rominl

iTrader: (4)

hahhaa, the story is over

Cannonbear

will the 3.92 diff work? It'd work better with LSD. I'm also sure of the accel being greater along with the TC, though it may just make a lot of smoke I know of one sc430 owner putting the 3.92 on his.

The only downside i see is gas mileage and traction, maybe some TT supra wheels for the rears would help.

RMMGS4

iTrader: (5)

You are dead on with that statement.

Those of us with the 3.76 can already smoke the tires, even those with 20's can break loose at will.

Even with a 285 size tire I still can't launch hard enough to use the cars available torque. A 3.92 is only going to make this worse. You need to put the stickest tires you can find on the widest rim to tame the 3.76. Atleast a 295 or 305 size tire. I am leaving drag radials out of this conversation however since most of us , wouldn't use that as a daily driver tire and I assume the point of this discussion is real world street performance.

There have been several discussions on the topic of traction, launching , best 0 - 60 using the 3.76, with TC, etc.

The limiting factor IS traction. The 3.92 might be better for acceleration IF you can get the traction or only care about rolling starts and high speed acceleration.

I'd say for best performance from a standstill, that the 3.92 is too much gear already, unless you wanna tub your wheelwells and put on 335 size drag radials, etc.

rominl

iTrader: (4)

yup i agree with rmmgs4. yes the 3.92 will rev up even faster and harder, and as long as you dont' care about any speed after 120mph, everything should be fine. the only problem is traction. teh massive 300hp and more importantly the 310tq on the gs4 is what putting so much force on the ground. if you get 3.92, you wanna make sure you fit some 11" wheels in the back with possible 295 or even 305 tires

supergs400

3.92 rear end works on the car, the only downside is the top speed is about 130mph. Not having any traction problems, have tom's stuff on the rear, but it does accelerate alot quicker.

RMMGS4

iTrader: (5)

We don't have traction problems either. I'm saying that the limiting factor on the 3.76 and 3.92 will be traction, when launching from a standstill. We did the testing using several local cars with different combinations of 3.76 gears, stock gears, LSD, w/TC, 285 size rear tires and mild engine mods. We tried different launching tecniques, drawing the conclusion that traction was a key factor. Another perspective is the more power you have over stock, the less gear you should run. For those who have gone FI a 3.76 gear is not even recommend, a 3.92 would be even worse in that case.

The bottom line is we measured our 0 - 60 times using a G-Tech. Best times achieved were between 5.2 & 5.4 sec. It would be great to get 0 - 60 times tested on a 3.92 geared car.

We know your car will accelerate a lot quicker, but it would be better to have tested numbers to evaluate any real gains compared to a 3.76 set up.

If you can get some 0-60 times measured and list your mods, then we're getting somewhere.

rominl

iTrader: (4)

you mena you have 3.92 rear end on your gs400?

daleer

I've been looking for a supra tt 3.76 for my gs430 but damn they're expensive - over $1500. Where could one find one of these cheaper and more available 3.92 lsds??

rominl

iTrader: (4)

well the 3.76 is very rare, and for new, that's about the price you looking at. you can always try your luck on supra forums here here on CL to see if someone is selling it. that would be a lot cheaper.

and for 3.92, as far as i know they don't have lsd? correct me if i am wrong though

chuckb

are there any gears between 3.23 and 3.76 available? like a 3.55 or something?

rominl

iTrader: (4)

umm interesting question, not that i know of...

the is300 5 speed has the 3.72 rear end lsd

Swainbuilt

iTrader: (3)

From the reserch I have done it seams that a LSD was available in the 93-95 SC400 with 3.92 gears!

supergs400

Yes the 3.92 rear end is on my car, got it cheap and wanted to try it out. Changing the gear ratio was the best thing that I did for cheap performance, helps out with city gas mileage too. Car also became more responsive. Freeway driving suffers a bit though, 22 mpg frwy is the best that I can get with a top speed around 130mph. Have not tested the 0-60 times yet, will have to try it out on the Gtech sometime later. The car does have pretty much all the Tom's stuff, except the rear STB (need space in the trunk), HKS Hiper II Coilovers, OEM 17" rims with 255-40-17 tires all around, first generation Rod Millen steel intake with an upgraded K&N filter 8" long (car was an earlier Rod Millen signature series partially taken apart). I am working on my other car now (Integra turbo with full suspension ) and don't have the time to play with the GS that often.

supergs400

The LS400 has a 3.55 rear end, but I don't remember which years to look for. This is a compromise that I was thinking of doing, but don't have the time.

rominl

iTrader: (4)

wow man, 3.92 on gs400 with only 255 tires on the stock 17s, surprise that you don't have traction problem off the line