TLW

ok

im hoping this is possible

instead of taking the whole supra rear is it possible to just take the LSd unit and put it into our s

im not fond of how tall the gearing will be

figured to just take the LSD from the supra and swap into ours

has anyone done this

or is it even feasable

rominl

iTrader: (4)

to be honest i dn't recall seeing it done yet. my guess is it's doable, just a lot of work as usual. but again i don't think anyone has done it before.

my question would be though, if you are doing that, why not just use the trd unit?

TLW

this is why

The TRD LSD is a standard type LSD in that it uses clutch packs to transfer torque from one wheel to the other. Transferring torque via clutch packs is a slower process than the Torsen transfer method and it will absorb more energy from the engine when doing so. However we are probably only talking a few hundreds of a second difference here and maybe a few hp. The main disadvantage of the TRD diff is that it can "lockup" the ratio between the two wheels at 1:1. This means both wheels will then turn at the same speed and if this happens on a corner, it would be exciting at the very least. This "lockup" is also its only advantage over the Torsen diff as even when one wheel is in the mud, the other wheel can provide traction to pull you out.

and

Require special gear oil with added friction modifier to prevent accidental lockup. Recommended 85W140. Clutch packs will wear out depend on your usage and will need rebuilt

rominl

iTrader: (4)

umm, interesting. i think redgs4 is the person you should talk to. he had the clutch type and now the torsen, he can tell you more. he told me something about 1 way, 1.5 way, and 2 way locking lsd.

he explained to me and i understood, but kinda forgot already. i remember he mentioned the "bad" about the torsen too, which i experienced when doing hard turns as well. so you gain some you lose some.

and for wear, the gears on the torsen can wear too. but everyone knows that the supra unit is strong as hell

joshoowa

iTrader: (1)

pointed JPI to this thread hopefully he can answer this.

TLW

this is the LSD unit

i wonder if this can just be put in

if it can then these are worth $100 shipped from supraforums

TLW

ok talked to one guy he said i could do it but that the speedo would be off

any clue to why ??

FutureGS400

I would disagree about the speedo being "off" as a result of gearing changes (or in this case, a Torsen LSD carrier install). Changing the O.D. of your tires will affect it, but not gearing changes.
Also, the TRD shouldn't "lock" the rear wheels going through a turn as you described. Unless something is malfunctioning perhaps...
I have driven a number of vehicles with true locking diffs (Detroit Locker and ARB Air Locker) and in the case of the Detroit Locker, yes it can be a handful on the street if you're not careful! The Air Locker is only engaged when full lock is desired for off road use etc.
It's true that the Torsen will not send power to the wheel with traction if you have NO traction to the other wheel at all. To overcome this, apply the brakes enough to provide resistance to the spinning wheel. Humvee owners use this trick all the time off road (REAL Hummers, not the H2).
I would recommend just swapping the whole Supra rear end with the lower (shorter) gearing. You will see a noticeable performance improvement in addition to better traction. If top speed isn't an issue for you, the increased RPM while cruising isn't really bad at all with our smoooooth V-8s!

EDIT: I just realized you are doing a S/C install. In that case, the 3.76 gearing is not optimal according to most S/C guys (as you probably already know). Not sure if the Torsen LSD would work OK with the stock ring and pinion...

rominl

iTrader: (4)

i agree, i don't see why the speedo will be off?!

HI98GS

from what I researched, it seems that the part numbers for the LSD for the JZA80 and JZS161 are the same. The only catch is that these JZS161 has the same motor as the supra. So they may be using the same rear diff. You should probably ask Steve Ganz to see if the part numbers are the same for the GS4 and the Supra TT.

Good luck

TLW

thanks guys ive decided to go with the supra rear and possible have the TC taken out and make it 2400 stall like davegs4

i know some feel this isnt the best setup but for what i want ...it is

thanks again for all the replies

now to find a supra rear

RMMGS4

iTrader: (5)

The 3.76 will work with a SC car, but you might have to baby the throttle to keep from melting the tires down every time you launch it hard. If you are racing, either street or track, it will be harder to launch the car quickly without spinning the tires too much. We already have this problem with the 3.76 on a NA car, so what more with FI? If you are exiting a turn and jump on it too early, you could easily bring the back end around and spin ( with VSC off). Didn't another SC owner do just that?

So I think drivability with regards to quick launches and lower ET's is what FI people are talking about. If you don't mind kicking the rear end out at will, for fun, and love spinning the tires instead of getting lower ET's, then it might be OK with you. Also the gear ratio may actually not prove to be faster in 0-60 or 1/4 mile than using the stock gearing.

I'm thinking if you drive with VSC on, it might trigger all the time if you do a lot of spirited driving. i.e. LEADFOOT !

Now if you can put some super sticky Michelin PS2's on a 295 size tire with an 11 inch wide rim, out back, then this might not be as much of an issue.

Whatever you do, be careful, respect your new found power and enjoy.

TLW

LEADFOOT LOL

i agree with what you are saying but i think i can control; the way i drive

i really dont want to be buying new tires every month loll

so that right there is reason enough for me to be cool and not act like an *** all the the time

plus if i ever decide to sell the supercharger i still have the LSd

i do respect your opinion

rominl

iTrader: (4)

i thought with the 3.76 and fi some people had problem on the rev limiter?

redgs4

I have heard that the 3.76 Torsen was good to about 400 RWHP. The clutch pack LSD's are good for much higher.