the differential does more than just turn the wheels. people spent thousand dollar swap differential to get the car faster. read this and you might understand better http://www.z1motorsports.com/PDFs/TT...earendswap.pdf . i'm not a smart guy . i just wants to share about stuff that i know.

well he was pretty much right...though the top end part i did not know, but wut he said about putting power to the ground is correct, since thats what a diff does and allows the wheels to turn, the diff just makes it easier to transfer the power to the wheels without losing it all through lost traction

Well your talking about converting a single wheel turning diff to a LSD(aka limited slip diff) or a ATB(aka automatic torque biased diff). These diffs are also bullet proof none the less. Your stock gears are much more brittle than a forged diff. So when you get a cusco, or a quaife you are able to downshift at higher rpm's much more smoothly and effortlessly. And they make both wheels turn at the same rate. Stock diffs do not do this. This is why they cost so much. You are paying for precision machining and anytime you deal with that your talking some coin. I payed all together with instalation and new spider gear about 1500 for my quaife diff. And it was money well spent.

So again, the transmission transfers power(hence the terminology trans-mission) its mission is to transfer power. And the differential just takes that power and turns the wheels. I guess you could say its transfering power from the tranny to the ground but the tranny doesnt create power it just transfers it. Now the correct analyzation would be that the diff distributes(not transfers) the power to the wheels. I hope that helps a little.

distributes...transfers....same idea...but yea....putting in a quality diff is not gonna be cheap

Actually they mean completely 2 different things. So they arent the same. But I understand why someone would be confused because they are somewhat similar.

Hell, I'm a brand newbie on this board and I plan on buying a supra TT in a couple of years.


However I am not a newbie in mechanics so I couldn't resist to add some information here.
What kkiepvvessau wants to say, is that the differential does more than just turning the wheels. It also amplifies power just like a gear.

So lets say your engine devellop 200lb of torque at the flywheel. 200lb of torque isn't really alot to move a 3000lb and + car. Thats when the tranny and differential comes into play.

Lets say your first gear got a ratio of 3.0 and your differential a ratio of 3.1
The power your wheels will put on the ground will be: 3.0*3.1*200=1860lb/tq

Now that more likely to move your car. If you swap a lower gear ratio diff, you'll get: 3.0*3.7*200=2220lb/tq. Thats 360lb of torque to the wheels more right there just with that new differential. Not bad huh.

Anyway, I dunno if you all were aware of that, don't want to sound like a smart ass.

No that was a great post. However, it still distributes the power that was transfered from the tranny. A diff does nothing but distribute power to the wheels. It has nothing to do with power transfer. In order to transfer something you must change it to another form. Which the tranny does. The diff just takes that power from the tranny and distributes it to the wheels. I hope I am making sense too.

I think there is a bit of missunderstanding here. Yes you are right, the differential does only one thing: The distribution of the power to the wheels, just like you say. I was talking about the FINAL DRIVE, which is often in the differential housing of a FWD car so I don't know about RWD cars like a supra. But that could be why there is alot of articles that talk about a 3.7 differential instead of saying a 3.7 final drive.

O ok sorry if i misconstrued your demeanor.

No no its my fault :)