CrispyRX7

iTrader: (139)

dclin et al.,
Just be sure that if the group buy proceeds with the Project Mu 2 piece rotors that replacement rotors are available stateside. It would be a royal PITA to have to go back to Japan every time one needed a rotor. Food for thought.
Regards,
Crispy

dclin

iTrader: (4)

Yes, I thought of that as well. Still, it would be good to find out how much the Project Mus are for reference at the least, if they are available or a future product.

Goracer: I have not heard from Project Mu Japan yet. Could you call Rotary Extreme or Rxecret7 if you have not done so already? See if they are a Mazdaspeed/comp dealer as well, and if they can get the calipers and related hardware. Let me know if you need the parts list/numbers.

Will get with Nick/N-Tech tomorrow.

foko

any news? i just cracked another rear rotor

artowar

iTrader: (1)

Face it foko, you just need a full set of ceramic brakes from a GT2

dclin

iTrader: (4)

Nick was not able to get the front rotors from Mazdaspeed, so artowar had to take measurements (for the front and rear) for him. I have sent the measurements to Nick, so that's where we are now.

Nick does have a customer that has rear '99 brakes, so he has access to that - which is an important point, because with different brake vendors I've spoken too, the same point has comeup: there is the issue of clearance of the caliper and the bolt heads on the hat/rotors.

In other words, in not just as easy as giving overall dimensions of the rotors and having them made, but clearance issues with other components (namely the caliper and bolt heads) need to be figured out too.

I have also contacted other brake vendors for quotes as well, including Essex Parts, Precision Brakes, and Porterfield. Not having a installed set of '99 brakes makes design of the 2 piece rotors difficult, but at least they have to measurements (of the rotors) to give us a rough idea of how much sets will be.

Also, want to prepare everyone for the fact that the rotors will likely have to be custom, as opposed to the universal replacement rotors available from Wilwood, Coleman, and others.

12.19" diameter is a common rotor diameter for Wilwood and Coleman, but is just slightly smaller then the 314mm/12.36" diameter of the '99 brakes. If the brake pad overhangs the rotor, it might cause problems. If the brake pads do not ride too high up in the caliper, them these universal rotors might be usable. An installed set of '99 brakes will have to be examined to figure this out though. FYI, the cost of custom replacement rotors (just the rotors) has varied, and have been quoted at around $150ish, with one as high as $250. Around $150 seems to be what we can expect them to be.

AP Racing does make a 315 X 32mm rotor that would be perfect for the front, but Essex quotes replacement rotors (just the rotors) at $380/piece. Ouch. They do not have a 315 X 20mm though (they have a 315 X25.4mm, but unable to figure out at this point if the thicker rotor will work. Due to the cost of AP Racing rotors though, custom Coleman or Wilwood rotors makes sense for the majority of us).

Daniel

foko

hmmm....i have a set of 99 rears installed and could figure this issue out. unfortunately i'm leaving town for a week this weekend and i doubt i'll be able to look at this issue closely before i return. i'm sure i'll be able to figure whether the standard size will work pretty easily.

maybe someone else who has them installed could get to it sooner than i???

custom rotors is a bad idea in my mind.....that simply means a headache every time the rotor needs to be replaced. if the standard size will fit, i think that's the ticket.

i'll try to get to this ASAP, but i'm unlikely to be able to until about 7-10 days...


fabian

foko

now there's an idea.....

dclin

iTrader: (4)

Yes, if you can see, that would be great. Max has the same setup too, so if you have time to look Max, I'd appreciate.

Nick/N-tech does have a customer with '99 rear brakes, so it's just a matter of having him go to the shop. However, I don't think he has the '99 spec front brakes though.

The problem with universal rotors is there is only one that is the correct diameter (actually, a mm larger). But at $380 per replacement rotor, the AP Racing 315mm X 32mm rotor is on the pricey side. Given that custom HD rotors should cost around $150 or so, custom rotors are still more economically palatable.

The closest universal rotor is short by just a hair over 2mm in radius ('99 RS/RZ spec is 314mm/12.36" diameter, the closest universal is 309.6mm/12.19" ). If the pad extends up to the edge on the stock 314mm (12.36") diameter rotors, it will obviously hang over the smaller diameter 309.6mm/12.19" rotor, exposing a small portion of the pad's swept area.

According to the shops I spoke with, this may result in hot spots at that point, and the pad could possible crack. Not something I'm willing to take a chance on at all - brakes are one place I'm not going to make any comprimises in saftey.

So - if the pads do not extend all the way up to the edge of the '99 stock rotor - there is a chance we can getway with the slightly smaller universal rotor. We just need someone with this setup to see if this is the case.

Having said all that, some things to consider:

- The hats will use a industry standard bolt pattern (likely either the 8 bolt 7" B.C. or 8 bolt 7-5/8" pattern), so you can order the slightly smaller universal rotor when replacing the rotor in the orginal set - but you do this at your own risk of course. Maybe the pads can be trimmed? Again, we'll need to look at the way the pad sits on the '99 spec brakes before worrying too much about this.

- Coleman custom rotors are not that much more then their equivalant universal rotors - roughly $40 -$50 more per rotor, depending. I spoke with them earlier today, and you can order directly from them. I forgot to ask how long lead time typically is though. I'll find out Monday.

- and.... I lost my train of thought....hehe. I'll post again when my brain is less mushy.

maxcooper

I just looked at my car. The pad is pretty near the edge. There is a 1.5mm chamfer (eyeball, not measured) at the edge of the rotor, and the pad goes just about exactly to the edge of the flat as best I could tell by looking at the swept area. The pad does not seem to hang over the end of the chamfer, as the wear stops at the edge of the flat and I think my pads would have worn enough to be at least half as deep as the chamfer, and probably deeper than the chamfer at this point. It is possible that a little hangs over but gets broken off before it can wear the rotor or something though, I guess.

Anyway, I suspect that a 4mm smaller diameter rotor would not work with the caliper position and pads as-is. I could move the caliper in a bit, or cut the pads so that they don't wear the edge.

I think my pads do hang inside the swept area, as they have a flat bottom and is a bit taller than the swept area. Perhaps I should have carved them a bit, but this doesn't seem to be causing any problems so far.

I am a bit concerned that there won't be enough clearance for the caliper bolts if they are very near the swept area on the rotor. Perhaps I need to take some measurements to help avoid problems in that area.

I am leaning toward preferring Coleman custom rotors at this point. I think I've got a pic of a tape measure on my RZ rotor, so I'll try to look that up to verify the size. On the other hand, if the diameter of the "standard" rotors is measured to the edge of the swept area and not the entire rotor (including the chamfer), the 310mm might work.

I don't know if Porterfield sources their rotors from Coleman or not, but I noticed they do custom rotors when I was looking at their web site the other day. They are local to me, so I could coordinate with them if they turn out to look like a good source.

-Max

FD:)

I have a few sets of RS brakes.
A set on my RS, a set on my '91 type R and a couple of spare sets...

The rears are the same width as '92 just the diameter is bigger. The calipers are the same just a longer bracket casting.

Front disks are much fatter and the calipers a little different looking and wider...

Pads are interchangable with '92

If you have 17" wheels you might need a 5mm spacer for the fronts to clear the caliper. I found this to be true even for my Mazdaspeed 17" wheels.
(they are pre '96 so latter MS 17's should be OK?)

You can just cut the lip off the '92 dust covers and they will fit. (hard to get the real dust covers because you have to take the whole hub. I just get the disks and calipers... freight is cheaper)

Here's a pic of the fronts on my R1 with 18" mazdaspeed wheels. (No clearance problem with them )
Look massive on 17s but don't look so big on 18s. .
A note on these wheels. F18X8 1/2 R18X9 1/2
"Mazda Racing Team" Quite rare I recon. Only seen one other set on the pace FD at a GT race in Japan last year.



Glen

FD:)

Rear

CrispyRX7

iTrader: (139)

Datapoint for you guys. Mandeville fronts I use which utilize Colman off-the-shelf rotors and the "modified" factory calipers does leave the pad overhanging by about 1-2mm over the edge of the rotor. Far from optimal when it comes to maximizing use of the pad surface but on the plus size I've been using these brakes on the track for more than 3 years now with no ill effects either with rotor cracking or pad disintegration (Hawk blues) So I dunno how much weight should you put on the argument against going with an ever so slightly smaller rotor if it can be bought as an off-the-shelf unit simply because you get a mm of pad overhang.
Not perfect but ok vs custom units or Brembo rotors at $380 a pop?
FWIW
Crispy

maxcooper

Here's a pic I took of the Mazda RS/RZ rotor diameter measurement. It looks like it is between 12.25" and 12.3125". But it wasn't a very exact measurement with that measuring tape.

Given CrispyRX7's experience with the Mandeville fronts, perhaps the little bit of overhang is not such a big deal. $40 replacement rotors would be nice if they will work.

-Max

dclin

iTrader: (4)

Thanks for the input guys - that's alot more reassuring given there are those with just a tiny bit of overhang and no ill effects.

I was using the 314mm diameter given somewhere else in this forum, and 314mm = 12.36" - but if it's a little less then that, then that makes things much easier for us.

Just to reiterate though, the $380 is for the 'universal' AP Racing rotor (315mm X 32mm). It appears AP rotors are highly regarded, and have the price tag to match. The Coleman 'universal' and 'custom' rotors are significantly less.

Max, let me first get a quote from Porterfield. If they turn out to have the best deal, then we can work out the details. Thanks!

GoRacer

iTrader: (2)

Sorry, I keep forgetting to call them but I did e-mail both of them although neither of them ever replied.

dclin

iTrader: (4)

Thanks Goracer - I think we've got some options forming up, so we can go to Project Mus if these don't pan out.

Ok, Precision Brake Company is the first to give ball park numbers. They understand the complexity of our buy, and have structured it to be as simple as possible:

Note that these prices include cross drilling, slotting, or any combination. Black anodizing of the hat is standard, and they have agreed to do either red or blue at no additional cost. These prices are based off of a diagram and measurements I sent them, and they will still like to get actual samples in before cementing the cost. These prices should stay the same though, barring anything unusual with the OEM specs.

The rotors will be custom, as they advise against using a different diameter then what was intended. I will clarify whether these will have a universal bolt pattern, for those that want to use the slightly smaller diameter universal rotors from Wilwood or Coleman upon replacement. I forgot to ask how much the custom Precision Brakes replacement rotors will be, will do so tomorrow.

The hats will be custom as well, and all relevent dimensions will match the OEM rotors.

Here is a pic of a Precsion Brake custom 2-piece rotor, though ours may not exactly like this due to design differences (main thing being the hat size, to clear the calipers):



If we go thru Precision Brakes, I will arrange another GB thru Jason/RX7 Store for the OE calipers/hardware. Jason has shown interest, and we'll pick up on that at the apprpriate time.

N-Tech is expected to have numbers tomorrow, and I'll post those to compare then.

artowar

iTrader: (1)

Wow, these prices look a lot better!

maxcooper

Daniel, thanks again for your continuing efforts to find us some good brake options. It is much appreciated.

The PBC option looks pretty good. It looks like they are using curved vane rotors in the picture, which should be extra good for cooling. $450 for a set of rear rotors ($250 each - 10%) sounds quite reasonable to me at this point.

-Max

CrispyRX7

iTrader: (139)

dclin,
Any way to get the rotors without the X drilling if this arrangement goes through. We all know the deal with using xdrilled rotors. And to be an even bigger pain could one forgo the anodizing and just get the hats in plain AL finish? Just floating some questions. But this is looking good.
Regards,
Crispy

dclin

iTrader: (4)

Yes, you can get the rotors unslotted or drilled. They will be made on a custom basis, as there are no universal hats or rotors to use. (I will make sure they use a standard rotor bolt pattern though, so you have the option to use the slightly smaller diameter off-the-shelf Wilwood or Coleman rotors when you need to replace them)

They just set one base price per rotor (does not matter front or rear), assuming the works - cross drilled and slotted - and you can have it just slotted or just drilled too. The price remains fixed (besides the discount of course), and this makes it infinitly easier to manage. I'll have to ask other vendors if they can follow the same format.

The hats can be left natural aluminum as well, and will actually be easier for them of course. Black is their standard color, and they have graciously included red or blue at no additional cost as an option in this buy (they say they normally charge for these optional colors).

These are closer to the prices I was hoping to get in the beginning, and I don't see any problems making the 10% discount, with 20% a good possiblity. Because they are counting per rotor with reasonable goals for each discount level, it's much easier to reach a good discount.

I'll be checking with NTech shortly for their prices, and will post here.

dclin

iTrader: (4)

Update on the Precision Brakes. They will be directional vane, and likely have a universal bolt pattern. Final details will be ironed out when we get to the point of sending actual '99 spec rotors in for them to examine.

The natural aluminum finish will be availabe - they will just clear anodize the hat in this case, for finish durability.

The custom replacement rotors are going to be roughly $149 to replace. These are the correct OEM spec diameters of course, and if a universal bolt pattern is used, you may be able to use the slightly smaller diameter universal rotors from Wilwood and Coleman - at your own risk of course.

Contacting NTech now...

am3210

He's a price and part numbers I received from Corksport on the rears.

The calipers are $225 each. The rotors are $110 each.
Caliper Part # F1Z4-26-98Z
Caliper Part # F1Z4-26-99Z
Rotors F124-24-25XA

CrispyRX7

iTrader: (139)

Hate to be a nag...but any progress?
Regards,
Crispy

dclin

iTrader: (4)

Talk to Nick yesterday, and he says he still needs a couple more days to get numbers. We'll give him a few more days and, if he still does not have anything, then we can decide if we should go forward with the Precision Brakes solution.

Thanks for the numbers am3210, that'll be handy to compare to GB numbers.

am3210

dclin no problem. Guys I thought the killer brake combo was suppose to be RZ's in the rear with AP upfront with the 929 Master Cylinder. Have things changed? I know the AP's aren't cheap.