elwood

iTrader: (1)

I've been researching components to make a big brake kit for my FB track days car, and I've finally found a setup that satisfies all my requirements:

- fit inside my 15" wheels
- 4 piston caliper from a highly regarded manufacturer
- correct, balanced piston sizes (30mm/34mm)
- 2-piece rotors (hat and disc) so I can get a big rotor with my OE 4X114.3 bolt pattern
- curved vane rotors

What I used:
hub: FC 4-bolt w/ReSpeed bearing adapter
hat: Custom 1 ½” spacer with integral hat
caliper: StopTech ST40 30/34
rotor: Coleman Racing custom, 305mm dia, 32mm thick
caliper brackets: custom made, radial mount

It’s been about 5 months since I dreamed this up, and I finally have the brake setup installed. The largest rotors that would fit inside my 15" wheels were 12". Running fitment calcs with caliper templates is tricky. The curvature of the calipers didn't match that of my wheels, so I lost a little potential rotor size because of it. It's also part of the reason I had to grind some material off the OD of the calipers. My spacers are 1.5" thick and serve as a hub dust cover and rotor hat. I had them hard anodized for corrosion resistance. The trickiest part was the caliper brackets. My machinist nailed them on the first shot -- perfect fitment, no drag, no shims. The calipers are radial mount, so I used the same studs StopTech uses in their kits. They were expensive, but worth it.

Haven't driven the car with this setup yet, but I'm encouraged that everything fits and I don't hear any grinding noises when I spin the wheels.

elwood

iTrader: (1)

Two more pics.

Jeezus

iTrader: (4)

sweet man! how is it?


edit: jumped the gun on how is it, lol, i got excited

Kentetsu

Very impressive man!

elwood

iTrader: (1)

Kentetsu,

Thanks. You lucky dog -- you're right by my favorite track -- Grattan. I'm near Waterford Hills. It's like a road race course, only smaller .

Rico Suave

iTrader: (1)

very nice indeed, KUDOS !

woodonastick

iTrader: (1)

wow that looks really really nice. should i be afraid of asking the price of the set up? btw nice wheels. i have a set of those myself. waited a good 7 months

elwood

iTrader: (1)

Without including all the little knick-knacks:

Pair of Calipers $700 (normal pricing is $1000, but I got a special deal)
Pair of Spacers $300
Pair of Caliper Brackets $140
ReSpeed Brake Conv Kit $175
Custom Rotors $150


I think that covers the major stuff.

As for the wheels, mine are the ProRace 1.2. I ordered the ones with the deeper spoke dish, but that's what they sent me and I decided to live with them.

RX3SP

iTrader: (62)

WOW! That's a nice setup!

680RWHP12A

very nice

mazda6guy

iTrader: (1)

That's so hot man!

dj55b

iTrader: (2)

thats very nice indeed ... how would you say these compare as oppose to getting the Caliper off a TII and slotted rotors for t2 also? What have you done to the rear?

elwood

iTrader: (1)

As compared to a TII conversion, my setup is a lot more work to make, a lot more expensive, but offers nearly twice the thermal mass. This means greater fade resistance for track use.

I haven't done anything to the rear (or the master cylinder / booster, or the brake lines), which was a key part of my objectives. I wanted to limit the scope of work -- otherwise I'd end up with a totally new braking system and all the associated extra work. Besides, I have a GSL-SE rear, which seems to be working fine. I haven't had any overheating issues with it, so the plan was to leave it alone.

I selected the front components -- rotor diameter and caliper piston sizes --specifically to maintain the OE front/rear bias. Most of the kits I've seen are front-biased because the aftermarket calipers available usually have big pistons ~1.75" / 1.88". Being front biased is safe but will increase stopping distance slightly since you won't get the optimal work out of the rear brakes. A prop valve won't correct this, since it's job is to reduce the work the rear brakes do -- not increase it.

The TII conversion is very good choice. It maintains proper bias, the parts are readily available (I found the ReSpeed kit to be excellent quality), and it's a true bolt-on conversion. The only thing you'll need to wrestle with is wheel spacers to put your front wheels where you want them.

BTW -- I spoke with Roger Mandeville about his TII brake upgrade. It is possible to get more brake out of the TII caliper. He no longer sells the kit, but it consisted of spacers to widen the caliper so you can use thicker rotors, caliper brackets that spaced the calipers further outboard, and bigger rotors. If you want to do some work, all these parts can be made yourself. This conversion will throw off your front/rear bias slightly, but it will still be very close to optimal.

dj55b

iTrader: (2)

Thanks for that reply,

You covered all the point that i was thinking about. Because alot of people don't think about the brake bias effect resulted by just upgrading the front ones to bigger rotor and calipers as it is the cheapest without looking at the rear. I just have one more question thought, I noticed from one of the pictures that you have a brake cooling duck attached and I was woundering to where do you have the duck going to exactly behind the rotor. I've been thinking about doing this mod myself just wasn't sure exactly where to feed it to. If you can snap a few more pictures of that, that would be awesome.


Btw ... what do you have running this car? turbo 13b?

elwood

iTrader: (1)

Good eye. The ducts were setup for my old GSL-SE brakes. They aren't currently connected. I have some spindle ducts from that old setup (Mazda Competition) that I could adapt, but I havent done it yet. I have a Mariah narrow body front air dam, and I take the air from the fog light recesses. Hoses are 3" silicone.

As for an engine, I'm working on installing a Cosmo mill with single turbo conversion. I basically have exhaust and ECU calibration left to go. My goal is to have it running by May.

dj55b

iTrader: (2)

sounds like a good plan to me. If you can still provide pictures of that ... I would really like to see that. I was planning on welding something there, but just wasn't too sure where to attach it.

elwood

iTrader: (1)

Here's the picture of the spindle ducts from Mazda Motorsports. It bolts outboard of the caliper bracket through the 4 mounting holes. The attachment for the cooling duct routes forward in car. These things aren't cheap, but they save a lot of fab work.

RX7145

iTrader: (1)

Looks VERY nice. A lot of work. And you have a "kit" that no one else has. You are not going to have any fade with that set up. My set up (which is smaller 11.75in and .81in) never faded at the track. You have more power, but I still don't see them fadeing.

The only problem I had was pedal travel. It took so much "stroke" to move all that fluid. I put in a two stage master and that fixed my problem. My back brakes with a aftermarket prop valve would "skip" under hard braking so I know the rears are working.

Again looks very nice!!

dj55b

iTrader: (2)

AH ... that makes sense now, i've never been able to find a picture of them before and didn't know who made them but I saw the ones offers for the FC's and they have a 3" hole cut and pipe fitting right in the hole like this:



so i was trying to ticker with the idea of trying to get that on. would you have any pictures of them from the other side? Also is that sheet metal or is that a plate that mounts to the hub

trochoid

iTrader: (6)

Excellent fab work. It's always a treat to see a successful upgrade come to fruition. Other than the total price tag, I would think you could develope some interest in this upgrade for the guys that are running serious track cars. Once you have the car on the road/track, I would be interested in seeing what kind of stopping distances your upgrade achieves form 60 to 0 and 100 to 0 mph. If you are willing to do this, please include tire type/size/specs along with air pressure and ambient temperatures and brake pads.

I just recently aquired the ReSpeed kit and am looking forward to seeing what kind of braking improvement I achieve along with wider/better tires.

Keep up the great work.

elwood

iTrader: (1)

Thanks for the compliment on the work -- it took a lot of calculation and shopping.

As far as improving the stopping distance, I don't expect this conversion to affect it. If the car's OEM braking system is properly biased front/rear (which I think is the case), and the brakes can generate enough torque to lock up all 4 wheels, there is no improvement in stopping distance available through brake upgrades. This upgrade will give me better fade resistance and maybe better pedal feel -- although the pedal feel was pretty good to begin with.

The best anybody can hope for in these cases is to not make the stopping distances longer. If you check the numbers on almost any tuner car with a big brake upgrade, you'll see the stopping distances increase. Culprits are screwed up front/rear bias (see my earlier post) and excessive negative camber in the front. I think I've avoided the bias issue, but I will be running a lot of negative camber, which I deem to be a worthwhile tradeoff for initial turn-in and even tire wear.

As for the numbers you requested -- sorry but I don't have the spare tires lying around to get them. Getting that data on a non-ABS car means flat-spotted tires, which I can't afford.

elwood

iTrader: (1)

No pics from the other side, but look at it like this: These things are basically designed like the top of a cookie tin, with the lip fitting right up against the inner diameter of the rotor on the inboard side. The object is to ram as much air inside the rotors as possible so it will spin outboard through the cooling vanes. I think the routing of the inlet tubes is the most difficult part. You want them to position your cooling hoses so they have a relatively straight shot at the spindle and don't restrict turning circle too much.

elwood

iTrader: (1)

Thanks for the info. I considered going with the 11.75" rotors, which would have made them more of a standard part and therefore much cheaper, but I had to go with custom rotors to accommodate the 51mm pad annulus on my calipers. I wanted to use these calipers because StopTech will provide custom bore sizes to keep the bias correct. Since the bores are relatively small (smaller than the 36mm FC bores), I'm hoping I won't have a pedal travel problem. What are your bore sizes?

RX7145

iTrader: (1)

I'll need to look up the P/N on my box then cross it with Outlaws website. I know the bore sizes were different...

I also had the stock 12A master cyl. Can't remember if it is the same as a -SE master.

I'll get back with you tomarrow.

elwood

iTrader: (1)

From the rotor size and the caliper brand, your setup sounds like the Sevens Only setup. Am I right? It looks like they discontinued it. Any idea why?