher, ie cruising speed rpm

Do a search on "supra LSD", you will find the part number for it or just all toyota dealership.

 

I was too worried myself about hitting the rev limiter so I just got my ATS carbon fiber LSD myself. I prefer clutch type MUCH more than the Torsen type which won't help me at all in certain sutations which I am apt to see here in Michigan. I was thinking about getting the Supra unit and swapping out the LSD for a clutch type but it would have required me to change the axles so I stuck with the stock FD gear and ATS LSD which just arrived today. The carbon was a few dollars more than the TRD unit but can handle a lot more power, smoother in transition from lock to unlock and will probably outlast the life of the car. I'm geeked. Can't wait to install it.

 

The RMM differential is of the Torsen style & not the clutch variety so 400 HP is about it's limit.

 

Via Guru, my ATS Carbon LSD is also on the way. I'll keep everyone posted as to progress. I decided on the ATS for several reasons, but one of the primary was that I hope to add significant power in the future and the combination of a high stall TC and a higher than stock final gearing [3.76] is not recommended for FI.

 

The ATS can handle 1200 HP.

 

Guru, ha ha ha
at 12000HP, what good is it if your engine fall apart, all the diff gears are broken, but the LSD itself ho ho ho

 

The ATS carbon LSD is made for a variety of vehicles, many of which are often built to a HP level far higher than our GS' will every see, including the SRT TT monsters. It's nice to have a "small" margin, for safety sake.