LSD for JZA80

[JustCallMeOrlando]

Hey all,

As many of you know, I finally picked up my JZA80. Nice car to drive, but it could definetly do with an LSD. I just want to know what my options are.

Of course, I'd like a straight swap so only suggest if you know. Part of the reason for this thread is that not all of the information I've found has been consistent.

Now, I am a fan of a Torsen. The XX has a Truetrac and I love it.

Plans are for supercharged 1UZFE w/ Tremec TKO, with an interim stage of 1UZFE w/ W58. The simplest option would be to find an LSD from a NA Mk4, which would mean a 4.083:1 diff and Torsen. This may be a bit buzzy for my daily driver with a 1UZFE though.

An alternative I'm needing a little info on is an auto TT or a manual SZ-R (with 6-speed) which come with a 3.769:1 diff which may be suitable. Is this correct?

Last option I know of is a B-series 3.2:1 from a manual TT, but this would be a dog to drive until I got the 1UZFE supercharged.

Is this information correct, have I missed any options? Are any of the XZZ3X Soarer diff's suitable?

Cheers,
Nathan

[Norbie]

Looks mostly correct, except that not all RZ's have a B series diff, only the early ones. At some point (96?) they switched to the smaller A series, still 3.2:1 ratio though.

A Soarer diff will certainly fit, but not sure about driveshafts. I keep hearing people talking about swapping the LHS driveshaft when doing an LSD conversion, that might only apply to the bigger B series diffs though?

[ed]

soarar z30 gt ltd a series lsd diff swaps straight in, no half shaft issues
good luck finding a wrecked na mkiv A series lsd though (same diff)

its the b series that has the different size output halves, and will require some 'open mindedness' to recreating correct half shaft lengths. avoid if possible

im assuming your car has the 4.08:1 in it already nath?

if so, the 1uz will have approx the same rpm and power band as the 2jz, whats wrong with that ratio?

whats the tremec ratios for comparison?

i doubt youll find need for anything larger than the 3.769 if that even fits - cant help there. ps- dont believe a hunk of babble on supraforums. its all confusing ass wiperage time wasting info. get an EBC and just look it up

A series swaps straight in. B series doesnt without new half shafts

[JustCallMeOrlando]

im assuming your car has the 4.08:1 in it already nath?

if so, the 1uz will have approx the same rpm and power band as the 2jz, whats wrong with that ratio?

That's okay for the 1UZ methinks but when I stick the supercharger on I don't think its going to be very useful.

whats the tremec ratios for comparison?

Dunno offhand. I'll find them out. bit taller from memory.

i doubt youll find need for anything larger than the 3.769 if that even fits - cant help there. ps- dont believe a hunk of babble on supraforums. its all confusing ass wiperage time wasting info. get an EBC and just look it up

Why do you think I'm asking here? I think the 3.769 would be good. What ratio was that Soarer one you were talking about?

[ed]

soarer 4.08 uzz31 gt ltd a series lsd

bit taller is good, can get away with slightly lower diff ratio than otherwise

if the engine has the same operating rev range and ballpark powerband, the diff will be fine taller ratio for load and spool i can understand (these days!) doesnt hold for sc

[EldarO]

what about artistoes? what diffs do they run?

[manny]

Ed
Just to clarify, JDM MK3 Soarer diff ratios:
UZZ30/UZZ31/UZZ32 ran a 3.92:1 diff ratio
JZZ30/JZZ31 ran the 4.08:1 diff ratio

[JustCallMeOrlando]

I'm more thinking that with a shorter diff and the s/c it may just be wheelspin city.

Aren't there differences between the auto and manual ratios? one of the Soarers I thought had a 3.769

[manny]

I'm more thinking that with a shorter diff and the s/c it may just be wheelspin city.

Aren't there differences between the auto and manual ratios? one of the Soarers I thought had a 3.769

No difference on the JZZ30 Soarer between AT or MT diff ratios - axle code for both is either A02A (open centre) or A02B (Torsen LSD).
3.769:1 is one of the MKIV Supra ratios, TT with autobox if memory serves me right

[Norbie]

Aristo is also A series so "should" fit, but they're not exactly thick on the ground just yet!

My Aristo front cut had a A01A axle code, not sure what that translates to.

[ed]

a01a = open, lazy gearing

what nath has already

fwiw, my wrong, i thought my diff was a 4.08, but its a 3.91 torsen from a uzz31

[ed]

[JustCallMeOrlando]

Tremec TKO ratios for reference:

2.87 - 1.89 - 1.28 - 1.00 - 0.64

They're quite tall, so it might not be as bad as I first thought. I still think the 3.769 would be a good compromise, but then I need to work out where to find one.

mkiv.co.nz has it listed against a V160 equipped SZ-R and an auto TT. Question is, is the auto TT diff an A-series or a B-series?

[MR 1JZ]

why not just get a 1.5 way LSD and swap out the open centre you currently have

they are cheap on nengun atm

[Norbie]

mkiv.co.nz has it listed against a V160 equipped SZ-R and an auto TT. Question is, is the auto TT diff an A-series or a B-series?

I'm pretty sure only the RZ (6-speed) got the B series but I can't confirm.