I have an automatic and want to increase my rpm's across all speed ranges. I do not drag race. I run road courses (i.e., Mid-Ohio) and need an additional 1000 rpm at all speeds to compete with manual trannys. I have two choices, one increase my final drive ratio from 3.91 to 4.3. This will increase my rpm's by 500. Or I can install a "looser" torque converter, which can increase my stall speed by 300 to 1000 rpm. Torque converter upgrades are normally used on cars that drag race. Anyone have any comments on which option I should use? Also, should I dyno the car prior to selection?

 

I've heard good things from the AT owners who have done the diff ratio swap. I havn't heard of many AT owners swap the converters out ( one did from level 10 but that's another story, stay away from level 10). By the time the converters need swapping it's usually due to the power increases being too much for the stock torque converter, and most people bail on the AT and swap in a MT.

I plan on moving to a 4.3 when I get my bushings from Jim since I'm going to have to take the diff off anyway.

If you need even more rpm's you can get 4.7 ratios.
www.rx7.com I know has them, others probably do also.

Matt

 

I just want a manual..... not enough money to spend though....

 

I am probably going to swap to a 5-speed. No matter what you do to the auto tranny, it will still be a minivan tranny that Mazda added as an afterthought. After months of pestering the local mazda tuner to install some sort of ecu, he finally said, "look I could take your money, but there is no way that the automatic transmission will handle that much power." Too bad I had already ordered a new torque converter and pts upgrade kit. I don't know, I may still try those out, what else can I do? I also notice how hot the trans tunnel gets. Passengers comment on it. Does that happen with the 5 speed? Can anyone whose done the swap add some comments?

 

im wondering how much it would cost to convert, and who would do it, i might like to work on my car but i dotn think i could handle that....

 

I have had the same question, but finally decided to wait until the whole thing exploded before I converted to a manual transmission. I think I read on the forum at one time that one of the members was going to do a step-by-step conversion with photos, but then again, I was probably hallucinating. In any case, I would save my money for a conversion.

Also, I was wondering where you have your car repaired. I live about 50 minutes down I-71 in La Grange, KY. I am looking for a good rotary shop within a few hours drive.

Dustin

 

From everything I've looked at regarding converting an AT to MT, the easiest way by far seems to be swapping out the rear engine housing while doing a engine rebuild. If you do it that way, everything is in the right place for the MT. It's probably not the cheapest way of doing it but if you have an AT and the engine dies, and you've ever thought of swapping trannies thats the time.

Matt

 

On another thread here I read about swapping in a t-56. It's a 6 speed and it's pretty cheap. I think there is a place that makes an adapter plate for the bell housing.

 

Dustin, we (The Cincy RX7 Club) take our cars to AIM in Indy (www.aimindy.com). BTW you may wish to join our Club, a few guys come up from KY. We have 42 members. Go to http://ubb.cincyrx7.com and register and view our board.
Lou

 

Lou,

DO THE CONVERSION!