I'm looking for a tranny for road racing.
a friend told me that the rx8 comes with real close ratio gears.

anyone knows what are the gear ratios for the 6 speed RX8?

also will it take the abuse of road racing, I have a PP eng. in the 300's HP.
with 5.12 rear end.

 

some of the rx8 owners kill their trannies under stock power levels.

try a miata box... they're dirt cheap.

 

http://www.google.com/search?hl=en&q...mission+ratios

 

Transmission Ratios
1st 3.760
2nd 2.269
3rd 1.645
4th 1.187
5th 1.000
6th 0.843
Reverse 3.564
Final drive 4.444


With 300hp you'd probably want an FD transmission right? Or something beefy like a tremec?

I heard that the RX8 6spd is pretty much the same transmission as the Miata 6spd. True?

 

thats true.

 

t56

 

There a miata 6 speed on ebay. but it doesn't look like it will bolt up.
will I need to change the bell housing?
will I need to change flywheel, cluch + plate?
I dont see a starter.
http://cgi.ebay.com/ebaymotors/ws/eB...MEWA%3AIT&rd=1

 

fc, fd, or miata tranny--just because they're cheap.

what car is it going in? the fc trannies are just as strong as the fd's...for half the price. so maybe pick whichever one will fit the easiest.

 

i've been thinking the same for my FC. is there a right up or diy available for a rx8 tranny to FC or FD?

Diddy

 

it'll bolt to the motor...the rest is easy.

 

Racing ain't cheap.
With a 300hp PP, you're going to blow up almost any non-turbo transmission out there, unless you really baby the shifts and the start?


-Ted

 

if your looking for close ratios I might suggst the mazdaspeed miata they have close ratios and the trannys are somewhat strong b/c they take the power of a t28 all day

 

its a 6 speed too!

 

It's going into an FC.
I have a TII in it now but I want the xtra gear a 6 speed will provide. I will only use 2-5 in racing.
I've heard the prob in the RX8 is from 1-2 gear, which I'm not going to use.
and I also heard the RX8 tranny comes with 3 syncros just like the FD and is just as strong.

 

You'll blow up the 6-speed.
I put money on it.
The gears are thinner just to add the extra gear in there.
It's not stronger than a turbo trans.
Good luck.


-Ted

 

the mazdaspeed miata tranny is the same thing as the rx8 tranny except for the bell housing.

 

you might have better luck with a 5-speed miata box and a different ring and pinion.

 

Ever drive one?

They are not close ratio in the racing sense. They are mildly close 1-4 and then 5th and 6th have a nearly useless spread. A more common T10 transmission has almost the same 1-4 ratios, and shift quality... A T10 with a half decent shifter shifts so smoothly, cleanly, and quickly it is almost telepathic, whereas most T56s need two hands and maybe a foot to shift. I've driven trucks that shifted nicer.

 

I road race a PP motor car. The ratios in ANY production street transmission are too wide for a peripheral port road racing engine to use. Yes, you can try and be cheap and use a transmission out of a production car, but you will get beat by someone who has a real race transmission with close road racing ratios (Happened to me until I got a road race tranmsssion.) A 15% drop in rpms with each redline shift is common for road racing rotaries, that works really well. You may live with a 20% rpm drop during a 1-2 shift or a 2-3 shift, but in the 3-4 shift and especially the 4-5 shift, you do not want more than 15% rpm drop (if you shift at 9000 rpm, then the next gear drops to 7600 rpm.) I have been road racing a PP motor since 1997, and I have not found a winning alternative to a real racing transmission with very close ratios. The winning cars I know use first gear 2.00 or less, and a 1:1 fifth gear ratio - no power robbing extra pair of friction making overdrive gears. Saenz, Jerico, and G-Force sell winning race transmissions. Saenz is from South America, and they should be able to serve you in the Dominican Republic.

SAENZ Racing Transmissions
10915 SW 156th Terrace
Miami, Florida 33157
305-252-1207 phone / fax
(Racing transmissions)
dadwithgas@hotmail.com