Supra Differential Interchange Guide

limequat · 09-09-2005, 12:05 PM

Why? Because I love you.
Here's a list of Toyota models that have interchangable ring and pinions with the Supra. Playing mix and match will net you any ratio you need between 2.79 and 5.44. Also it appears the MKIV N/A TORSEN could fit with some hammer work.
Please add to the list if I missed something (I'm excluding lexus at the moment. Some nissans interchange too).

figgie · 09-09-2005, 12:08 PM

this is great.

To bad that the toyota 4x4 is not interchangeable as it is smaller than our diff. See the Toyota 4x4 post about changing diff. They have to take off material off the right side to make it fit.

limequat · 09-09-2005, 12:37 PM

Link?

drjonez · 09-09-2005, 12:38 PM

www.mkiiitech.com

i contend the truck diffs will fit....i think fig thinks you're referring to the diff unit when all you're referring to is the ring/pinion.

figgie · 09-09-2005, 01:31 PM

Quote:

Originally Posted by drjonez

www.mkiiitech.com

i contend the truck diffs will fit....i think fig thinks you're referring to the diff unit when all you're referring to is the ring/pinion.

yeah sorry about that. Thinking about the detroit locker or trutrac diffs.. my bad!!

PbXAssassinX1524 · 09-09-2005, 02:34 PM

Wow, 5.44... thats insane. I think I'll stick to me 4.30 for now

Great info tho! Downloaded

limequat · 09-09-2005, 02:45 PM

I don't see why the appropriate electronic lock-up diff wouldn't work. Don't see why you'd want it either

I assume most supra owners are interested in two things if any:
1) Torsen
2) Change ratios on stock LSD

We all know the torsen is available in 1JZ cars, but maybe the 2JZ Auto could be made to fit too. Personally, I'm happy with the clutch pack LSD.

Ratios are something that come up a lot, whether it's fuel economy, acceleration, or trans swaps (we can finally put to bed the myth that 6 speeds "don't fit" because of gearing. Who came up with that nonsense anyway?)
I find comfort in knowing that I could modify my stock diff for anything from a 3.5 to a 4.5 rear just by changing the ring gear! How cool is that?

What's a TrueTrac? Is it disirable over a clutchpack lsd?

tom.supra · 09-09-2005, 03:03 PM

Mmmm... 2.79:1 off the top of my head that should get you to 100kph in first gear and well over 320 top.

drjonez · 09-10-2005, 02:23 AM

good call on the NA/auto MKIV torsen, i'll have to check it out.

truetrac = helical LSD. i have one i might try to throw in....

flubyux2 · 09-10-2005, 08:53 AM

for anyone who auto crosses or even takes corners at high rates of speed and has a tendancy to clip apex's, the Torsen is NOT for them. when the torsen is under load and one of the drive wheels loses contact w/ the ground, all power is sent to the unloaded wheel. the wheel spins and when it touches back down, there is a great possibility that the spider gears inside will grenade. its happened on more than one occasion to Miata Auto-crossers and FD autocrossers, and select FC auto-crossers who have swapped in the Miata/FD torsen unit.

for anyone who likes to go in a straight line, id recommend the 4-runner electronic locking diff. its like an ARB air locker, but its lighter with less complications. switches from open diff to "locked" or "Welded" diff, like a spool. no worries about worn clutch packs or any of that noise.

some say that the 4runner E-diff can drop in, id like to give'er a try at some point, as well as a 3.54 from the 4-runner too. the car would be quite the Roll-monster w/ a 3.54 and 7000rpm shift point

drjonez · 09-10-2005, 10:32 AM

Quote:

Originally Posted by flubyux2

for anyone who auto crosses or even takes corners at high rates of speed and has a tendancy to clip apex's, the Torsen is NOT for them. when the torsen is under load and one of the drive wheels loses contact w/ the ground, all power is sent to the unloaded wheel. the wheel spins and when it touches back down, there is a great possibility that the spider gears inside will grenade. its happened on more than one occasion to Miata Auto-crossers and FD autocrossers, and select FC auto-crossers who have swapped in the Miata/FD torsen unit...

eh, i disagree. the torsen was the best diff i've ever driven....

51Cards · 09-10-2005, 10:51 AM

Great stuff... now how to modify the speedo gearing for all of the above ratios?

Robbman · 09-10-2005, 01:31 PM

Swap drive gears in the transmission...

limequat · 09-11-2005, 06:56 PM

Quote:

Originally Posted by 51Cards

Great stuff... now how to modify the speedo gearing for all of the above ratios?

Crap, now I have to add a new column to the spreedsheet!

limequat · 09-11-2005, 06:59 PM

Quote:

Originally Posted by drjonez

eh, i disagree. the torsen was the best diff i've ever driven....

But you broke it autocrossing, yes?

drjonez · 09-12-2005, 05:08 AM

Quote:

Originally Posted by limequat

But you broke it autocrossing, yes?

i guess? it actually broke when i was just tooling around on the street on R compounds....i rolled into the throttle in 2nd gear and BAM it fragged. i don't think that killed it, i think the casing was cracked earlier and that just did it in....

limequat · 09-12-2005, 06:19 AM

Quote:

Originally Posted by drjonez

i guess? it actually broke when i was just tooling around on the street on R compounds....i rolled into the throttle in 2nd gear and BAM it fragged. i don't think that killed it, i think the casing was cracked earlier and that just did it in....

Eh, you're probably an extreme case anyway.

drjonez · 09-12-2005, 06:23 AM

i don't think so. the T-1 doesn't take kindly towards shock loading....i think any diff in a 3500+ lb car will see a fair amount of shock....we need to look into the MKIV NA/auto torsen....though i doubt it will fit.

flubyux2 · 09-19-2005, 11:32 AM

Quote:

Originally Posted by drjonez

eh, i disagree. the torsen was the best diff i've ever driven....

fair enough. there are plenty of cases where people havent had any issues with the torsen. for a lighter car that can pull the wheels off the ground easier than we can, it may not be the best choice as far as durablility. that would explain why people like you in the MK3's or similar weighted cars dont have the same problems as those with the lighter miata's and FD's.

i agree, a torsen is a superior diff... as long as both wheel stay on the ground at all times.

i prefer either a viscious due to the durability and smooth transition... if i want to drift, id much rather have a clutch LSD though.

and you can get speedo gears from different MK3's, that would put your speedo close to accurate with similarly geared rear ends... but if you get extreme with a 3.23 or 4.90, your SOL.

outofstep · 09-29-2005, 10:25 PM

So anyone try changing ratios?

outofstep · 10-16-2005, 09:30 PM

So.... am I gonna be the first person to do this?

drjonez · 10-17-2005, 04:42 AM

probably. i've got the junk sitting here, but won't be doing anything w/it for a while....

outofstep · 10-17-2005, 01:13 PM

I've got a 3.9 and a 4.3 laying around but swaping pinions/gears in those won't do anything, just give me whatever I've got already. If I had the ring from a 3.7 I could see if I could make a 4.1. Other than that, I don't know of any other rings/pinions that would be easy to get ahold of.

I've got the spare pumpkin just laying around. Just need rings/pinions.

drjonez · 10-17-2005, 01:21 PM

just get a truck ring/pinion....

outofstep · 10-17-2005, 01:39 PM

Is it any of the 8 inch stuff, or just the stuff listed in the PDF though? Only crap I can find on ebay is stuff for the 8 inch.

09-10-2005, 02:23 AM	#9
drjonez boost freak Join Date: Sep 2001 Location: the motor city Age: 4 Posts: 11,374	good call on the NA/auto MKIV torsen, i'll have to check it out. truetrac = helical LSD. i have one i might try to throw in.... __________________ MKIII Technical Information Depot: www.mkiiitech.com

09-12-2005, 06:23 AM	#18
drjonez boost freak Join Date: Sep 2001 Location: the motor city Age: 4 Posts: 11,374	i don't think so. the T-1 doesn't take kindly towards shock loading....i think any diff in a 3500+ lb car will see a fair amount of shock....we need to look into the MKIV NA/auto torsen....though i doubt it will fit. __________________ MKIII Technical Information Depot: www.mkiiitech.com

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09-09-2005, 12:08 PM	#2
figgie backpsi is my batsignal!! Join Date: May 2003 Location: Farmington MN Posts: 5,986	this is great. To bad that the toyota 4x4 is not interchangeable as it is smaller than our diff. See the Toyota 4x4 post about changing diff. They have to take off material off the right side to make it fit.

09-09-2005, 12:37 PM	#3
limequat Dissident Join Date: Jun 2002 Location: Detroit Posts: 1,094	Link?

09-09-2005, 12:38 PM	#4
drjonez boost freak Join Date: Sep 2001 Location: the motor city Age: 4 Posts: 11,374	www.mkiiitech.com i contend the truck diffs will fit....i think fig thinks you're referring to the diff unit when all you're referring to is the ring/pinion.

09-09-2005, 02:34 PM	#6
PbXAssassinX1524 SupraForums Member Join Date: May 2004 Location: NNJ Age: 22 Posts: 1,238	Wow, 5.44... thats insane. I think I'll stick to me 4.30 for now Great info tho! Downloaded

09-09-2005, 02:45 PM	#7
limequat Dissident Join Date: Jun 2002 Location: Detroit Posts: 1,094	I don't see why the appropriate electronic lock-up diff wouldn't work. Don't see why you'd want it either I assume most supra owners are interested in two things if any: 1) Torsen 2) Change ratios on stock LSD We all know the torsen is available in 1JZ cars, but maybe the 2JZ Auto could be made to fit too. Personally, I'm happy with the clutch pack LSD. Ratios are something that come up a lot, whether it's fuel economy, acceleration, or trans swaps (we can finally put to bed the myth that 6 speeds "don't fit" because of gearing. Who came up with that nonsense anyway?) I find comfort in knowing that I could modify my stock diff for anything from a 3.5 to a 4.5 rear just by changing the ring gear! How cool is that? What's a TrueTrac? Is it disirable over a clutchpack lsd?

09-09-2005, 03:03 PM	#8
tom.supra I need a boost :( Join Date: May 2005 Location: Canada Posts: 106	Mmmm... 2.79:1 off the top of my head that should get you to 100kph in first gear and well over 320 top.

09-10-2005, 08:53 AM	#10
flubyux2 Madd Tyte JDM yo ® Join Date: Jun 2002 Location: Spring Hill, Fl Age: 29 Posts: 5,181	for anyone who auto crosses or even takes corners at high rates of speed and has a tendancy to clip apex's, the Torsen is NOT for them. when the torsen is under load and one of the drive wheels loses contact w/ the ground, all power is sent to the unloaded wheel. the wheel spins and when it touches back down, there is a great possibility that the spider gears inside will grenade. its happened on more than one occasion to Miata Auto-crossers and FD autocrossers, and select FC auto-crossers who have swapped in the Miata/FD torsen unit. for anyone who likes to go in a straight line, id recommend the 4-runner electronic locking diff. its like an ARB air locker, but its lighter with less complications. switches from open diff to "locked" or "Welded" diff, like a spool. no worries about worn clutch packs or any of that noise. some say that the 4runner E-diff can drop in, id like to give'er a try at some point, as well as a 3.54 from the 4-runner too. the car would be quite the Roll-monster w/ a 3.54 and 7000rpm shift point

09-10-2005, 10:51 AM	#12
51Cards SF in my veins... sigh Join Date: Aug 2002 Location: Toronto area Age: 40 Posts: 1,587	Great stuff... now how to modify the speedo gearing for all of the above ratios?

09-10-2005, 01:31 PM	#13
Robbman SupraForums Member Join Date: Jun 2004 Location: VA Age: 33 Posts: 621	Swap drive gears in the transmission...

09-29-2005, 10:25 PM	#20
outofstep Senior Member Join Date: Oct 2001 Location: grape soda Age: 10 Posts: 1,010	So anyone try changing ratios?

10-16-2005, 09:30 PM	#21
outofstep Senior Member Join Date: Oct 2001 Location: grape soda Age: 10 Posts: 1,010	So.... am I gonna be the first person to do this?

10-17-2005, 04:42 AM	#22
drjonez boost freak Join Date: Sep 2001 Location: the motor city Age: 4 Posts: 11,374	probably. i've got the junk sitting here, but won't be doing anything w/it for a while....

10-17-2005, 01:13 PM	#23
outofstep Senior Member Join Date: Oct 2001 Location: grape soda Age: 10 Posts: 1,010	I've got a 3.9 and a 4.3 laying around but swaping pinions/gears in those won't do anything, just give me whatever I've got already. If I had the ring from a 3.7 I could see if I could make a 4.1. Other than that, I don't know of any other rings/pinions that would be easy to get ahold of. I've got the spare pumpkin just laying around. Just need rings/pinions.

10-17-2005, 01:21 PM	#24
drjonez boost freak Join Date: Sep 2001 Location: the motor city Age: 4 Posts: 11,374	just get a truck ring/pinion....

10-17-2005, 01:39 PM	#25
outofstep Senior Member Join Date: Oct 2001 Location: grape soda Age: 10 Posts: 1,010	Is it any of the 8 inch stuff, or just the stuff listed in the PDF though? Only crap I can find on ebay is stuff for the 8 inch.