CDALTON

I tried doing a search first, but did not find the info I was looking for. I have a SC 400 with a PI TC (3000-3200) range. I want to do the supra swap, but I am not sure what would be the best setup. Is anyone using a locking 4.27 setup or is the common setup a non-locking 3.76. From some of the previous post's I've gathered that some guys were using a non-locking 3.76 supra tt. If someone could shed a little more light on me I would greatly appreciate it. My goal is for better 0-60 times than top end, this is why I was considering the 4.27. Thanks!!!!

mdfdsc300

Chad,
good to see you here on the forum. We met once at Fox Valley. So you went the TC route eh? How do you like it? I'd like to learn more about it. Any noticeable difference from stock setup?
Regards,
Thom
Black SC300

CDALTON

Hey Thom, good to hear from you. I just pulled my car out of storage last weekend. I did the TC in the fall of 2002 a week before she went in storage. The TC works to good!!! I can't get any traction off the line! Thats why I am inquiring about the Supra rear end. I have found rearends used $400-800. I just want to go with the right setup from the get go so im not swapping out gears a month later. Well have to meet up sometime this summer. Drive fast!!!

Lex Luthor

The Supra was never offered with a 'locking' differential, but the Torsen LSD was standard on all 6spd models and optional on the automatics. The stick LSD has a larger ring and pinion as well. So, to answer your question, of course you need the one with the limited slip, otherwise what you're buying is what you already have, kay?

mdfdsc300

Chad,
where did you get the PI TC? where did you get it installed? I may be interested in doing something like that. Would love to see your setup first hand. Let me know what's a good time for you. I ended up going with 18's also.

CDALTON

Thom, I ordered the converter from http://converter.com/dragon.htm. When you order they will ask you what stall speed you want. A mech. friend of mine and myself installed the converter and trans cooler. Thanks for the reply LEX LUTHOR. So I should be looking for a Torsen from a 6spd (3.76). Thom, the next couple weeks are going to be bad for me(trying to sell my house). Mid April will be much better for me.

racing fan

What kind of tires do you have? That should solve your traction problems....

If anyone knows.. Wil teh supra auto(3.73) diff+housing bolt up to an sc300 driveshaft and halfshafts? I know the 6spd needs a different driveshaft and left halfshaft but I somehow got the impression teh supra auto diff is interchangeable with ours....

CDALTON

Whats up racing fan! I have brand new KUMHO Supras with less than 1,500 miles on them (18" x8.5 rims in the rear). I did some more searching and I believe the auto would work on your 300. The auto is a 3.76, and from what I have read the 6 spd is a 3.13. (someone please correct me if I am wrong). The 3.76 auto unit should be a clean swap. I think I am still going to look for a used one from a salvage yard instead of buy a new one. So if there are any other 400 guys out there who have done the swap, give me your feed back, much appreciated. The mods I have that matter are the PI TC (3000-3200) Stall and the weapon-r ecu upgrade. So if any guys running this setup with the upgrade to LSD, could you please share your setup and thoughts after doing the LSD. Have a good weekend guys!

racing fan

THe lsd is gonnaa help with tradtion no doubt!

But an 8.5" rim thats not wide enough... you can fit an 11" wide rim back there!! If you get some wider tires traction should be fixed for ya 275, 285s, 295s, and 315s with a rolled fender if you are lowered

JBrady

I went through a HUGE learning curve on this subject so let me share.

I bought one 1998 Supra TT automatic 3.77 (3.769) geared differential housing. The owner was POSITIVE it was a LSD... nope! Open. I inquired on another from a 97 and asked him to open it and inspect it... Open!!! The 93-96 cars SHOULD be LSD as it APPEARS they change from LSD as standard equipment to optional on automatic TTs happened in 97.

Remember, may of these cars have had their power increased dramatically. Most for sale are off cars either wrecked or where there owners upgraded to the stronger 6 speed housings (larger unit, not easily installed in an SCxxx). The torsen style LSD have been known to break.

I believe the SC400s have close to (if no the same) 3.77s gears already. Going to 4.27s from 3.77s will give you a 13% increase in torque in each gear but that gear will hit redline 13% sooner. If this causes your car to need to shift into 3rd before 60mph you may actually be slightly slower to 60 but the car will FEEL faster and will BE quicker in most ranges. Your speedometer will probably be off and show your speed as 13% faster than is the case.

For these reasons you may be miles ahead by buying a TRD clutch type LSD and having it installed with your existing gears. This will give you a brand new LSD and provide much more off the line traction. With the TC I doubt you will even WANT higher gears. Next step is more power

SC300T

I agree with Jbrady, get the TRD LSD and keep your existing ring and pinion ratios. The only drawback is that differentials are not easy for a novice to take apart---I'd leave it to someone with experience. There is a certain preload on the unit that must be measured and adjusted in order for the unit to function correctly. If you get it wrong there may be issues.

Fred Smith

Stock diff in my V8 Soarer: Open 3.917.
Stock diff in JDM TT Auto Supra: LSD 3.769.
Stock diff in JDM TT 6sp Supra: LSD 3.266. (export 3.13 I think??)

I am looking at getting an auto Supra diff in the short term. Are you guys saying the 6 speed has a different diff that is stronger?? How strong is the auto diff? I have heard of guys with auto mk4s making it into the 5 or 6 hundreds easy? I was unaware of any difference in the auto and manual Supra diffs other than ring and pinion?

Also, if you want a cheap Supra LSD (no casing, internals only) look at Titan Motorsports. I believe they sell them for around 200 USD. I wouldn't worry about a stock Supra diff being able to hold whatever a N/A SC400 can put out... it's used to more.

CDALTON

jbrady and sc300tt!!!! Thank you, thank you, Thank you. I just picked up another 400 rear end this weekend( Plus the drivetrain, ya baby!!). I will buy a TRD LSD and install it in my spare rear end so I won't have any down time. mvpmotorsports.com sells the TRD LSD for $805. Is there a better price out there? Thank's again for the great advise.

Hermosa

Please refer to my earlier thread about differentials.

https://www.clublexus.com/forums/sho...&highlight=lsd