upgrading final drive on AT...
 

Hi all, I've recently been searching for a way to add a little better acceleration without HUGE amounts of money. It's still super fun to drive ~ but just looking to get a little bit more out of it.

From what I've been reading, a lot of people have been saying good things about upgrading to a lower final drive.

I've been reading into this, but I haven't found any information about what else I'd need to do when upgrading this? Or is it simply slap on and go...

Please help a noobie out :thanks:

Well, Kiibiiin , the first thing I would do, is leave the final drive in your car alone.

Just what/who do you think you're going to out accelerate ...... ??

See ....... I just saved you a ton of money ....... ;)


humfrz

I'm not trying to out accelerate anyone or anything, just trying to make my personal experience with the car more fun :).

what type of budget do you have? Lighter wheels and tires are an easy way to get a bit more out of the car. Check out this thread. Good idea what it will really do.

More fun would be to take car to the track :)
Meanwhile, IIRC FD isn't exactly HUGE sum of money, and can be made less with some compatible parts (recall mentioned some lexus/supra FDs). But i guess one should double check for all parts needed if performing change. As that is not mod i'm currently considering, have no threads bookmarked around, but just use search. Best results probably would be using google, by adding site keyword, like "site:ft86club.com what you want to search". Find ten or so related threads, read them through .. most probably all your possible questions have been asked and answered already. FDs are not that expensive compared to several other mods. For example more then FD i'd prefer having close ratio gearset, but there parts alone cost 2K, and then one needs to factor in work.

I have an FR-S with an AT as well. In the very near future, I plan to get a set of ring and pinion gears from Weir Performance. I'm going to go a touch extreme, and get 5.29's but he has a number of ratios available and seem like a great shop to work with from my initial conversation with them.

HTH,
Christine

I've aactually lready made the wheel and tire upgrades! This was the next step for me performance wise. and I've seen that thread! Helped influence me to make the decision to get this upgrade.

I do plan on it within the next couple of months once work starts to die down and I can make necessary preparations.:thumbup:

And that google search feature worked! Was able to find this thread because of it, thanks so much! Not sure why it didnt pop up from the past couple of days I've been doing my research...

http://www.ft86club.com/forums/showthread.php?p=1275527

I have a 4.55 final drive in my manual and we recently installed the same unit in my friends automatic.

We used Toyota Part 41201-19557, it's a 4.556 Final Drive Kit and ours contained all the parts required. There are other posts on here that can detail everything you need if you are planning on doing it yourself.

For both, his car and mine, we took the differential out of the car then took the whole diff housing and the final drive kit to a gearbox shop to be installed. This made it a bit of DIY mixed in with some professional help for to get things right. The cost wasn't too bad this way either. If you can't DIY you will have to take your whole car into a shop to get the work done.

The final drive change in both cars has livened them up quite a bit. I would say with an automatic you could easily go for a 4.6 or 4.8 final drive without being too high as the gears in the auto are different to a manual car.

In my opinion, it definitely adds more smiles when driving the car.

I wouldn't say it's an "upgrade", it's just different. Depends what tracks and corner speeds you need. I wouldn't go past 4.55, the 6AT TCU uses more data than just engine speed to change gear, so it holds gears longer than neccessary on 4.88.

If by slap in and go you're referring to do it all yourself, then no. You're likely going to need to take it to a transmission shop for them to install the gear.

Just do what I did, be stupid and spend a ridiculous amount of money and change the final drive to a 3.73 and quadruple the power output. It will definitely make the car more fun.....

Would that matter if I'm using paddles?

I put a Cusco 4.556 in my AT. It definitely helps the car accelerate more quickly, both in automatic and manual mode. It is also quicker if your are NA or FI.

There's a couple of things you might want to watch out for though.

1) I found that in automatic mode when accelerating hard that sometimes the car would hit the rev limiter before it made the up shift.
2) I believe that the TCM has a lookup table of speed/gear/rpm that it uses to determine if you can safely downshift the car. With a different final drive it might be possible to over-rev the motor on an aggressive down shift, although I haven't had it happen with 4.556s.

Hope this helps.

I wouldn't change the final drive of an AT without getting AT reprogrammed for the new FD.