4.8 final drive
 

Autofactory and a few other brands have a 4.875 final drive. I think its a Toyota part and is about 19% reduction over the stock 4.1 ratio.

Has anyone fitted one? How is it?

I'm planning to keep my car NA and I think this will really make the car come alive. I think subjectively it will make the car feel much quicker. Objectively, it may not mean a faster lap time, but I don't really care about that..

I've got 5.1 and love it.

Got any videos for this? The only racing footage I've seen on youtube is from autofactory japan with their 5.1 racer.

Awesome.

Was it the autofactory one? Who fitted it for you? Any noise?

I am very interested too in a review...DD, track, performance, highway, anything :)

Weir Performance has am inexpensive 4.88 too fyi ...they also have a 5.29 for the brave ;)

5.1 wow I have the 4.55 and also love it exept on the highway revs are too high for cruising

whats youre crusing?

4.88 would do amazing things for an automatic.

The supra kit? goes all the way up to 5.71. IDK for daily 4.88 seems like a bit much, but it would keep me from speeding! and be good for AX

Can someone elaborate on this please?

The auto has taller gears in the tranny than the manual while both have a 4.1 final drive. So a more aggressive final drive would bring the auto more in line with the manual.

How costly is something like this start to finish having a shop do everything?

The automatic is pretty fun to begin with, but the internal gearing (in the transmission) puts it at a huge disadvantage to a manual because both have the same 4.10 rear gears from the factory. There's a reason the manual is a full second quicker and it isn't just the weight. A change to a ratio like 4.88 would give it much more favorable overall gearing on line with the manual. Ever notice that automatics in muscle cars have higher (numerically smaller) final drive ratios than manuals? That's because of the torque converter's multiplication effect. You quite literally don't want too much of a good thing. I'm making a quick guesstimate that 4.88 would be enough to wake the automatic up nicely without going overboard. Someone with easy access to gear ratios of the transmissions (they are on the forum somewhere) could be more precise.

Edit: Damnit, while I was typing that mess, the short answer got posted.

Lots of discussion here: http://www.ft86club.com/forums and here: http://www.ft86club.com/forums/showt...ad.php?t=27647

If I recall correctly from the above (and at least one other) thread labor was close to $1k. Obviously cheaper if you can do the installation yourself, but it is something you have to get right the first time and takes a lot of experience.

Parts can be fairly inexpensive if from a donor or pricey if you buy from Cusco, MFactory, etc. The second thread includes part numbers and more detailed pricing for at least a partial DIY project.