Shanty

I've got an opportunity to get a 400 diff pretty cheap. And I've got a place that will install it cheap. Is this a worthwhile change? It seems to me that I'd get better mileage and better top speed (excellent!) but I might lose torque overall at the wheels based on the longer gearing. Am I correct in this assumption? Any 300 owners done this?

romycha1

iTrader: (3)

This is interesting... while I don't know much (or really anything about gearing), the idea sounds feasible

Shanty

The guy who has the diff said it's something he's seen on a couple other 300's. I'd bet that if you had the horsepower and torque from the engine it would be an awesome way to squeeze out extra speed and efficiency. I'd be worried about actually losing performance due to longer gearing. But really I have no idea which is why I'm asking.

TheRonTom3

iTrader: (5)

the SC400 diff is either a 3.26 or a 3.76 so it wold be an improvement over your 4.08 on gas mileage and top end but you'd lose some of your nice low end pep

trancuongv

iTrader: (3)

The SC400 was 3.92 from 92-97 and 3.27 on the VVT-i models with the five speed auto trans.

The SC300 was 4.27 for the auto trans all years.

The SC300 M/T was 4.08 for all years.

SC300 and SC400 pumpkins are identical.


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Note: Club na-t info is wrong in the case of the 97 SC400. The 97 has the four speed trans and a 3.92 ratio. The drivetrain of the 97 SC400 is identical to the 96.

This is from Blizzy's post on another thread.

v8soarer91

sc400 3.9
sc300 4.11 auto and manual

sc300 to sc400 diff is around 300 - 400rpm lower on the highway

supra na 4.11 torsen lsd
supra tt auto 3.9 torsen lsd

aristo 3.4?? from memory

romycha1

iTrader: (3)

Hmmm very interesting. If I come across a 400 diff I might have to pick it up...