What Differential / Final Drive ratios are available?
 

Hi all,

Does anyone know what diff or final drive ratio's are available for the RX-8?

Many thanks.

.ps Did a search and didn't have much luck.

mazdausa.com look for specs there.

What about Aftermarket?

FEED makes an aftermarket set of the final drive. I want to get it, but I'm afraid of how high my rpm will be when cruising on the freeway.

I believe it is a 4.77 ratio.

Some FEED stuff here: http://www.pac-gate.co.jp/feed/rx8.html

68,250 yen = 631.13 USD

Not too pricey, I suppose.

I can't even figure out how to navigate those type of sites. Maybe I need some type of plug in.

I would be interested if something would affect the ratios from 1st thru 4th, but the 6th gear on this car is already too short. I am at around 4000 rpm already when I am cruising on the freeway in 6th.

It's really not that short when you consider it has a 9k rpm redline. I am sure it's capable of cruising at 4500 with no problem. And to reply to any responses regarding fuel mileage, I hate to say it but if you're looking for gas mileage, you bought the wrong car. You could always buy a cheap hatch and drive to and from work if fuel economy is an issue.

I don't feel that way. Why would I want a car that is using up half it's revs at cruising speed ? I would rather have a longer 6th gear. My previous car was at about 1/3 of it's revs at 70-75 mph. You can say something about not caring about fuel economy, but it is part of this car. There are times when I like the handling & acceleration, but there are other times when I want it as an everyday driver & hence a usuable 6th gear. This is not a Lotus Elise we are talking about. It is a practical car, just with a marginal 5th & 6th gear. No reason for it. We are not using those gears (especially 6th) to accelerate.

maybe you aren't . . . . .

Even with the turbo & going 100 mph I wouldn't be using 6th to accelerate, just drop it down a gear or two is how most RX8 drivers accelerate. 6th gear is a fuel saving/cruising gear, as such it should be longer. I would rather have a taller 6th gear & be able to save 1 or 2 mpg & shift down a gear or two for much better acceleration vs. having shorter gearing overall.

Mazda Motorsports offers a 5.12:1 ratio, you don't want to know how much it costs, if you have to ask you can't afford it

Excellent, can you get a hold of these? rough idea on price?? (have to work to some sort of budget! :) ) thanks.

$3600 just for the ring & pinion

Hmmmm.....no response from 4rotor. Think he had a heart attack?

i well instal next wheek the FEED final gear, you must change sam oil seal and other parts for the instal, consult with your woorkshoop
i well post to scoment the change.

I will be very interested in hearing your impressions after the install as I have been very seriously considering the Feed final gear. Will be interesting to hear your impression on what the difference feels like going from 4.4 to 4.7.

Contrarian
 

I would be interested in a numerically lower (taller) rear axle ratio. It would yield better highway gas mileage and make the car more driveable by making 1st gear more useful.

...some of the best 1/4 mile times are done by revving the engine, dumping the clutch, getting wheelspin, and taking off in second gear. The logic of this is you lose more time shifting from 1st to 2nd than you get from the mechanical advantage of the 'stump puller' 1st gear.

the shorter 245/35-18 Kumho V710 tires we're using (24.8" OD) yield an effective 4.66 gear ratio relative to the taller OE 225/45-18 tire and 4.44 actual gear ratio

A 4.7 gear will help, but it's not going to be all that big of an improvement IMO. Highway RPMS will still be reasonable though

What I'd like to do is get a shorter rear with a taller 6th. More acceleration in the lower gears and better freeway cruising. Anyone know of a swap for 6th gear?

~ Matt

Need For Speed, have you installed the FEED final gear? Would be great if you can share with us on how it has improved the car's performance. Thanks.

i did not instal it, i well instal it on friday.
i did not install it befor , because we need to chage sam apex seal and other parts so we have to wait for it.

wen its install i well send pics and let you now the diference.

Mazdaspeed charges $3600 for a ring and pinion? That's insane.

it's probably a custom, low volume, high quality racing part