TeamRx8,

Have you competed in that class yet? How does the 8 fair?

 

We have very few 8's going stu in my area. Not to say that with the right setup and driver they couldn't compete. The STI's seem to pretty dominant in FL.

Edit- I don't guess that it has much to do with 2 piece brake rotors

 

first time is detailed here, just class-legal tires and wheels on a Stock class RX-8, I think those of us with RX-8 autocross experience believe it should be very competitive on a Solo2 type national course

https://www.rx8club.com/rx-8-racing-25/phat-76896/

RacingBrakes clarified that they "estimate" a 2-pc rear rotor will shave off approx. 9.6 lb. per rotor, so quite a bit more than the front rotors. Probably less weight savings than the front on a replacement rear caliper if they end up pursuing that too.

Note that despite being lighter than OE their 2-pc OE replacement and 13" BBK rotor has equal or better heat sink mass capability and in theory better air cooling capability than the OE discs. The main rotor weight savings is in the aluminum hat. The caliper heat sink mass has no real effect on braking capability so that's just less weight for the suspension to control and the engine to work against. The exception is that if it's too lightweight it will flex too much which can lead to less feel under braking. However, their caliper weight and design seems inline with the usual caliper manufacturers.

IMO, at the pre-sale price the cost is extremely attractive for what they are providing. I'm sure a kit such as Stoptech costs more for a reason, but be realistic; how many RX-8 owners are going to be running 10/10ths competition laps on the fastest road courses in America? Not too many ...

 

you have different (width or ?) wheels front & rear, all with the 275/40-17 MX's on them?

 

different widths for clearance (they didn't have unlimited offset choices). I'm running 8" in front 9" in rear with 275s all around (don't start with me on tire flex/turn-in and all the other associated cons there is still more rubber and more grip and with the right pressure )

On another note... Are you going to be running Azenis, Kumho, or other?

 

The guy who placed 2nd at the Atlanta Div. this year in STU was running that size on Stock Rims with coilovers down about 3/4''. I talked to him about it and he said no problem. I didn't see any signs of wear, but I didn't really check the insides of the tire. I remember because I had just purchased the 245s (still use them to/from events) and was dissapointed that I hadn't checked around a little better before buying.

(edit: just as I was typing the answer appeared. Issue is 9" rims on the front. Duh.)

 

read the other thread...

...nice RPFs BTW

 

well the MX's have very soft sidewalls, don't try that with the Yoko Advans

 

Will those calipers fit the stock sized rotors? Seems kind of silly going with a bigger rotor, to me.

 

to bad they only come in red..i would like black calipers lol

 

Does anyone know what kind of research racing brake puts into the caliper valving in their big brake kits to ensure proper operation with the rest of the rx8's brake system?

The reason I ask is all I can find on their site is alot of info on their rotors.

 

I had the same thought about their focus on rotors to the exclusion of all else on their web site. After reading through the Stoptech site and realizing the problems possible if caliper/piston design is not considered for each vehicle's specific electronic's and braking profile, I am wondering too.

Although the big brake kit is a nice price, are you simply getting what you pay for, or is it a good deal? Inqiring minds would like answers for these questions. I've left a question to this effect on their forum, lets hope they have suitable answers.

 

BTW, here's the linkie to that question I put to them http://forums.racingbrake.com/viewtopic.php?t=42

I note today they answered the questions extensively today (Sunday!!) . They certainly seem to be trying to accomodate us with options for our car which is very helpful. And what I get bottom line from their answer is that they seem to be recommending upgrading the rotor and not the caliper. The wording is a bit difficult to follow in places but the part here,

"You will probably agree that the need and importance of aluminum caliper upgrade is somewhat over-emphasized in the performance industry. If you look closely for the size of rotor they offer; basically only three sizes: 355x32, 332x32 and 328x28 regardless of vehicle weight and speed while the remaining variation are caliper piston number and size, brake system design and bias etc. which is usually modified and dealt on the professional level while the tracks and those racers are well equipped to deal with the situation resulting from any possible malfunctions of the brake system and we believe it’s somewhat beyond our targeted customers and enthusiasts here."

and they continue,

"Our advice to customers are buy just just what you need and don't waste money and buy something you don't need such as BBK unless you really need it. So just remember for RX8 we have the same offer; one-piece, two-piece stock replacement and 13" BBK. We suggest customer to upgrade to our two-piece stock replacement first and later on if you still wants to upgrade to our 4 piston caliper kit he can just add the caliper and adaptor but still can use the same rotors (stock size is 322x24 and BBK is 332 the different is not much)"

and something I didn't know,

"In fact we are offering our same two-piece rotors to Sylvain Tremblay – A well know Mazda racer who prefers to race with stock caliper."

I still didn't see (someone correct me if I'm wrong), that they have designed their caliper to OEM spec to preserve our brake system electronic aids, unless this says it,

"Our kits are carefully engineered and built within OE design parameters which is safe and sound than any competitions."

I guess saving money getting only the rotors and getting better performance isn't so hard if we do what they suggest

 

are you planning on running Lemans or something?

 

I'll take that as a friendly ... but if I'm going to spend $$ and time screwing around changing an already good setup I don't want simply flashy 4show-junk. As a technically oriented tuner I want safety 1st, along w/quality and performance. I see nothing unusual about asking someone to clarify what they sell w/facts.

 

I guess that means the caliper is compatible with stock sized rotors. That'll make buying the whole thing in pieces an option.

I'm not after brake performance upgrades as much as unsprung (or sprung) weight reduction. Any weight reduction in this car is difficult. 50lbs or so off the corners would be nice. If the superchargers ever make it to market, the braking upgrade will be a nice plus.

 

So true. Trying to get anything out is and 50 lbs is PFG I'd agree. I think it would be a hellofa lot easier (and no more expensive) if we could finally just throw some HP (read SC) at the car rather than piecemealing it off this way .

And then there's dieting LOL!

 

you can do anything you want on the street if you have unlimited funds, but if you want to compete in a particular class you have specific allowances only and if it's a hobby and you don't have unlimited funds then you have to look at getting the most bang for the buck.

Of course if you're a technically oriented tuner you won't have any issue dialing it with some mods if it does turn out to have an imbalance

I assume you'll also be using Koni 2822 4-way adjustable IRL shocks with Ti springs rather than some cheap ol' Koni SA or Tein street shocks

 

What's with the hostility? These 2 piece rotors are the cheapest you can get. Which is not much of an accomplishment really, considering the price of the few others. Half the point is to reduce weight. Cheaper, one piece rotors won't cut it in that respect. Weight reduction from the calipers is nice too. But if you're going to go with the calipers, it seems a good idea to make sure they're fully compatible. I guess I don't get why this upsets you so.

 

there's no more hostility in the answer than in the question we're just talking, I have my own way of making my point, lighten up ...

I guess I'm confused since I'm going to get a set, I'm not upset about anything I can only guess that you completely misinterpreted my response

 

2-piece rear rotor now coming

http://forums.racingbrake.com/viewtopic.php?t=45

 

The rears in our car don't use an integrated drum brake in the rear...therefore the hats have nothing to do with the parking brake......

Subi's use that type and need a different type of rear rotor

I'm sure ours will be aluminum

 

d'oh, my bad, I hadn't really researched it, apparently I misunderstood the parking brake issue from previous thread conversations about it, post edited including the proper thread link

 

No prob...let me know if they e-mail you anything. I'm on the list for rears too......

 

yeah, looking good