i've been sitting here in my room thinkin' of whether i should upgrade my brakes to a big brake kit or just replacing with oe size slotted rotors and better pads.

big brakes cost too damn much and i might run into the problem of fitting wheels. oe size slotted rotors and better pads will just leave me with a ugly brake caliper (no...i'm not painting it. it looks cheesy to me).

so my other thought was, finding a front set of FD RX7 brake calipers. they are aluminum, so polishing them would be perfect. they are 4 piston calipers, but fit in the stock wheel (16x8 +50). the only thing i would need is some sort of caliper bracket.

anyone have any thought/opinions on this? does anyone know how much of a difference in size the FD RX7 rotors are compared to the RX8? do you think the stock RX8 master cylinder is adequate?

it would be nice if it works.
my reply wasn't much help since you have thought of most of the problems.
be interesting in seeing what you discover.

RX7 FD 103 4/92 on F vented dia 294 width 22 min thickness 20
R Vented dia 294 width 45 20

RX7 SP Series 6 4/92 on F Vented 314 32 30
R Vented 314 45.5 20

RX8 - Sports Suspension Models 2003 - on F Vented 320 24 22
R Vented 300 18 16

TeamRX8 shakes head and departs thread

correct me if I'm wrong but arn't the 8's brakes better already?

What's is the point of swaping to smaller brakes?

I don't think DAN want smaller brakes, just 4 piston calipers.
I doubt it would be of any benifit. it is unlikly the rx-7 calipers have the same pad area and by the disc sizes above you would need new rotors. then there are potential piston area and master cylinder problems.

if you could use the calipers, you would get aluminium, 4 pots on std rx-8 disc's.

4 piston would equally distribute pressure around the brake pads. the aluminum caliper would also make it lighter and easier to dissipate heat.

Use the brake system from RX7 is not a good idea for RX8
Althought it is a 4 piston set, the performance is not as good as stock one of 8.
I once read the comment on previous (2 or 3 back volume) RX7 megazine (sorry it's japanese megazine)
Brembo, stoptec or alcon system may be a better choice but there are all expansive.

the stock fd 4 piston don't fit the rx8, the rx8 rotor is thicker so the caliper don't go in all the way. i try it out already.

ok...well thanks for the info. that blows my idea right out the window. looks like i gotta either paint the stockers or upgrade to a big brake my wallet kit.

ok...well thanks for the info. that blows my idea right out the window. looks like i gotta either paint the stockers or upgrade to a big brake my wallet kit.
Lol. I like the before and after thing :p Any idea how big you're going to go, or what company? If you do end up going bigger brakes, post up some pictures and a review if possible. This is something I might consider doing down the road. :)

These numbers are from Road&Track ('95 Road test for RX-7, Aug. '04 test for RX-8):

Braking 60-0: 123 ft (RX-7), 110 ft (RX-8)
Braking 80-0: 222 ft (RX-7), 193 ft (RX-8)

So putting the 7's brakes on the 8 would be a very bad move. Given that the 8 already weighs more than the 7, the numbers would be even worse.

The stock brakes are great, and give the 8 a best in class capability. I've seen test articles where tuners "upgraded" the brakes, but the numbers were worse than stock. But if you're after looks and not performance, that's another story.

FYI, the Speedsource RX-8's that run in the Grand Am Cup series use STOCK brake system for their racecars, all they changed are pads and fluids.

ok...well thanks for the info. that blows my idea right out the window. looks like i gotta either paint the stockers or upgrade to a big brake my wallet kit.


Not necessarily. You can get aftermarket calipers in a wide range of sizes. I'm sure you can find some to fit the stock rotor.

for example (http://cncbrakes.com/cncbrakes.com-asp//bac.asp?grp=bac&subgrp=4&series=624-625&subseries=)

I don't know the price, but it's definately cheaper than a rip off big brake kit.

FEED and RE-amemiya have 4 pots for the std rotors.

anyone got some stopping distances for the SP rx-7 it seems to have some substantial rotors

hey guys...this is exactly the kind of info i was looking for. thanks for the heads up. ideas aren't always great :D

I think the rx8 rotor is big enough already, they are 13" dia and 0.9" thick. So i would go for the mazdatrix set up, they are using the brembo cliper with the stock rotors. all you need is a spacer if using stock wheel. The price is cheaper then the other so call big brake kit. "most of the big brake kit using 332 x 32 so the dia is the same only thing change is the thickness and the four piston"

http://www.fd3s.net/magazine_articles/Motor_Trend_article01.10.jpg

That's testing a 1993 R1 model, which has superior suspension and tires to the base model.


Braking 60-0: 123 ft (RX-7), 110 ft (RX-8)
Braking 80-0: 222 ft (RX-7), 193 ft (RX-8)

Sounds like that was on a base model, which doesn't even have Z rated tires. There was no R1 in 1995.

Rx-7 and Rx-8 brake systems are pretty close. If you really want to upgrade your stopping distances then get some sticky tires. More clamping force != better stopping distances necessarily.

The Grand Am racers use the stock braking system of the RX-8 and use racing pads. There is nothing wrong with the stock brakes on the 8. The Speedsource guys use them.

Sounds to me like you are considering brake change just for looks?

The Grand Am racers use the stock braking system of the RX-8 and use racing pads. There is nothing wrong with the stock brakes on the 8. The Speedsource guys use them.


because they have to, they are not allowed to change some parts per the rules, otherwise they'd do it for nothing more than the weight savings, the OE brakes are heavy.

The Grand Am (http://www.rx8club.com/#) racers (http://www.rx8club.com/#) use the stock braking system (http://www.rx8club.com/#) of the RX-8 (http://www.rx8club.com/#) and use racing (http://www.rx8club.com/#) pads. There is nothing wrong with the stock brakes (http://www.rx8club.com/#) on the 8. The Speedsource guys use them.Almost, except it appears they'd rather use these guy's rotors... Full text here: http://forums.racingbrake.com/viewtopic.php?t=42
(for the RX-8) We believe the most needed brake (http://www.rx8club.com/#) upgrades is a better rotor and pad while caliper upgrade is not as essential in terms of the extra cost vs. the improvement you can gain w/o even regard to the extra cost required for larger rims (http://www.rx8club.com/#) and tires (http://www.rx8club.com/#) in most cases (luckily RX8 has 18” rim (http://www.rx8club.com/#)). In fact we are offering our same two-piece rotors to Sylvain Tremblay – A well know Mazda (http://www.rx8club.com/#) racer (http://www.rx8club.com/#) who prefers to race with stock caliper. (His review on our rotor will be posted) http://speedsourceinc.com/index.cfm?template=ssabout (http://speedsourceinc.com/index.cfm?template=ssabout)

because they have to, they are not allowed to change some parts per the rules, otherwise they'd do it for nothing more than the weight savings, the OE brakes are heavy.


Thanks for the clarity. We were talking with Speedsource at Barber Motorsports Park and they were very happy with the stock brakes. Hell, I'm happy with the stock brakes. I put HP+ pads on and now when I stand on the brakes, it emties out my tear ducts. :)

trust me, he'd rather lose the weight & inertia ....

If you must change the caliper, these seem to be reasonably priced:

http://mazdatrix.com/8brakes2.htm