Torsen LSD w/4.27 ring into SC400 (many photos)

[dazz250]

Great job, very meticulous! That is the sort of diff that I wish manufacturers would supply standard on any sports model of car.

Oh, I noticed you boiled the ring gear to expand it to locate it on the shoulder. You could also put the carrier in the freezer for a couple of hours as well as boiling the gear to give you a few extra seconds. (especially worthwhile doing this if it is a hot day)

Again, well done & props for writing such a detailed step by step!

 

[cribbj]

Blizzy great writeup, many thanks for your contribution!

The pic of that diff on the skateboard is a classic.....

Nice Soarer badging on the car too ;-)

 

[Blizzy]

Blizzy great writeup, many thanks for your contribution!

The pic of that diff on the skateboard is a classic.....

Nice Soarer badging on the car too ;-)

Thanks.

From limited experience driving the car mildly, I expect my 45-65 time to drop significantly (perhaps even close to 3). I expect my 0-60 times to be in the 6.2-6.3 range.

The purists do not like that my Soarer badging it not 100% exact to JDM specs; but, I don't care. I cover up the mounting holes for my stock emblems and look OEM at the same time.

100mi of the break-in period have been completed.

The skateboard was instrumental.

 

[StiCk3]

The purists do not like that my Soarer badging it not 100% exact to JDM specs; but, I don't care. I cover up the mounting holes for my stock emblems and look OEM at the same time.

when you mean purists i hope you dont mean the guys over in CL.

Props for using gardening soil as a good diff cushion. Send them over to the CL members so they can dump it into a GTE

 

[Blizzy]

when you mean purists i hope you dont mean the guys over in CL.

Props for using gardening soil as a good diff cushion. Send them over to the CL members so they can dump it into a GTE

I am refering to the Club Lexus guys. Personally, I think my emblem set up looks more OEM than the stock Soarer emblem orientation: it really flows well with the rear end. From that perspective, the car often makes people look twice. I can't wait until I can back it up with forced induction.

Even though I am partial to the V8 (like everyone on this forum), you still have to respect the GTE guys that go all out: 32-35psi on race with 67-80mm turbos absolutely torching the road.

Granted, that is the easy route. Even after I am blown, a BPU GTE may well still eat me for lunch. I am sticking with the V8 mostly because it sounds amazing, mine is in amazing shape, and it will be walking on American V8's cylinder for cylinder.

ps. my break in is over. I will time the car tomorrow night. Having pushed the car a little bit, it feels much lighter or more powerful (whichever way you look at it) under load from the gearing. The perception of additional torque from the gearing is felt.

 

[StiCk3]

I am refering to the Club Lexus guys. Personally, I think my emblem set up looks more OEM than the stock Soarer emblem orientation: it really flows well with the rear end. From that perspective, the car often makes people look twice. I can't wait until I can back it up with forced induction.

Even though I am partial to the V8 (like everyone on this forum), you still have to respect the GTE guys that go all out: 32-35psi on race with 67-80mm turbos absolutely torching the road.

Granted, that is the easy route. Even after I am blown, a BPU GTE may well still eat me for lunch. I am sticking with the V8 mostly because it sounds amazing, mine is in amazing shape, and it will be walking on American V8's cylinder for cylinder.

ps. my break in is over. I will time the car tomorrow night. Having pushed the car a little bit, it feels much lighter or more powerful (whichever way you look at it) under load from the gearing. The perception of additional torque from the gearing is felt.

No disrespect to the GTE at all, in fact i want to do add a turbo to my car at some point just for experience purposes. The only reason i dont like the GTE is that it is so commonplace these days that i want to do something different. Thats what makes the 1UZ so attractive...along with that addictive V8 growl that no GTE can match.....

 

[Blizzy]

...along with that addictive V8 growl that no GTE can match.....

amen to this notion.

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

I just got back from time trials with the 4.27 LSD. Recall my baseline averages are 6.78s for 0-60 and 3.57s for 45-65.

I ran five trials for each. Again, I used the digital camera and trimmed the files using a video editor. For this iteration, I was careful to account for the speedometer error from the different gearing.

Here are the times...

0-60mph:
(1) 6.50s
(2) 6.44s
(3) 6.50s
(4) 6.43s
(5) 6.37s

45-65mph:
(1) 3.23s
(2) 3.17s
(3) 3.16s
(4) 3.23s
(5) 3.23s

This generates new averages...
0-60: 6.45s (-0.33)
45-65: 3.20s (-0.37)

It is noticeably more difficult to hook up off the line with the shorter gearing. However, the LSD does do a nice job of a "chirp and go" launch. I think more practice launching with the LSD could trim perhaps another 0.1s from my 0-60. But, these numbers really give an excellent indication.

Theoretically, the LSD is not giving me any kind of a boost from 45-65 over an open differential. Thus, for $150-200, a salvaged SC300 a/t differential with the 4.27 gearing could net a very nice result for not a lot of dough on an otherwise stock SC400.

 

[Lextreme II]

Good work buddy. Now with a TC you will launch alot harder. How is your rpm in 30, 60 and 90 mph as mentioned in earlier post? Real life recording that is.

 

[Blizzy]

Good work buddy. Now with a TC you will launch alot harder. How is your rpm in 30, 60 and 90 mph as mentioned in earlier post? Real life recording that is.

thanks.

with an R154, I will be launching harder than even a stalled up auto. I am bypassing the TC and going right for the five speed. I have one sitting the garage right now actually.

rpm at 30/60/90 is impossible to be anything other than the theoretical numbers. There is not any play in the gear ratios. They are what they are. With my speedo error, the numbers listed previously will be more accurate than anything I will be able to observe.

 

[sc400injen]

nice write up man, very detailed and pics all the way through, nice. I like the enthusiasm for the 1UZ, i have to say i f**kin love the growl of my custom bent Borla tubes. The next thing i will be doing is changing to an lsd. i have a 92 sc4 and i'm jus gonna put a 93-98' Supra Auto TT rear end on mine. i have a question and any help would be greatly appreciated

does the differential match up for the first gens or is it the whole rear end (including axles)

probably jus the differential, but jus wanna b sure before i go and buy a supra differential,


once again, thanx for the writeup and nice setup with the soarer emblems and keep that clean SC look and the V8 growl


peace mane,

Knowledge

 

[is300ss]

ive been wanting to do the same ewact with my diff that you have did this right up on.

i have a sc300 and a 1jzgte as well it sucks when your cruisin at 80 on the high way ane ur at like 3800rpm but whatever.

I tune myself so im not worried about.
I can make the at a/f at 15.7 till the second it hits boost so i dont mess my up haha. I love tuning... sooo easy. can't believe everyone gets there professionally tuned, especially these toyota motors, they can handle super lean a/f's

yo so i have a question.

What Torsen diff did you buy that goes in there?
thanks for your write up though man. helps a lot

please asnswer me though, im dying here with 14.5 psi and wit one wheel wonder.

 

[is300ss]

DAMN, nice write up man, very detailed and pics all the way through, nice. I like the enthusiasm for the 1UZ, i have to say i f**kin love the growl of my custom bent Borla tubes. The next thing i will be doing is changing to an lsd. i have a 92 sc4 and i'm jus gonna put a 93-98' Supra Auto TT rear end on mine. i have a question and any help would be greatly appreciated

does the differential match up for the first gens or is it the whole rear end (including axles)

probably jus the differential, but jus wanna b sure before i go and buy a supra differential,


once again, thanx for the writeup and nice setup with the soarer emblems and keep that clean SC look and the V8 growl


peace mane,

Knowledge

yeah the whole pumkin bolts up and the axles to. I believe the drive shaft in'st going to bolt up though. in that case you just need to swap that part on the supra diff that bolts to the drive shaft (talk about for lack of technical term) with the one if you sc400 differential. I fogot the part of the tint little shaft im sorry

 

[is300ss]

thanks.

with an R154, I will be launching harder than even a stalled up auto. I am bypassing the TC and going right for the five speed. I have one sitting the garage right now actually.

rpm at 30/60/90 is impossible to be anything other than the theoretical numbers. There is not any play in the gear ratios. They are what they are. With my speedo error, the numbers listed previously will be more accurate than anything I will be able to observe.

Thats what I like to hear!! R154!!

yeah I bet its going to be tough with the torque of that V8.

but how about throttle control instead of traction control!

with my r154 and 4.27 gearing...
80mph - 3750rpm (5th gear of course...)

It's pretty high, but its ok. It will keep me from cruise speeding you know what I mean?
plus I just have it leaned out when im not in boost... it works out

 

[ruishy1]

What is the diff code for the torsen type LSD's ?
is it ao1b, a03b etc.
thanks

 

[spf_lexus]

Im about to pick up an sc400 here and was curious if the entire pumpkin, d-shaft, LSD and mounts from an mkIV supra can swap directly? I plan to do a 4.7l swap in it and like you guys, dont want a one wheel wonder!

 

[fastegg]

torsen LSD

What is the diff code for the torsen type LSD's ?
is it ao1b, a03b etc.
thanks

A01A is open ... A01B is LSD..... the A at the end denotes open and B at the end denotes LSD

 

[fastegg]

1998 LS400 Torsen Unit

WOW!!! That was a great tutorial about changing from an open to a Torsen unit. When i eventually get a torsen unit for my 1998 LS 400 (a torsen or better still a torsen 2 out of a Supra Mk4 auto twin turbo from 1996 up to 2001).... i now know exactly how to do it.... I was going to get a transmission / diff shop to do it but now i have the know how, i'll have a go myself...
Thanks Blizzy, you've just made my day !


1998 LS 400
Bilstien HD shocks
3mm larger diameter K-Mac front sway bar

 

[spf_lexus]

Great writeup Blizzy. I just picked up a stock auto sc300 diff today and plan to install it into my sc400 next week. From your calculations, I dont think i will mind 3000rpm for 75mph. I dont cruise any faster than that anyway. Any idea how much the stock speedo will be thrown off? Or how hard it is to re-calibrate the stock speedo?

 

[fastegg]

LSD conversion

hi mr blizzy..... when you changed from open to LSD, did you have to change the side shafts or were they the same ?.......
... The reason i ask is that when you look at the toyota parts list, they show a different part number for the open to the LSD.......