I'm trying to replace my differential and get rid of the awful open diff. I have a few ideas. I could put in an aftermarket supra diff. I could do a ford 8.8 swap which is doable and inexpensive, a little cheaper than the supra diff swap from what i've seen. Another option, and what seems like my last option is putting in an sc400 diff. I heard that the canadian 400 diffs have an lsd in them. Is this true? If so does anyone know of one for sale or where a good place to look for those diffs would be?

P.S.
I'm planning on runnin 700-800 horses on my sc300, just bought the car a month ago and am trying to stockpile parts so I can start working on in in the spring. Any info would help. I appreciate it!

 

If your goal is 7-800 wheel you'll want KAAZ, Cusco, TRD or, OS Giken for your LSD
How do you want geared? What transmission do you plan on using?
Youre gonna need to rebuild it to install the diff/ring and pinion

I'm looking at t56 close ratio + 3.615 gear from 1st gen LS400 for what I want my car to do

Your toyota/lexus gearing options that are usable in your stock pumpkin I know of are:
4.272 - SC300
4.083 - SC400
3.916
3.615 - early LS400 I think 94 and back
3.266
2.937 - LS460

learned this info from KahnBB6 I took notes on all the gearing that was realistic for me to get my hands on to rebuild my pumpkin with

What are you building your car for?

 

denSC300, welcome! And unless you're building a full dragster there isn't a need to change the entire differential system out for a Ford. These 200mm factory diffs, gears and axles can take a LOT of horsepower and torque.

According to the big differential info thread on SupraForums, yes, supposedly some Canadian SC400's got a Torsen LSD option. My guess is that this was still optional and fairly rare. I've never read about anyone actually finding such a car however. Maybe there just weren't as many Canadian SC's made as there were U.S. SC's?

In any case as ninetwo points out for a 700-800whp build you should skip the rare Torsen LSD entirely. It's great but it's not suited for that kind of power output. His post above gives you all the LSD options. There is also a Russian made LSD that we've recently learned about... which is probably a Quaife ATB clone made to the Toyota 200mm diff dimensions... but there is only a single thread covering it and have to date only been a couple of owners who have actually tried it and reported back about it.

Still, at 700-800whp just go with one of the proven clutch-type LSD options over a geared differential.

....

ninetwo, I added a litle clarification below for sourcing these various ratios. For reference, here is the master source for compatible diff ratio information. Note that in the linked thread there are two differentials references for several world markets: the "Small Diff" (200mm) and the "Big Diff" (220mm, only ever used in the MKIV Supra).

https://www.supraforums.com/threads/...l-info.608545/

What we are concerned with is anything that applies to the 200mm differential system/family in the Toyota and Lexus lineup.

For your own build if you have decided on the Tremec T56 Magnum 6-speed transmission then the ratio that is of more popular choice is actually the 4.272 or 4.083 because of how it is geared. I'm not sure if 3.769 is used by many with that transmission. The 3.615 ring and pinion (sans the diff housing they came from) might make your T56 Magnum setup feel too long unless you've got a good reason to gear it that way.

 

Good catch on the 3.769 Kahn, I skipped it in my notes seeing Japan I guess.
I ended up choosing the 3.615+close ratio after figuring out different highway cruising rpms thru the gears - was advised against this by grannas as it'd feel sluggish, maybe the 3.769 is more up my alley.
This isn't set in stone and I plan on eating a lot more information up before I make any moves

I'm wanting somewhere in between 4-500 wheel for my car, NA-T. I'm not looking for a racecar with it though. Sporty sure, but I also want a nice comfortable ride that can reach high speeds and cruise comfortably if needed. I've always wanted my SC to cruise at a little lower RPM though. Maybe eat a Dodge or two in a roll race.

 

I am actually building my car to be primarily a drift car. I'm gonna use the 350z cd009 tranny. I'm looking for gearing in the mid 3.xx range. I've been considering getting the KAAZ 2 way supra diff. When I called a guy at KAAZ he said that the diff wouldn't be compatible with my pumpkin because my gearing is currently a 4.08. I've been looking around for places that sell 3.769 gearing for my pumpkin so I can fit the supra diff in it but I haven't had any luck. If I were to change the gearing in my pumpkin, what would the process be? Do any of you guys know? Also, do any of you know where I could find the different pinion and ring gear for my pumpkin? Any info helps. Thanks!

 

First of all I can't know how the conversation between you and the Kaaz representative was worded but you should know here and now that as long as the differential was designed for the factory rear diff/pumpkin type that your SC comes with then it doesn't matter what final drive gear ratio it has inside it. You can use any of the compatible ratios listed above and it will not matter for the Kaaz LSD's function. I'm not sure what the representative was talking about.

Now in some cases for clearance there are some *very* minor differences between between the various SC/Soarer/MKIV/GS/Aristo 200mm differentials such that you may need axle stubs from another diff housing (aka differential "pumpkin") in the Toyota 200mm family type... but that still has nothing to do with the ring gear and pinion gear that you would use.

As far as finding the ratio you are looking for, consult the list above and the link on SupraForums in one of my posts above for the mother load of info on the SC/MKIV compatible 200mm "small diff" options. Finding one for sale ranges from the Clublexus Marketplace to SupraForums For Sale ads to searching on eBay to see if the used donor diff with the right ratio is listed for sale there.

As for rebuilding I tend to suggest having a professional driveline shop do the work for you... unless you're experienced with rebuilding and carefully setting all the tolerances correctly with a diff rebuild. I have used Driftmotion's rebuild kit (containing all OEM Toyota parts) and had them rebuild my diff as well as (the now defunct/closed) Speed For Sale in GA. It's going to be a few hundred bucks usually to get one of these diffs rebuilt by a professional but it's worth it to get it done right the first time.

For Kaaz 2-Way diffs and most other 2-way aftermarket clutch type differentials there is almost always a strict break-in procedure that needs to be followed to get the best out of your new clutch type LSD. OS Giken may be the only LSD manufacturer that makes an exception to that.

 

I have a kaaz super q (DAT3020Q) in my 4.08 and I love it. If you got the money go 8.8 cause aftermarket sc axles suck and used replacements are always a gamble. Ive broken them on my stock manual sc300 on A/AA 265 tires, so I imagine 700 on tire capable of handling the launch would take a toll on them.

 

Currently doing a 8.8 swap on my sc300. I opted for the grannas pro kit. Car will make about 850, until I have some time for a billet main motor. With that being said , the diff itself is the cheaper part

$100 for a core 8.8 explorer
$180 for 4.10 final drive
$250 in labor
$150 shipping back and forth
$600 for tru trac lsd
$103 bearings and rebuild kit
$30 axles seals

so like $1300 in the built diff itself , but I should never have to worry about breaking it in the future.