I believe the Mandeville kit split the stock caliper, and added a spacer between the caliper halves to allow for a thicker rotor. A thicker, stock diameter rotor with RB's vane design, especially if used in combination with a good ducting system, may add sufficient cooling to be a cost effective braking solution. It would allow use of stock size pads, and doesn't mess with the front/rear bias. It might not be as good as a larger diameter rotor, but it might be a lot cheaper than a BBK, and for my power levels on the track I run (Thunderhill) it would probably keep my happy for quite some time.

the really neat thing here is that we have a manufacturerer that is LISTENING to what are needs are.

what is it that the FD community needs???

do we run 16 inch wheels?

i run 18s. there are lots and lots of 17s.

if the demand was there to do a fit under the 16 inch wheel w either the stock caliper w and extension or a wider rotor where would the demand be?

until RB, it was here's what the vendors offer. buy it or not.

we currently have an opportunity to have what WE want.

so what is it?

perhaps a poll??

howard coleman

My understanding is that the Mandeville will throw off the brake bias.

Also, the price seems the same as some of Racing Brakes other OE brake caliper kits WITH larger two-piece rotors.

:-) neil

I was thinking along the same lines. Lets get Warren at RacingBrake some market research so he can build accordingly. Maybe something like:

Option 0:
USDM 93-95 oversized rotor using relocated RB caliper kit
Option 1:
USDM 93-95 replacement rotors: 1 piece, Stock sized
Option 2:
USDM 93-95 replacement rotors: 2 piece, Stock sized
Option 3:
RS/RZ replacement rotors Front and Rear: 1 piece
Option 4:
RS/RZ replacement rotors Front and Rear: 2 piece
Option 5:
RS/RZ replacement rotors Rear ONLY: 1 piece
Option 6:
RS/RZ replacement rotors Rear ONLY: 2 piece
Option 7:
RB larger front caliper (to be run with what sized rotor?)


I'm currently running the 99 spec RS/RZ setup so I would be most interested in a set of rotors for that application. Cost would determine whether or not I care if its one piece or two piece.

Better add 13.0" front rotors to that, because there are a lot of people with aftermarket 13.0" front brake kits. I will certainly never buy another set of rotors from Precision Brakes after the experience I had with them.

For the Stoptech and AP brakes out there?

I believe Option 1 and 2 are already being offerred by RB:

http://www.racingbrake.com/MAZDA_RX7_s/233.htm
http://www.racingbrake.com/RX7_s/3213.htm

To clarify Option 0: RB OE brake caliper relocation kit with largest possible one or 2-piece rotors to fit in 16-inch wheels.

:-) neil

You talkin' about this kit? The Wilwood's HUGE!

Yep. I have those calipers. Unfortunately, I don't have the front hats or rotors.

:-) neil

It's great to see a company that is pushing the envelope and listening to a community like ours for development directions. The problem is everybody needs something different. I really feel that as these cars age the buyers become younger and younger people have less money. Anything that is developed should be lower cost. To do that the stock calipers should be reused. Not only that but even though the advantages of RB are being talked about here there is still a lot of competition for your standard run of the mill big brake upgrade. I really feel that the only possibility left for a successful brake upgrade product is one that increases rotor size front and rear with the stock calipers. If this fits in the stock 16s all the better and many more kits will be sold. Stay flexible by offering standard rotors and the 2 piece deals. I say this because it is the only thing that hasn't been done.

Well I'll be watching to see what's developed.

+1 (stock calipers relocated for larger rotors, fitting stock wheels)

I have a question about the center mount design. One stated advantage is that it allows for cooling air to enter the vanes from both the inside and the outside of the rotor. I can believe this is a significant advantage when running with something like the stock ducting (or rather, lack of ducting), that relies upon an open, passive air intake, largely from the inside of the wheel.

But what if there is dedicated backing plate (ala NTech's) to accept a duct hose running from the bumper lip intakes? This is forcing cooling air from the front of the car to the inside of the rotor, and in that case, is it be better to have a closed, inside-only intake? With a center mount, I wonder if some of the air so carefully gathered from the front of the car would be allowed to escape through the wheel hub instead of being forced through the rotor vanes.

Opinions, (especially RB opinions) please.

Another product idea would be a rotor designed for dedicated ducting, and the ducting system (backing plate, front funnels, and hose) to go with it. See here for more discussion regarding dedicated ducting:

https://www.rx7club.com/showthread.p...5&page=3&pp=15

Those calipers take up much less space than the stockers.

Yep.

Stock replacement rotors and a 4 wheel caliper/rotor kit for 17 to 18 inch wheels would be great!

I would buy the 4 wheel bbk.

Regarding selection, I think there are a couple ideal objectives.

1st, a cost efficient option utilizing the largest 2-piece rotors that will be compatible with relocated stock calipers. A RB caliper should also be offered for those who wish to maximize breaking performance within 17inch rim constraints, but this could come at a later date if needbe.

2nd, a 13" front/rear option with proprietary rotors and calipers. This will allow those who already have the 13" stoptechs etc. to balance out the rears, while allowing those without BBKs to start from scratch with RB 13" rotors and RB calipers, front and rear.

Thanks Howard, Rishie and Warren for getting this ball rolling.

Robert

i am delighted that there's lots of suggestions.

we really have a clean sheet of paper and the best initial decision is where the greatest amount of FD owners win.

i have quite alot of additional info but the post isn't finished and should be up tomorrow aft. it might be of help as to FD product design.

when the dust settles we should have something special.

i do agree, BTW, w an earlier poster that the FD community will not generally lay out the $s that the ZO6 crowd might. that should be a consideration leading to the right initial product.

i also feel that RB will present us w a range of product.

howard

Wilwood SL-6
 

They are large, but with the 325mm rotors they fit with 16" wheels.

Actually they are 327mm rotors (12-7/8 inch):

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/does-anyone-know-who-made-brake-rotors-m2-performance-wilwood-13-brakes-471233/page2/

:-) neil

just for laughs i mounted an OEM FD wheel to my M2 AP brakes.

amazed!

they bolt up but just lightly rub at the top and bottom outside AP cp5200 caliper edge.

i think the issue could be solved w a file.

so the bottom line for you stock wheel guys is, that if you run the right 4 piston caliper, you can run a major league rotor.

i will have alot to say about getting all 4 corners right brake-wise in the next few posts. it's all about coming up w a brake system that is on par w the world-beating chassis.

howard coleman

To clarify your question, if you read my earlier statement again you will realize; The carbon contents may be increased for better heat handling but at the cost of “decreasing” the strength and hardness of an iron – Not increase. Also the purpose of adding alloys is to make up (improve) the strength and thermal stability not the ductility.

Due to the graphite formation in gray iron is in flake shape therefore the gray iron although is excellent in thermal conductivity and “damping” capacity which is like absorbing the vibration (make vibration less noticeable by the driver) but is “not” as good in strength and impact resistance comparing to ductile iron which the graphite is in spherical shape. Ductile Iron has better strength due to it’s ductility and is a more suitable material for structural (stationary) members such as calipers and caliper brackets where no heat cycles are encountered like brake discs.

So an ideal cast iron for a brake rotor is to have the good thermal conductivity like gray iron (flake graphite) but with good strength as ductile iron (spherical graphite). It’s called Compacted Graphite Iron (CGI). It’s a relative new casting process and still is not very popular yet due to more difficult to produce and cost more to make. However RB does offer CGI rotors in some selective club racing applications. (We believe we are the first brake company introduces CGI rotors in performance brake industry.)

http://www.racingbrake.com/Club_Raci...ors_s/4338.htm

Racingbrake CGI rotors helped Tom Long won his North American Title on his Pro Spec Miata race.

http://forums.racingbrake.com/viewto...f4240938ba87fa

We prefer the fine pearlite matrix for better strength and hardness which make rotors more resistant to wear and heat handling.

Thank you for your questions.

[b]BRAKE BIAS,

thread subset BRAKE TECH... a series pointing toward better FD brakes

LONGITUDINAL WEIGHT TRANSFER/BRAKE BIAS, a moving target

longitudinal brake bias relates to just about everything but especially the amount of weight transferred forward under braking. it is an excellent starting point as to understanding what we need in the way of FD brake upgrades.

let's take a look at how it works....


FD.

2789 weight 50/50 distribution plus 250 pounds driver and 1/2 tank of gas. additional weight distributed 62 pounds front and 187 rear.

C6Z06

3130 weight 51/49 distribution plus 250 pounds driver and 1/2 tank of gas. additional weight distributed 62 pounds front and 187 rear.



now let's put the 2 cars in motion...

given: a half G stop. let's quantify the weight transfer.

FD 3038 pounds* .5 (G) = 1519 pounds* .17 which is the center of gravity (17 inches) divided by the wheelbase (99.5)= 258 pounds.

FD front weight 1456 + 258 weight transferred= 1714/3038= 56% front weight

C6Z06. 3380 pounds* .5G = 1690* .16 (17/106) = 270 pounds.
C6Z06 front weight 1596 + 270 = 1866/3380 = 55% front weight

ok, let's stand on the brakes and see what changes

given: one G stop

FD 3038* 1(G) = 3038 * .17/99 = 516 pounds
1456 + 516 = 1927/3038 = 63% front weight

C6Z06 3380* 1(G) = 3380 * .16 = 540 pounds
1596 + 540 = 2136/3380 = 63% front weight

now let's race, 1.375 Gs... quite normal

given: 1.375 G stop

FD 3038* 1.375 = 4177 * .17 = 714
1456 + 714 = 2170/3038 = 71% front weight

C6Z06 3380* 1.375 = 4647 * .16 = 745
1596 + 745 = 2341/3380 = 69% front weight

the longitudinal balance of the FD has gone from 56% to 71% front weight in the above examples... pretty much the same w the Z06.

71% front weight, even w two cars that have been engineered to the max w regard to static weight distribution!

you want ugly?

here's a typical front wheel drive car...

07 Camry
weight 3519. distribution 61/39. w 250 pounds, driver and 10 gallons gas, distributed 50/50.

here's what happens at 1 G

3769 X 1 (g)= 3769 * 26.1 (cg)/109.3 wheelbase (.24) = 900 pounds
2271 + 900 = 3171/3769 = 84% front weight.

'ever wonder why they put those crummy little drum brakes on the back of front drivers?

so how do you engineer for the varying amount of weight transfer?

first you get as much weight in the rear of your FD. i have 53% rear weight. secondly you run a low ride height. i run 25 inches at the top of the wheelwells. mazda has given us a great start on proper braking w the initial 50-50.

finally, you engineer it so the fronts will be capable of handling the most G's you can pull.

all the above said, i believe that the greatest brakethroughs (pun intended) will come from the rear.

stay tuned.

howard coleman

just an fyi, w no promises, but Warren is taking delivery of two new FD rear caliper mounting brackets wednesday.

i believe his plan will be to use a 324 X 24 (12.75 X .945) two piece rotor which according to him is the largest you can use as the length of the E brake cable is the limit.

if he decides to go ahead i assume he would recast the caliper mounting bracket so you can use your OEM rotor and E brake but have an absolutely killer no brainer rear upgrade.

the difference between this and the 12.2 inch RZ setup is the rotor would be lighter, stronger, run cooler, deliver greater stopping force, and allright.... look neat.

Warren did a rear bracket recast extension for the 350Z.

go Warren go.

howard

Would the caliper have to be widened also to use that rotor (stock is 20mm thick)?