Tech Question, MKIII Diff + MKIV JDM 3.26 Gearset

[Evilempire1.3JZ-GTE]

Does Anyone know if I could swap the ring gears out of a JDM MKIV TT 6 speed diff (200mm) into a MKIII LSD 8" diff (200mm)

From houres of searching the web there is little on this but it makes it sound very possible!

So if I went to an import shop & found a JDM MKIV TT 6speed diff I could put the internals into the MKIII to get the same gearing?

 

[tissimo]

I dont think the mkiv 6spd diff is a 200mm ring gear? at least the 6spd pumpkin is bigger then the auto (assume larger ring gear). But I'm 99.9% sure it wont work.

 

[tturnpaw]

You would need to swap pinions also. You can always measure.

 

[IJ.]

If it could be done it would be common knowledge about the forums.

 

[lagged]

go search on SF some one in the past two months modified the rear sub frame to bolt up the mkiv diff.

 

[Jostar]

Does Anyone know if I could swap the ring gears out of a JDM MKIV TT 6 speed diff (200mm) into a MKIII LSD 8" diff (200mm)

From houres of searching the web there is little on this but it makes it sound very possible!

So if I went to an import shop & found a JDM MKIV TT 6speed diff I could put the internals into the MKIII to get the same gearing?

Ask Jawsgear, SOmeone was looking for that 200mm 3.26 to try & see if it fits on the MKIII carrier... It be very nice if it fit..

 

[Jeff Lange]

93-96.5 JDM MKIV 6-speed TT's had 220mm ring gear
96.5-02 JDM MKIV 6-speed TT's had 200mm ring gear

USDM always had the 220mm in the 6-speed cars.

I doubt it will fit the G-series housing from the MKIII, as the newer style Toyota housings are quite a bit different, but I could be wrong.

Either way, YES, there is a 3.27:1 200mm Toyota ring & pinion set.

Jeff

 

[Jostar]

93-96.5 JDM MKIV 6-speed TT's had 220mm ring gear
96.5-02 JDM MKIV 6-speed TT's had 200mm ring gear

USDM always had the 220mm in the 6-speed cars.

I doubt it will fit the G-series housing from the MKIII, as the newer style Toyota housings are quite a bit different, but I could be wrong.

Either way, YES, there is a 3.27:1 200mm Toyota ring & pinion set.

Jeff

Can someone please send this link to Jawsgear? He know this kinda stuff...

 

[mechanix0889]

i had inquired about this over at supraforums and it wasnt jaws gear that did it...it was vijay from big daddy performance he modified his factory subframe ti take the mkIV differents assembly i had talked to him personally to discuss with him about this due to my 2jz swap i did in my mkIII with the 3.93 lsd rear end.

the mkIV ring and pinion can not be mounted in the mkIII pumpkin as far as i know and what all research i have done.

Can someone please send this link to Jawsgear? He know this kinda stuff...

 

[suprahero]

I know it's not the same, but you can get a 3.51 gear set from Jawsgear that will fit your MKIII rearend.

It might be a 3.59, I can't remember.

 

[Evilempire1.3JZ-GTE]

At last, some solid information, specifications & facts on the JZA80 Supra rear differential.

All information on this page refers to the JDM JZA80, export Turbo JZA80's with the 6 speed ran the B series differential with a 3.133 ratio.

All VVTi JZA80's ran an A series differential, including the 6 speed Turbo from the factory - it was never offered with a B series.

There are 2 differential sizes in the JZA80, the most common is the A series which runs a 200mm crown wheel which was found in the 2JZ-GE manual and automatic as well as the 2JZ-GTE automatic and in the manual 2JZ-GTE from 5/96 up until 7/02 when the JZA80 was no longer produced. The following ratios are available for the A series diff - 3.266, 3.769 & 4.083.

Then there is the B series which runs a 220mm crown wheel. It was found in the 6 speed 2JZ-GTE from 5/93 up until the 5/96 where it was discontinued and replaced with the smaller A series. There was only ever 2 ratios offered on the B series diff - Export JZA80's received the 3.133 whilst the JDM ran a slightly shorter 3.266 ratio.

Both of the A & B series run a Type 1 Torsen differential up until the 5/96 when the Type 2 Torsen was introduced. Information, specifications can be found in the following Technical documents from Zexel Torsen.

Torsen Type-1 Technical Sheet
Torsen Type-2 Technical Sheet
Torsen Performance Technical Sheet
Torsen LSD - Traction Control Article




--------------------------------------------------------------------------------


B Series dimensions.

Differential Case OD 133mm
Element Gear Length 61.90mm
Spur Gear OD 36mm
Worm wheel OD 33mm
Side Shaft OD 37.80mm
Side Shaft spline count 35


--------------------------------------------------------------------------------

A Series dimensions.

Differential Case OD 123mm
Element Gear Length 57.1mm
Spur Gear OD 33.3
Worm wheel OD 30.5mm
Side Shaft OD 33.70mm
Side Shaft spline count 30

Is this enough information so for sure it cant be done right ?

sourced from http://www.turbosupras.com/pages/pages/technical/jza80/Differential%20specifications.htm

 

[Jeff Lange]

Need the dimensions for the G-series 8.0" in the A70 to compare.

Jeff

 

[a_sesshoumaru]

what happened here? why this thread died? how is the 3.51 final drive that jawsgear sells? would it be good to improve 1st and 2nd?

 

[honestabe]

Switching to a higher gear ratio would mean less bottom end but higher top end. So your launches would suffer but your freeway cruising would be improved.

Doward is selling a 0.66 5th gear for the R154 on a side note, so if you want greater top end this would be an option.
http://www.supramania.com/forums/showthread.php?t=98242

 

[rwd]

is it real to say ; if the gear ratio is smaller ,the turbo spool up faster due to extra effort .

I actually have 4.1 torsen , if i change it for 3.26 or something like that , do my car still have good launch?

and when you change gear ratio on mk3, how the speedometer can work?

 

[Jostar]

is it real to say ; if the gear ratio is smaller ,the turbo spool up faster due to extra effort .

I actually have 4.1 torsen , if i change it for 3.26 or something like that , do my car still have good launch?

and when you change gear ratio on mk3, how the speedometer can work?

You will not have a good launch unless you have real high HP & high RPM to launch... switch to a 3.73 ratio...Now that is perfect for a turbo supra..:naughty:

 

[rwd]

You will not have a good launch unless you have real high HP & high RPM to launch... switch to a 3.73 ratio...Now that is perfect for a turbo supra..:naughty:

you think my 4.1 is too big (i have 1jz gt4088 540whp)

 

[honestabe]

you think my 4.1 is too big (i have 1jz gt4088 540whp)

I wouldn't recommend launching on that TorSen, they are prone to grenading upon launch, especially with that level of power. The diff you have all depends on what kind of driving you do. If you do the 1/4 mile, I'd recommend the 4.30 LSD since it's the shortest of the gearing (faster accelleration, lower top speed, shifting sooner). If you do a lot of highway driving and do mainly freeway pulls I'd go for the 3.73 LSD since it'll increase your top end, reduce RPM's at the same speed (compared to the 4.10 or 4.30), and increase the amount of time you're in each gear.

 

[Evilempire1.3JZ-GTE]

I think you are all mixed up.

3.26 is ideal for the V160 or V161 6 speed.

4.3 is perfect for a high reving engine that haves top end power stop & go traffic little freeway driving gets better millage for city driving 4.3 is good for 5000+ rpm revs 280-450hp 1jzs.
The down side to a 4.3 is poor revs & gas millage on freeway drives.
If you have more then 450hp you go through the gears way to fast to actually use the hp to the wheels.

3.7 just kind of sucks for performance but on the plus side if you have a lot of torque and hp it wont matter you could make more use of the gears since it will overcome gearing with hp & tq. It is perfect for freeway pulls and you will get great gas millage on freeways.
The downside to the 3.7 is less gear overlap not as close of a gear ratio so if you have a really laggy turbo or low end weak engine you wont hit spool in a lot of the beinings of your shifts you will also get lousy millage with the 3.7 in city driving.

So the end all most perfect all around gear ratio for the R154/W58 is 4.1 but since the torsens tend to explode on hard launch the next best thing close to first place is the 3.9

The only reason I would go 3.2-3.3 is again for the V160

 

[rshn117]

..do the 1000+ hp guys run the factory torsen in their mk4s?