Reesetrict

iTrader: (1)

My SC400(2jz/R154)is currently rocking its stock open 3.913 diff and I just bought a 3.266(GS400) with a torsen. Does anyone have experience with a mid-high hp SC, through a 5spd, and a tight geared diff like the 3.2? Ill probably end up playing around with it, but I wanted to check and see if anyone has experience. I have a feeling the 3.2 will have me living at the rev limiter, but thats just conjecture. Anyone using the 5spd with similar power through an LSD and a 3.9?

trufanatic

On the r154, a 3.77 soarer or aristo rear end would have been perfect. The 3.2 is going to be a funny experience being so low geared i would believe

megamax

iTrader: (9)

is this gs400 a lsd??

trufanatic

the 3.2 rear to the best of my knowledge never came with the option for LSD. 750 through an r154 tho is questionable. Is it an original soarer box?

Reesetrict

iTrader: (1)

No, its an auto TT torsen that is installed in a GS400 pumpkin, as megamax assumed. The R154 is packed with marlin crawler internals, so its as good as its going to get. When it lets go I guess Ill just have to get a V. Until then Ill just rock the R. I feel like everything on my car is limited by the R... Sucks. My Precision 6766 BW BB blowing past 2000ccs spraying E85 can definitely make more.... but I got a deal on the R. Also, block is stock. none of you guys has experience with a 3.1 or 3.2 though a 5spd? The 3.9 is good, but since its all I know, and open, no less, I was curious to see what everyones experiences were. I have a feeling it is going to be exponentially more fun with 2 wheels spinning.

Reesetrict

iTrader: (1)

Trufan, I just noticed you have a similar setup. What diff are you running? LSD?

account2x

iTrader: (5)

TORSEN LSD is a bad idea at that power level which is why most Supra owners goto the TRD LSD.

trufanatic

WAS running a similar setup. But like yourself i was on the sc400 open diff. It isnt too bad, goes into boost quick because of the gear ration but top end and gas mileage suffers tremendously.

I forged and built my motor and decided for the 800hp range the r154 would become a liability and just dangerous so i went with fresh v160, 3.2 rear TRD LSD.

Listen to this man. If you've stepped up to something like a twin disk to help the r154 hold power, you'll worry more about torque breaking everything else behind the motor.

In my case the v160 is notorious for not breaking but breaking everything else behind it.

armyastro

i had a stock tt auto supra diff in my sc300 drag car, ran it for over 2 seasons at over 1000hp through a transbraked powerglide and slicks. never a problem, might have been lucky though and when you are staging in a drag built auto you normally have your driveline meshed tight unlike the slamming in manuals. i ran 9's all day and changed the ams oil in it and never had metal on the magnet
if the gearing is what you are worried about you can swap most of the gear sets out and change it. i have a few extra ones here from 4.1-3.7's. just make sure you measure endplay gap and gear mesh and shim accordingly or you will be doing it all again

99SC42

iTrader: (44)

3.26 came LSD in the JDM MK4 with V161.

Reesetrict

iTrader: (1)

Id actually wager that most supra owners go TRD bc its a 2 way cluch style LSD and doesnt have a tendency to pull to the right in hard, straight line acceleration... without regard for the advantages for a torsen in corner acceleration. It is a stronger unit, no doubt, but I havent read many threads about sheared stock LSDs. My clutch is the new SP/CM full face that is so touted by the MKIV crowd. Im one of only a few that has it in a R154 atm. Its strong. My driveshaft is a 1 piece aluminum. I still think the weak link is going to be the tranny.... not the torsen.

99SC42

iTrader: (44)

Weak Link is going to be the Tranny and the Clutch...i have been there it's alot of hassle when you starting throwing power to that trans with a Single Disc Clutch.

GL

lexforlife

iTrader: (7)

3.77 is the best gearing suited to a r154 .. 2nd and 3 rd gear become useful again and cruising at 80 is in the 2700-2800 rpm range .. but man does it make for a ungodly long 3rd to 4th gear pull ..

blackkarma

iTrader: (1)

I cant really tell you about the diff since i havent slapped my setup together in my sc yet but I can tell you about the r154 being i have ran many of them in my supras. At that 700-850 range a r154 can hold up if you make a few internal changes in the right spots. Now most people will tell you theres no way but after destroying a few, theres a few tricks you can do during a rebuild to keep the tranny surviving. So far a buddy of mine who is making 800+ and drives the car like an animal has managed to keep his r154 up and in good shape for the last 8 months. Still in the trial and error phase so i cant say it will last forever but nothing ever does. The great thing about having a sc is you have the v160 on the mkiii's we arent so lucky.

Reesetrict

iTrader: (1)

Have you read about the SP single disc of which I speak? Everyone says its the greatest thing since the tilton at a fraction of the cost. It cant hold as much, but 800 whp doesnt seem to be a problem in MKIVs. Engagement is super smooth, almost stock. To be fair, I dont do redline dumps. I have this problem where I visual what is actually happening when I do things with my car. I dont leave the clutch pushed in when I come to a stop and I will pull the car out of gear in the sweet spot unstead of depressing the clutch to get it out of gear. I want to minimize the chances of walking the crank as much as I can. The thought of fusing my clutch to my flywheel is not appealing. I just need a clutch that can handle highway pulls and occasionally embarrassing the exotic I manage to coax into some stop light action.

Blackkarma, care to elaborate on these "tricks" you speak of? I presume you are talking about things other than marlin crawler parts.