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-   -   RB rear big brake on an FC? (https://www.rx7club.com/race-car-tech-103/rb-rear-big-brake-fc-1017252/)

eage8 11-09-12 12:40 PM

RB rear big brake on an FC?
 
I've been researching my brake options and realized their really isn't much out there for the FC.

and before anyone says "stock brakes are fine" I know... this is very much a research for the future sort of thing.

Anyway...

Does anyone know if the RB rear brake upgrade actually uses the '99 RZ rear brake bracket? or do they actually cast their own bracket?

RB brake upgrade:
http://www.racingbrake.com/RX7-REAR-93-95-p/2107-k.htm

How well do you think a FC-> 99 RZ upgrade + a RB rear floating 2 piece rotors would work?

from what I've heard RZ rotors are near impossible to find in the US now which doesn't really make sense for a track car.

both corksport (NLA) and Super Now make RZ brake upgrades:
Super Now FD Brake Rotor Caliper Bracket Set FC3S

even comes with hubcentric rings...

jgrewe 11-09-12 04:22 PM

First, I'll say it. Stock brakes are fine.

Next, I wonder if you could use the hat that AWR sells for their E Prod legal brake set and just get a different size rotor for it? I'll bet the bolt pattern is a standard size/pattern on the inside of the rotor. You can get custom rotors machined pretty easily, tell Hoerr racing what the bolt pattern is and what dia and thickness you want and they'll have Tilton make a set for you.

The caliper bracket would be an easy item to have made if you are going to use the stock caliper. You could just have a spacer machined to move the caliper and use the stock unit.

eage8 11-09-12 08:31 PM

After I made this post I realized the super now kit uses the FC caliper bracket... so unless the RB kit and the 99RZ brackets are the same, I'm not sure it would work...

I would just have to make my own adapter bracket.

088 11-11-12 11:18 PM

......and that rear brake upgrade will only cost $1100, lol.

On my racecar, I have the stock, base model, solid rear discs. (I have a set of vented rears + calipers from a GXL ready to drop in, but never found a compelling reason to do so.) Brakes performed well during a recent 4-hour enduro in 92+ degree weather. In the past, I've actually had problems with too much rear brake due to an overaggressive choice of brake pad compound. I've never had a problem with rear brake fade or overheating, except after an improper brake job (I switched rear brake compounds without replacing or resurfacing the discs. They glazed, faded, and overheated in a matter of laps).

I realize that doesn't address your post; just offering my $0.02.

eage8 11-12-12 09:24 AM

I'm getting really tired of IT/EP guys telling everyone stock brakes are fine no matter what.

you guys make what, 150whp? My corolla makes about that, and yeah, the stock GTS brakes are fine for the track (which are about the same size as yours).

a 350-400 whp turbo that weighs more than your car could easily need better brakes. RockLosbster was complaining about stock brakes on his stock full weight turbo... I made a set of titanium shims and ducted my front brakes, so I'm going to see how long stock brakes will last, but I'm doing research for future upgrades.

A lot of FD guys have trouble with stock brakes... you know why? because they actually have horsepower... some people don't like replacing rotors multiple times in a weekend.

088 11-12-12 01:18 PM

Mostly I was just curious what the motivation was for upgrading the rears only, assuming you are keeping the stock 4-piston brakes in the front, for the time being. I guess I read that wrong. Thanks for clarifying.

eage8 11-12-12 01:59 PM


Originally Posted by 088 (Post 11284306)
Mostly I was just curious what the motivation was for upgrading the rears only, assuming you are keeping the stock 4-piston brakes in the front, for the time being. I guess I read that wrong. Thanks for clarifying.

No, this would be to use with something like the fastbrakes kit:
1986-1991 Mazda RX7 13" 4 piston performance big brake kit

RockLobster 11-12-12 07:02 PM

Ive had good luck with the corksport kit. Uses stock FD RS/RZ rear rotors. At one time racing brake had a two piece floating upgrade for that size/shape rotor but im not sure it is available any longer. The RB kit you linked as far as i know does not use RS/RZ size rotors. It's something different. It may be close but i would call RB to discuss the differences. I am fairly sure it is NOT an RS/RZ bracket.

I also like the fastbrakes upgrade kit for the front, i have the 6-piston version. It makes the brakes fairly forward bias (almost too much so) but i am able to balance it with compound selection.

There are so many different levels of weight and power on FC racecars, you're right, a single setup will never work for everyone.

The above setup is on my 175WHP PTD rx-7 weighting 2600-2650 with driver.

I got my turbo to the point where the stock stuff works ok for HPDE events but could never last a whole 45 min race. 20 min sessions only. It also goes through pads and rotors a bit too often still for my liking.

RockLobster 11-12-12 07:14 PM

Ahh i see you reference the corksport kit. They would have done a lot better had they not forced you to buy the rotors with the kit so they could mark them up and given the option of just getting the brackets.

jgrewe 11-12-12 08:02 PM

These are the parts I was talking about.

RX-7 - AWR Racing Store

1.Buy the bells/hats for the rear


2. Fill out the custom form here:

Options

3. Figure out how to hold whatever caliper you want to use, why stay with stock if you don't have to, throw some 4 pistons back there.

4. Drive the snot out of the car

Tilton used to offer engineering help with master cylinder sizes and caliper choices on their website. I don't see it on the new design though. You may just go through the 'contact us' link and ask.
4.

eage8 11-12-12 08:04 PM


Originally Posted by RockLobster (Post 11284645)
Ive had good luck with the corksport kit. Uses stock FD RS/RZ rear rotors. At one time racing brake had a two piece floating upgrade for that size/shape rotor but im not sure it is available any longer. The RB kit you linked as far as i know does not use RS/RZ size rotors. It's something different. It may be close but i would call RB to discuss the differences. I am fairly sure it is NOT an RS/RZ bracket.

I also like the fastbrakes upgrade kit for the front, i have the 6-piston version. It makes the brakes fairly forward bias (almost too much so) but i am able to balance it with compound selection.

There are so many different levels of weight and power on FC racecars, you're right, a single setup will never work for everyone.

The above setup is on my 175WHP PTD rx-7 weighting 2600-2650 with driver.

I got my turbo to the point where the stock stuff works ok for HPDE events but could never last a whole 45 min race. 20 min sessions only. It also goes through pads and rotors a bit too often still for my liking.

Thanks, This was helpful.

HPDE sessions around here are 32 minutes... which is another reason I'm worried. I was going to take the FC to a track day a few weeks ago, but didn't have it done in time, so I ended up in my corolla again. I'll find out next year how it goes :p:

The only thing that would worry me about the RZ kit is I've heard rotors are getting harder to obtain... have you had to get new ones yet?

eage8 11-12-12 08:08 PM


Originally Posted by jgrewe (Post 11284692)
These are the parts I was talking about.

RX-7 - AWR Racing Store

1.Buy the bells/hats for the rear


2. Fill out the custom form here:

Options

3. Figure out how to hold whatever caliper you want to use, why stay with stock if you don't have to, throw some 4 pistons back there.

4. Drive the snot out of the car

Tilton used to offer engineering help with master cylinder sizes and caliper choices on their website. I don't see it on the new design though. You may just go through the 'contact us' link and ask.
4.

I've never seen a 4 piston caliper with an e-brake :)

we'll see if RB ever emails me back. I'm not a giant fan of the AWR rotors, you have to modify the hubs, and they're not floating at all *shrug*. You also have to get new rings through AWR or have them custom made yourself... I'd rather use a somewhat widely available ring.

RockLobster 11-12-12 10:40 PM

I ordered a set of RS/RZ rotors to have as spares about a year ago from mazdaspeed. But, with the wear rate i probably wont ever need them. After 3 full years of racing i still had plenty of rear pad left, only reason i changed this year was to try a different, more aggressive compound. I have to believe you will be able to get rear rotors for the RS/RZ from mazda for quite some time yet. Not, cheap but....

I also cryo treat all my stuff though so im sure that helps tremendously with rotor wear.

eage8 11-12-12 10:59 PM


Originally Posted by RockLobster (Post 11284891)
I ordered a set of RS/RZ rotors to have as spares about a year ago from mazdaspeed. But, with the wear rate i probably wont ever need them. After 3 full years of racing i still had plenty of rear pad left, only reason i changed this year was to try a different, more aggressive compound. I have to believe you will be able to get rear rotors for the RS/RZ from mazda for quite some time yet. Not, cheap but....

I also cryo treat all my stuff though so im sure that helps tremendously with rotor wear.

just typed the part number I found into mazdaspeed (F124-26-25XA)...

$192 per rotor :eek:... yipes :)

jgrewe 11-13-12 03:13 PM


Originally Posted by eage8 (Post 11284700)
I've never seen a 4 piston caliper with an e-brake :)


e-brake?!?! I thought we were talking about a race car here, lol. We don't need no stinkin' e-brake!

The AWR kit makes the FC about the best braking car in EP. The rotors they sell with them have to meet the rules, I just thought maybe you could save some dough and use a hat that is already made. Having bigger rotors custom machined isn't that expensive. They start with an assortment of blanks and can turn them into just about whatever you want. I have a set on my IMSA RS RX2 that are stock RX2 diameter but 1" thick.

RockLobster 11-13-12 04:06 PM


Originally Posted by eage8 (Post 11284914)
just typed the part number I found into mazdaspeed (F124-26-25XA)...

$192 per rotor :eek:... yipes :)

Yeah, i didnt pay that. Get yourself 2 sets of TT results per year and save yourself a ton of cash....

eage8 11-13-12 04:12 PM


Originally Posted by RockLobster (Post 11285554)
Yeah, i didnt pay that. Get yourself 2 sets of TT results per year and save yourself a ton of cash....

That was from mazdaspeed, which I'm a member of... they must have gone up in price.

RockLobster 11-13-12 06:29 PM

Maybe i did pay that.....lol....who the heck knows. It all goes into the same blackhole never to be heard from again so....i try not to pay too close attention for fear of crippling depression.

eage8 11-16-12 01:26 PM


Originally Posted by RockLobster (Post 11285708)
Maybe i did pay that.....lol....who the heck knows. It all goes into the same blackhole never to be heard from again so....i try not to pay too close attention for fear of crippling depression.

I think that price increase is actually why corksport stopped selling their rear brake upgrade.


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