I am toying with the idea of swapping a gs430 3.26 rear into my 93 sc400....

I am under the belief that they are 100% swappable...


Driveability wise has anyone tried this and can comment on it? INcrease in fuel economy?

If anyone cares to comment please do.

Thanks!

-Brad

 

I put the Supra Diff in 3.76 ratio...

I think the 3.26 might be a little too low.

My car now loves to go 80 on the freeway. Thats at about 2800rpm. Thats when the 4 liter wakes up.

But unfortunately at 65 I might only be turning like 1500 revs per min... makes it seem sluggish and need to downshift from OD to 3rd gear to get decent acceleration on the freeway.

 

You will likely see an increase in fuel economy from the swap. The 3.26 rear end would present you with a 17% decrease in gearing.

The car would rev less and consume less fuel so long as you were maintaining a constant speed. When trying to accelerate, there would actually be more load on the engine and transmission (less load on the axles). That being said, the car would consume less fuel so long as your driving habits remained the same.

Performance would definitely suffer. 17% less torque to the road will make the car even more of a slug off the line than it is in stock form. First gear would drop from 11:1 to 9.2:1. This would be good for performance if you made 600ft*lb of torque off idle. Sadly, what used to feel like a motor with 260ft*lb of torque will now feel like a motor with ~216ft*lb of torque. This will offer the perception of the car being heavier than it is when accelerating in a straight line.

Moral of the story: you will gain economy and you will lose performance. The power band will take some getting used to. Your highway economy should increase most significantly. If you often just cruise with the car and have a feathery light foot, your pocket book will thank you. Even then, you will need to be weighing the significance that 2-3mpg will have when the 3.26 rear ends go for ~$300 (plus install if you are not intending to do the job yourself).

If you are still interested in acquiring a 3.26 differential, I have one in my garage that I am willing to part with for a reasonable price. Feel free to drop me a PM.

 

thats blizzy for you

 

I will running the TH400 and need a lower gear. PM sent.