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Discussion Starter · #1 · (Edited)
I found a gutted 86 turbo at a local junk yard today and much to my suprise the LSD was still there, I'm planning on getting it right after newyears. so i have a few questions.

first" are there any special mounting brackets that i need to take off W/the LSD that wouldn't be on an Na W/out an LSD? Both cars are 86's (Turbo prod date was Dec 86).

second: according to the chart; i now have an non LSD with a 4.10(oops 4.30) gear and the LSD im getting has a 3.91 gear. how big of a difference will that 0.39 make.

and third: is it possible to take the 4.10 out of my diff and put it in the LSD instead of the 3.91?

if there is a thread already covering this please send me a link {i came up with 35 pages of threads when i did the search(for LSD) and am slowly going through them}.

anyway thanks in advance
keith
 

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Republican
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Yes, please explain! I am getting a 4.10 lsd......
 

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Dr Wheelspin Rh.D.
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There were no 4.10's in the Mk3 Supra. A Dec 86 car is considered an 1987 car.

1 - no, just the LSD

2 - You're actually going from 4.30 to 3.91, it's a significant decrease in acceleration but you'll be able to cruise on the highway much better. If drag racing is your thing then forget the 3.91 and keep looking for a 4.30 LSD. You'll find the 4.30 LSD in a N/A with TEMS, you can pull it out of a 5spd or auto it's the same 4.30.

3 - Not that I know of
 

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I did this swap on my old 86.5 NA. I went from the G284 (4.30 open) to the G315 (3.909 LSD). It makes the car feel even more sluggish in 1st and 2nd, but 3rd and above, it actually felt faster. It always felt overgeared in the top gears with the 4.30, IMO. The traction was vastly improved, and my highway mileage jumped 2-3mpg better.

PS there is a Mk3 with 4.10 gears, just not in the US. The 2.5TT's with 5-speed have a G299 axle (4.10 torsen)
 

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Discussion Starter · #6 ·
oops! my bad. bishop is correct mine is a 4.30 open gear (g284).
I bought the car more for touring than racing but.... N/a or not it IS a Supra. Hmm tough choice, Supra junkers are few and far between here and the diff is $100.00. hmm


anyway, thanks for the responses.
 

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Dr Wheelspin Rh.D.
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PS there is a Mk3 with 4.10 gears, just not in the US. The 2.5TT's with 5-speed have a G299 axle (4.10 torsen)
Since this is a USA run website with 95% of the readers in the US or Canada I like to only list USA options. If I had to list Japan and UK options in every post it would get annoying quickly. I know all about the Torsen but since it's near impossible to get them in the states there's no point in listing it :)
 

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Bishop92T said:


2 - You're actually going from 4.30 to 3.91, it's a significant decrease in acceleration but you'll be able to cruise on the highway much better. If drag racing is your thing then forget the 3.91 and keep looking for a 4.30 LSD.

How about holding 1st longer? My 82 had 3:73 with only 160 torque. 0-100 took forever!
 

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How do you get your speedo to show the correct speed after the gear change?
Is there a gear in the trans you change or is it programmable or ??
Thanks
 

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Discussion Starter · #11 ·
yes, what about the speedo gear. this car is an auto and mine is a 5spd. i haven't even thought about that yet.
 

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Fuzz E. Guy
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and third: is it possible to take the 4.10 out of my diff and put it in the LSD instead of the 3.91?
Actually this can be done. It involves removing the ring gear and from the open differential and installing it on the LSD. When I replaced my clutch pack LSD with a Torsen LSD I also changed from a 3.91 gear set to a 3.73 ring and pinion set. I dropped my differential carrier and opened it up. I removed the differential , ring gear and pinion. After cleaning and repainting the carrier I installed a Torsen LSD. The Torsen came without any gear on it. I used a 3.73 gear set from a second differential I had bought.

Check out this section of the TSRM

Differential
 

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Discussion Starter · #13 ·
i hate to sound iggnorant, but i am, so.. What is a torson? Is it like a name brand like dana or is it a type of rear end. i see where Sabolt says he went from a clutch pack to Torson.
does this help me in going from my stock toyota diff to a stock toyota (Clutch pack?) LSD? I've never pulled either apart and probably wouldn't know the differences until someone showed me.
thanks for the TSRM link
 
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out of curiosity....
is it possible just to swap out the final gear and still keep the lsd on the turbo cars?

melloboy
 
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