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Discussion Starter #1
I've searched through the forum, but haven't really found any information regarding this.

Basically, I'm trying to upgrade my car, and one of the things on the line is to upgrade the final drive ratio to 3.2 of the 6Speed TT cars.

Originally, I'd thought it'd be a simple upgrade of swapping the original crown & pinion of my current 3.8 to the 3.2, however, it appears that according to some of the tuning houses I've visited here in Japan, that the LSD itself is smaller. Unfortunately due to my broken Japanese, I'm not really sure which parts are smaller of if they're referring to the whole thing as a unit.

So here are my questions for those who know.

If I get the final gearing AND an LSD to fit the final gearing, will it fit into the original LSD casing? Or do I also need to get a different one for that too?
If so, what other parts will I need apart from the axels going to the wheel and main centre drive axel thingy?

Cheers for any help.
Basically I'm going to try and work out if it's cheaper to by it seperately (which it may be, I live in Australia after all. ~_~) or if I should just buy a second hand full set (if I can even find one).
 

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The 6 speed and the 5 speed differential housing are different sizes. The 6 speed diff will not fit in the 5 speed housing. You could swap the entire housing but you will need to get new axel shafts as they are different sizes as well and a custom drive shaft made as that is also a diffent length compared to the NA. Your best option may be to swap in a TT automatic Differential as they are the same size. This will give you an LDS unit and lower the gearing slightly.
Personally I went with a TRD LSD unit and kept the 4.27 gearing. Not a great top end but the hole shot is nice.
 

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It will not fit the casing. Your best bet will probably be to get a used pumpkin and axles, then custom a driveshaft. Are you sure you're not overgearing the car with those ratios though?
 

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Discussion Starter #5
Not really, At the moment I have an SZ-R 97 model from Japan. It has the 6 speed in from factory and have had several sources confirm it's the same gearbox as the TT's (even Toyota agrees). I'm looking at fitting the TT engine in the next month, but want to make sure I do this correctly. I also won't feel comfortable putting my new 320KPH speedo in unless my car can actually do that.

The other thing is that in Japan, the Auto diff was the same as the diff in the NA's, except with the slightly longer ratio (the same I have there now, which is also standard).

When I bought the car, the idea was to get it as it is now, and work it up to a new engine. As it is, it's fitted with the Torsen LSD, which I'm happy with... But like I said, gear ratio is wrong for it.

At the moment, I don't mind spending the extra money on the new drive shaft, which isn't too expensive getting it done where I am anyway.

I guess you could say it's want to need the LSD of the TT.

My other option is finding a 89 M535i LSD from Switzerland, which has an LSD with a ratio of 3.15... Fairly close.

Uh, it's all so hard. ^_^' Buying this car is like the best and worst of both worlds. ~_~
 

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Discussion Starter #6
Cheers Rabid Child! That's an awesome link. Helps me more then you know. ^_^
 
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