Differential cooler on J-specs

Hi guys,

Soon I'll be searching for my first Supra. The plan is to enjoy it for a while, then go BPU, and then eventually a single turbo.

It looks like I should go for a J-spec since they're easier to get hold of, cheaper and generally in better condition than the UK models, but I'm concerned about the lack of a diff cooler.

Surely with 500hp or more going through the diff it needs a good cooling system?

Are there aftermarket diff coolers that can be fitted to the J-specs or is it usually the case of retro fitting a UK spec diff?

I've seen quite a few of you are running high powered Supras, how have you approached this?

Cheers

Hi

I ain't no expert but I think the diff cooler is only appropriate for long periods of high speed driving like on autobahns and stuff, to extend the life of the diff. UK roads would probably never warrant the need. I am sure someone will correct me on here if I am wrong.

I have run over 600hp through my j spec Torsten diff for 18 months without any problem. Most high powered Supra's normally have or want a large case uk spec but they are getting rarer and are expensive. But as said you can get away with a small case jspec for normal road use but should consider upgrading to a TRD or similar if you want to drag or track race it

Never had any issues in 10 years of ownership running 550hp in HK in ambient temps up to 40C.

Thanks for the replies, they're really helping me decide between a UK and a J-spec.

Jcbt and Nic, are those hp figures at the wheels? Is the Torsten diff OE on the J-specs?

Whifbitz site is really helpful, it looks like they list all the parts needed for the TRD diff - http://www.garagewhifbitz.co.uk/index.php/toyota/supra/diff-gearbox-axle/trd-896.html

Mine's estimated flywheel HP.

See FAQ section here for differences between Supra models/years http://www.mkivsupra.net/vbb/showthread.php?59334-Supra-Guide-and-Model-Differences-Chart

Ideally you want the larger B diff (left) which is the stronger of the 2 options. The larger diff was fitted to all pre-facelift J-spec 6spd TT's and all UK spec Supra (the UK Supras got the added diff cooler), all other Supra models were fitted with the smaller A diff (right). The standard LSD is nothing special, the TRD LSD is a huge improvement, TRD make LSD's for both size diff casings.

http://img210.imageshack.us/img210/2994/supravsoarerex8.jpg

Thanks for the replies, they're really helping me decide between a UK and a J-spec.

 

Jcbt and Nic, are those hp figures at the wheels? Is the Torsten diff OE on the J-specs?

 

Whifbitz site is really helpful, it looks like they list all the parts needed for the TRD diff - http://www.garagewhifbitz.co.uk/index.php/toyota/supra/diff-gearbox-axle/trd-896.html

jcbt's is 607 flywheel bhp, which works out around 515bhp at the rear wheels.

Thanks guys, and really useful information there Nic.

Nic, just to clarify, are you saying that ideally you want the larger OE diff because it can more likely handle the power? Or because the larger diff casing is already in place which means you can fit a larger aftermarket diff?

Whifbitz lists 2 TRD diffs, one for the 6 speed (http://www.garagewhifbitz.co.uk/index.php/toyota/supra/diff-gearbox-axle/trd-896.html) and one for autos and VVTI (http://www.garagewhifbitz.co.uk/index.php/toyota/supra/diff-gearbox-axle/trd-896-3663.html)

The first is a replacement for diff B in the picture and the second for diff A?

Whifbitz states that the second diff I linked is a replacement for cars with VVTI, which are all facelifts as you said... it's starting to make sense now.

Really appreciate your help

The larger diffs are stronger, but I'm sure there're quite a few members running high hp levels with the smaller diff without issue.

Larger B Diff

J-spec pre-facelift (93-96) 6spd TT

All UK Supras (93-96) auto and 6spd + diff cooler

Smaller A Diff

J-spec facelift (96-02) 6spd TT - there was a period between May 96 to Sept 97 when the facelift Supra was still fitted with the non-VVTi 2JZGTE, not sure exactly when the switch over to the smaller diff happened, would need to check the EPC. If you were looking at a particular car the Axle code on the VIN plate will identify which diff is fitted.

J-spec auto TT (93-02)

J-spec NA auto and 6spd (93-02)

41301-JA800 TRD LSD - Larger B diff

41301-JS402 TRD LSD - Smaller A diff

Thanks mate