I plan on going all n/a with my 86 gtu. My question is, how much power can the tranny handle or would swapping tranny's be better. For example, TII tranny or miata tranny. I appreciate it guys. Gimme all the info you guys have and possibly some links that can help me out as well. Thanks

 

Well, welcome to the forum Chris, lets start:

In 1986 the GTU model did not exist, also, a regular non turbo transmission will handle roughly 230-240 HP, after that good luck, you'll be replacing syncro's and bearings every so often.

The turbo transmission would be a better bet, or even a BEST bet, finding a turbo transmission would be difficult, not to mention parts you'll need to do the swap. As far as i know only the gears from a miata tranny will fit, but i have no further knowledge on that so...

-Markus

"Just my 7 cents"
P.S. With a good port job and full exhaust/intake you could see roughly 200 HP from your n/a rotary... again i'm not sure, cause i havnt gotten there yet either...

 

Well what I'm planning on doing is either going with a Bridge Port having roughly around 270-290 horses, so the turbo 2 tranny would be okay then?

 

270-290 is turbo range. Unless you do a HUGE HUGE HUGE Port job I doubt you'll touch that number.

I would guess around 210-ish.
BUT You will be N/a meaning your lighter.

The GTU didn't exist then. You might have a base(4 lugs)
or GXL(5 lugs)

 

IF you can AFFORD it, have a miata-geared NA tranny built for you

 

The only way you may see that much power would be a Peri port, which is not desirerable to drive at all on the street... It wont idle under 2000 rpms and will get around 10 mpg on the highway... Expect around 250 tops with a peri port

-Markus
"I could be wrong"

 

Well my uncle's friend who's done alot work with mazda speed and racing beat has his 86 running a bridge port pushing around 270+ horses at the wheels easy, and he's the one that's going to be building my motor. But he suggested the same thing as banzaitoyota in just getting the tranny geared with miata gears, so basically pretty much making it custom. If anyone has more feed back please feel free to suggest, I'm open to just about everything.

 

I don't think so, pretty sure there are pp race motors making a lot more than that. Travieso Racing has an rx-3 running a 10.47 in the 1/4, all motor.

 

Umm, I think you missed the turbo under the hood.

I know a guy with a B-port 91 TII with a big turbo pushing 330 RWHP. I doubt an N/A can get up there with him on a B-port.


Also you'll be using an engine with extra porting(5/6 ports)
I heard it's hard to port those unless you switch to TII housings. That's hear say though.I can't back that statement up.