That car uses a 3rd gen tranny with GURU dogbox internals.

Think of it this way, they stuck an extra gear in a smaller package. That means the gears/internals are physically smaller. Smaller gears are not the best thing for high torque/hp cars.

I can't think of one reason to fit one of those tranny's in a 1-3 gen RX.
If you really want a 6th gear, there are much better alternatives.

 

What about using an FB tranny for closer gear ratios?

 

lol..... i read that info in "import racer" a while back.... so, i assumed they knew what they were talking about....... everyone is wrong from time to time.... sorry for the mis-info!!!

 

Like what? People here are asking about having a 6 speed transmission that works, the rx8 one will work. Its obviously not the best choice as discussed above, so let us know whats an alternative! Can't stand when people just cut off ideas.. let us know what your talking about please.

thx

 

RX-8 Gear Ratios: 3.76:1, 2.27:1, 1.65:1, 1.19:1, 1.00:1, 0.84:1
Final drive 4.44:1

Type-M Gear Ratios: 3.475:1, 2.002:1, 1.366:1, 1.000:1, .0711:1
Type-R Gear Ratios: 3.483:1, 2.015:1, 1.391:1, 1.000:1, 0.762:1

I'm no transmission expert, but I don't know that you'd acheive that much of an advantage. It looks to me like you might get better from a stop acceleration because of the taller first gear, but other than each gear seems to have a similar difference inbetween them. Often the biggest claimed advantage of a 6-speed is the improved fuel economy. I think your fuel economy would be noticably worse on the highway and perhaps the similar elsewhere.

 

Late model Supras and F-bodies can be made to work or just about any other 6-speed for that matter.
Kennedy Engineering can adopt just about any tranny to any engine, all you need is money.
Contact them for specifics.

 

Well I have a 04 RX-8 AT and I am having trany problems allready as well.
I personal would be interested in puting the 6sped in a 7 thow the RX-8trany 6sp is the same 6sp tranny that is in the miata. Acording to mazda the AT is a stronger tranny then the 6sp and quit a bit acualy. Thow the load carectoristics stock on the AT are horrble and defanitly need reprogrammed.

 

English?

Anyways, the Auto tranny rx8's also have a worse engine and lower redline, so of course they'll last longer.

 

Heres a good idea. Instead of us trying to guess what the out come will be. Why not just try it? If flamin roids wants to give it a try. Then let him do it.

We can only gain information from experience.

For some reason I always see threads like this, pple saying well what if this, what if that. It means nothing.

Will someone please try this tranny crap, an post pics and info an let us know how it is.

IMO, the rx8 would be good for any Na rotary, just for the fact of the smooth tq curve.

Good luck.

 

**** it all, get an allison and never have another trans problem again. as long as you dont idle in gear.

 

mrx rotary said something bout a fb tranny well bout 2yrs ago i had to replace my clutch and come to find out that my 2nd,3rd gears were going out (past owner) the mechanic said that he had rolled his fb 6 months before and it was just setting there.we got to talking and i bought it for $75 and it had just been rebuilt not to long before he rolled it but anyway i dont know the ratios of the gears or anything but i do know that going through the gear box the fb is quicker in my eyes this was bolted up to a n/a if the rx-8 for some reason doesnt workout try that just my 2cents

 

Well the cool factor is definitly on the RX8 tranny's side. A 6 speed FC will be a rare one. BUt I do like the gear ratio on the TII trans and I'm not to thrilled about having to rig a speedo sensor. I'm sorta reconsidering it but the experience will definitly be useful. Is there no one who has attempted this?

 

Another problem will be that(i think) it is a pull type clutch instead of a push. If this is true, because it is in the 3rd gen rx7, youre gonna need to use the rx8 flywheel, clutch, etc.


sounds to be more trouble than its worth. Bottom line is mazda trannys SUCK ***!!!!


Im on my third tII tranny. My first was s4, my second was s5, my third is s5.


S5 tranny tII is stronger. The only problem im having is synchros blowing, then taking out the tranny after awhile, losing 5 and reverse.


One more thing. Mazda could have very well changed the bell housing, seeing as how its not a regular 13b. dont forget, the renesis uses side exhaust ports. They could have possibly changed the casting completely, as well as changing how the bell housing bolts up.



Look into all of this before making a rash decision.

 

I thought that the whole reason behind the exclusive use of the lower powered renesis engine in the automatic was because Mazda didn't have a torque converter that could handle the torque or revs. The torque/power argument doens't make a lot of sense to me because other Mazda RWD cars like the FD and Cosmo have more torque.

The Type-R trannys seem to be rather stout. gotrotors, I think you've just had some lousy luck. My car at 152k miles and is on it's original tranny.

 

Yeah, the ratios in the FB are shorter, depending on the year. I was thinking about doing this myself since I could probably get an '80 or '81 tranny for free or cheap.

'80 & '81 gear ratios (look at iluvmyrx7.com or something for other years):
1st: 3.674
2nd: 2.217
3rd: 1.432
4th: 1.000
5th: .825

FC N/A gear ratios:
1st: 3.475
2nd: 2.002
3rd: 1.366
4th: 1.000
5th: 0.697

 

flamin roids-

You said you measured both trannys right? So that would mean you saw the rx8 tranny. If you can see it again check out the bolt pattern. Also for you speedo, just buy an electirc autometer speedo gauge. Who needs speed anyways?

This can be done, it just takes time an money. How much of each I dont know. Find out some more info about the tranny an get back to us.(bolt pattern, shifter location, gauge wiring, etc.)

Good luck

 

Couple of things.

Bolt pattern, get a rear iron and go hold it up next to the RX8 tranny and SEE if the bolt holes line up.

Get an E-shaft and SEE if the splines line up

Get a GPS and mount it to your dash for a Speedo. problem solved except mileage ticker.

 

g

 

I'll politely disagree. I'm running an S4 T-II gearbox behind a 20B, putting out 478 lb/ft of torque. After 50,000 miles, it's still running strong. Truth-in-advertising: I don't do drag racing, which helps with longevity.

Switching to Redline gearlube made the synchros a lot happier. YMMV

 

Guys I have an RX-8 and as much as I love it, the transmission sucks. It is the same transmision out of the Miata. We are having alot of trouble keeping them together when we have applications with more power, ie the SpeedSource team in the Pan-Am series said that every 6 races they have to replace the tranny. The Tranny will not take the power of the 13B-REWs and 20Bs that have been dropped in, they all use the thrid gen tranny. Now that we are finally getting turbo applications even more people are having problems from jsut daily driving. On my RX-8 I have SR pullies, SR high-flow CAT, K&N intake, Borla Exhaust, and ZEX wet Nitrous, so far I have not had alot of problems out of it but soon I will be adding the Greddy Turbo and I am a little worried about pushing it too hard on the track, that's why I got my FC. IF you plan on building this motor I would not suggest putting an RX-8 tranny in it, now if it is just for show a six speed RX-8 Tranny dramaticly increases the cool factor.

 

it sounds like the best thing to do is to stick with the tII's or the 3rd gen. but the mazdaspeed rx8 coming out sometime next yr will be forced inducted (supercharger i believe) and hopefully mazda will put in a beefier tranny. IF that happens, then go for it.

 

Six speed is what my gslse need bad! The car running 4k on the highway is bad.

 

Any one know the transmission code for an Rx8 tranny.

 

Compare the top gear ratios between the RX-8, what I posted and what MRX_rotary posted with the FB. (although I'm not sure why our FC numbers conflict - I took mine from Mazda's FC book by Yamaguchi) If you want to lower your highway revs the top gear ratio in the FC transmissions would appear to be the better choice.

 

I got mine from this thread:
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/specifications-what-did-2nd-generation-rx-7-come-w-options-standard-features-249616/

Apparently, the N/A's 5th gear ratios started changing from .711 to .697 in the 1987.5 and 1988 models and all N/A S5s have a .697 5th gear. I learn something new everyday.