rx7tt95

swept area is a combination of not only pad size but of rotor diameter. Remember, as diameter increases, so does swept area. One reason I'm using the monobloc calipers is because they're relatively inexpensive, light, AND their pad is slightly larger than a big red pad. If you've ever experienced the stopping power of the big red kit, you wouldn't care about the extra weight. But with the setup I'm doing, the weight will be significantly reduced.

No biggie about the flak. Most who commented on Dale's project don't really understand sourcing components. Everything I'm using is pretty much OEM. Rotor hats can come from a number of OEM suppliers too, so no issues there. Most problems come from matching calipers to the appropriate rotor sizes. OEM suppliers deal with material grades. Honestly, I thought it would be more work designing a kit. I'm sure it is if you use something like a Brembo 8 piston race caliper, but the fact I'm simply reuniting OEM rotors and calipers using off the shelf hats and the appropriate brackets removes much of the supposed dilemmas. Some of Dale's problems came from the fact he implied that he was copying M2's kit, which he wasn't. Just designing one "like" M2's kit. Wilwoods' hat is an off the shelf part that needs a centering ring to fit the hub. Apply the appropriate rotor/caliper, design a bracket, and viola, you have a wilwood brake kit. Yes, it's a bit of over simplifying, but it's not rocket science (the matching of existing parts.)

As far as cross-drilled being better in the wet, they're mostly designed for out-gassing brake gasses which build up between the pads and rotors. I originally wanted slotted, worried that the cross-drilled would crack. Well, the place that's doing everything races cars and has been doing so for years with street cars HEAVIER than the FD. And they've never cracked a rotor. Basically he said that if I go out and crack a rotor, we'd talk and look at alternatives. The OEM kit is used on cars weighing about 3200lbs, fyi. Once I get the details done and test it on the car, I'll announce it on a broader scale. Right now my work schedule is holding me back. I just finished a trial today and I'm off to Daytona Bike Week tonight with a full schedule next week/weekend as well. I picked the wrong time to be too busy!
Michel

rx7tt95

Forgot to comment about the Brembo/M2 comparison. First, www.n-tech.net has the AP 4-6piston kits for less money. I'd go with them as opposed to M2. Second, either will probably be fine. I'd go with the set that offers the lowest replacement cost on parts (rotors/calipers). FYI, AP now owns Brembo. Ask yourself how easy it'll be 5-10 years down the road to get replacement parts for either. I'd imagine Coleman has a cheaper off the shelf compatible rotor for the AP kit whereas you may be stuck purchasing rotors from Brembo for the brembo kit ($$$). I'd look into the details on that before deciding. I know Nick at N-Tech prefers the AP calipers over the Brembo. You may want to email him to ask why.
Michel

racedriver

I have the F40 kit and i think the replacement parts are way overpriced. Here's what i did. I used two 94 supra turbo rotors (12.7x1.1)and machined the inner circle out a bit. then i had a custom bracket made to use the existing F40 caliper. I made some ss shims to put behind the pads and its ready to go. Performance is equal in all respects., just a little heavier. The Toyota rotorwas $60, the brembo rotor, $300. Big savings, especially when in a racecar

1bad7

anyone use the Brembo big brake kit? i got that one on order

SexyRexyR1

I haven't driven on Kuhmo ecsta's on my FD but my last car had them and i loved them ... great grip and response. I'm about to get a set of 18's for the FD and was looking at the ecsta's again ... Why do they suck on the FD? And what tire would you guys suggest for mainly street and some autoX?

SleepR1

Post your question to this thread:

https://www.rx7club.com/forum/showth...threadid=59566

ML
MDC
www.autosportoutfitters.com/mdc/

artowar2

I agree with what you are saying about matching the components, etc. Don't really understand why Dale received so much crap, but then again, why does anyone get a lot of crap on the List?

So is you source saying that they only have rotors with drilled (or cast?) holes, but none with slots and none with no holes or slots? Or are they just partial to the rotors with holes?

Devilish

It's the rotors that cost so much on the AP and Brembo kits. The calipers are "only" $400 a piece. I'd shell $800 out for a nice set of AP CP5200 calipers if I could get reasonably priced discs to fit. Does anyone else find it hard to believe it cost just as much to make a rotor as a caliper?

rerx7

Yes agree, your tires are the ONLY thing that have contact to the ground. I also believe one of the best upgrades for any car is tires, besides suspension. A tire company have a very good phase "Power is NOTHING without control". I don't use the best tires for street because I do normal driving on street, but for racing I used BFG's g-Force R1 and I do think that they are among the best race tires you can get.
Cheers. =)

rx7tt95

Artowar, sorry for the late reply here...most of the Porsche disks are cast with holes (cross drilled really doesn't make sense when they're cast in no?) but slotted are availible. He's NEVER cracked a rotor, nor have any of his customers. I do like slotted as they seem to clean the pad and deglaze them nicely. But for a bit over $100 a pop for replacements, I'm not going to argue, especially if they work :-) I believe that slotted and or cross drilled/slotted are availible as well, but we're going to try the standard cross-drilled stuff to begin with. I have a track event April 6, so I'm hoping to get them done and tested out well before that event (Homestead, FL).
Michel

SleepR1

That was a quote from Pirelli, and it's certainly true..."Power is NOTHING without CONTROL".

The G-Force R1s were good, the Hoosier A3S03s/R3S03s are even better! They both (R1s and R3S03s) wear about the same, but the R1s are available only in limited sizes...as they're getting out of the sports car racing market.

RX794

Anyone got any info on the 1999 and up FD kits that Mazda Comp. offers for the FD?

artowar2

Yep, I remember reading somewhere that Porsche discs used cast holes, which is supposed to make them more resistant to cracking. I'll ask some of my track-oriented Porsche buddies what their experience has been. I'm interested in your kit, so please keep us posted. I'll let you know what, if anything, I find out about the Porsche discs.

rerx7

Does anyone know the make of the stock brake caliper on the FD if so which model are they? I am more concern on the front, as I am thinking of up sizing the front disc with the stock calipers to save me some money.
Which company provides such upgrade kits like spacers and which size rotor I can use with my stock caliper?
Any suggestions?
Thank you.

artowar2

Read this thread and ask Manny:

https://www.rx7club.com/forum/showth...threadid=51895

rx7tt95

I believe Summitomo makes the calipers but I could be wrong. There are a number of kits in Japan which use larger disks in conjunction with the stock calipers. RX7 Magazine from Japan will be at Sebring this weekend so I'll ask their opinion on which kit is best. I'm sure Takakaira.com could get the kit an ship it to you. Honestly though, the 99 RS kit seems the best for the money. Much larger rotors and calipers with staggered bore sizes.
Michel

maxcooper

Woo hoo! I got my N-Tech AP 13"/4-piston kit today! The calipers are black with "AP Racing" in yellow on the side. The rotors have black hats and two paint stripes (that I assume are temp paint) on the outer edge in one spot. I look forward to figuring out what I broke to cause my car to not start and putting the brakes on to try out this weekend.

My M2 roll bar shipped today as well, but it is not looking good at all for me to make the Open Track Challenge that I was getting all this stuff together for. I still need to finish up some things and then get the car to MazdaTrix for an engine rebuild.

-Max

P.S. I would have posted this response on the original thread on that topic, but Search is disabled. So I posted it here.

Taz

iTrader: (1)

From personal experience, the Porsche 993 tt brakes won't crack. Neither in the Porsche nor in the RX-7. Also, no fading ever with stock Porsche pads and race tires in the RX-7.

rx7tt95

I just had a talk (via email) with Mark Valasik (sp?) and he informed me that the Porsche monoblocs aren't necessarily any stiffer, they're just cheaper to manufacture. Also, the rotors necessary to run those calipers are very heavy and he basically said that it'd weigh to much for an RX7. The 993TT "big red" suffers from the same problem unfortunately so it looks like I'm going back to the drawing board.
Michel

maxcooper

With new pads, caliper mounting bracket, hardware, caliper and rotor, the N-Tech 13" AP 4-piston kit weighs 22.5 lbs per side. I read that the equivalent stock parts weigh 24 lbs, which would be pretty amazing considering how much bigger the AP kit is. I'll be sure to weigh the stock stuff when I get them off the car.

I posted some pics (of my usual low quality) here:
http://www.maxcooper.com/rx7/parts_i...kes/index.html

-Max

artowar2

The initial feedback I've received from Porsche folk with cast hole rotors indicates that the rotors will develop hairline cracks on the surface, but that these do not present structural problems for the rotor as a whole.

Now I have read (I believe at the corner carvers site) about other drilled rotors that cracked and subsequently failed completely (i.e., broke apart). But these were not Porsche rotors with the cast holes.

rx7tt95

Cool Max. I ate dinner with Nick tonight but he forgot to weigh his kits. Honestly, I'd go with his kits if they were a bit less money and I could get replacement parts easily, cheaply, and quickly. I think lots of the weight savings comes from the aluminum hat and aluminum caliper bracket. I'm going to weigh a 996TT disk just to make sure it's as heavy as Mark says it is. I can't imagine the caliper being any heavier than the F50 Brembo either. Decisions, decisions.
Michel

maxcooper

Yes, the caliper mounting bracket is amazingly light in the N-Tech kit. It is nicely machined, too.

A number of decent, less expensive options have become available lately. My AP kit might be a little bit overkill for my needs, but I hope that translates into reduced pad cost over the life of the kit. Pads costs can add up quickly, and with the big pad and a standard caliper like the AP it should keep those costs down. At least this is what I am working on as a rationalization for buying the $$$ kit.

If pads for the APs cost 75% as much and last 2.5x as long... blues for RS calipers are $165 a pair, which equates to $50 of life from equivalent pads on my new brakes. If my new brakes cost $1600 more than the RS brakes, it will take 1600 / (165 - 50) = 14 sets of RS brake pads to come out even (or 5-6 sets of AP pads). Rotor costs should also be considered, but I suspect they are roughly equivalent because I can re-use my hats and the N-Tech rotors and the RS rotors are probably about the same price, I suspect (my guess is $130-ish each).

Is anyone buying this?

-Max

artowar2

Hey Max, once you get these mounted, I am very interested in how the front/rear bias works out. After reading Chris Wilson's comments, I'm a little leery of buying a front big brake kit, then finding out that I'll need a new MC, proportioning valve and rear brakes to get everything balanced...

Re pads, I've been happy with Performance Friction on my stock brakes. I'm running 90s or 93s (I can't recall without looking at the box-- they discontinued one of the compounds for the FD) all around. Seem to be relatively (cryo'd) rotor friendly and the dust doesn't eat my wheel finish as badly as the Hawk Blacks I used to run. PF claims their pads last a long time. Unfortunately I don't get to go to the track as often as I'd like so I can't confirm/deny this... BUT, if they do last a long time, maybe they're cheaper long term-- that's how I justified the initial purchase. So to answer your question, yep, I'll buy that

Damn those APs look good... There's too much stuff I want right now-- brakes, new wheels, one of Atihun's replica hoods, one of the urethane Feed II replica bumpers that rotaryextreme is trying to sell, .... arrrrghh

HedgeHog

Nick mentioned that if you keep the ABS on, it'll assist in front/rear proportioning.