Hi Guys

I am after a better brake setup for my FD Race Car.
Currently has:
Front: 325mm x 28mm Alcon Rotor, 4 Piston AP Caliper
Rear: 306mm x 28mm Alcon Rotor, 4 Piston Harrop Caliper

These brakes are now to small, I am frying the front rotors pretty fast.

Are thereany kits out there bigger then this?

Ash

 

What are you doing for the cooling? What pads are you running? Bigger is not always the better. And last one is what type of racing? Road racing? Time Trial?

 

Has Brake Ducting, Running Pagid Enduro Pads (15)

Road Racing, here is the car and track
https://www.youtube.com/watch?v=DFH6zYLgJ2w

 

I think you may want a wider rotor - thicker fire path and more air gap. Something like this maybe;

RX-7 FD COMPLETE FRONT AND REAR BIG BRAKE KIT


There is a 355 x 32mm front kit with a 6-piston caliper;

Rotora Brake Kit


Todd at TCE makes track kits for RX8 with a 355 x 32mm rotor with the larger W4A Wilwood caliper - not sure if he has done anything similar for FD RX7 kits or not. Todd is a great guy and a racer - give him a call if you need some technical advice on a new setup.

RX8 - Kits

What ever you do make sure you get a track rated/designed kit and not something designed to just look big and impressive on the street.

 

What kind of cooling do you got on the front? Just a hose going to the calipers?

A good solution is a complete ducting with a frame around the disc. Have a look at damian's break setup.

Also change pads. Enduro pads will most likely produce more heat. Get something like Ferodo DS3000 or the best Hawk pads out there(Don't remember there name).

I run 6 pot AP calipers with 330x32 disks and have not had any warping issues at all up front. Not even after 30 hot laps. Stock FD breaks would be hot after 5 laps on that track.

JT

 

Hi
Yes have the ducting to rotor center and shrouded
Had to go to enduro Pads, the Pagid RS14 fell to bits. Ferodo DS3000 are similar to the RS14's, however I find the Ferodo Ds3000 very agressive on Rotors

Ash

 

Most serious race pads with a CF of 0.60-0.68 uF such as, but not limited too;

PF01
Carbotech XP 10 or XP12
Ferodo DS3000 or DS3000 Plus
Hawk DTC-60 or DTC-70

...are not going to be very rotor friendly. Depending on your driving style and pads you will most like crack a rotor before wearing it to minimum thickness. Always good to have a set of spare Coleman rings handy.

The better question maybe what is getting too hot, the pads or the fluid? I had a set of SS shims laser cut out of 0.022" stock to help reduce heat transfer from the pads backing plates to the pistons. I have seen them cut out of Ti as well, but 304 SS has a higher resistance to heat transfer. This will help to keep the fluid cooler.

BTW, what fluid are you running? I ran Ate Blue fluid (not the best) on a big nose heavy FWD car with those SS shims behind Hawk Blue pads working 332 x 32mm 2-pcs rotors and it help a lot. Now with a more aggressive pads like the Hawk DTC-60 or 70, I would have switched out to a fluid with a higher dry temp rating. such as; AP600, Castrol SRF, Motul BRF600 or AP608.

 

I would switch to thicker rotors, not bigger diameter.

How is your brake balance on the car. Is it possible you have too much brake in the front and it's killing the front rotors? I would switch braking to the back using whatever proportioning method you have until you start locking up the rear and then one notch towards front. Of course this is if you already don't have this done. It's just odd that you are killing just a large size brake system. Something is not right.

I am a believer of sticking with the 4pistons and not switching to the 6pistons. It's a bit of waste of money for no gain.

 

FC Mandeville Brakes

FC and FD calipers are the same

 

Very good point on the brake balance. Which brakes front or rear lock up first on slick pavement?

Huge diameter rotors and 6-piston calipers are also heavier so you have more unsprung weight to deal with. They are typically over kill on a light weight and well balanced chassis. And yes wider rotors do add a bit more weight, but they have the added thermal capacity due to the wider fire path thickness and they have a wider cooling space so the benefits out weigh any determent.

 

Nice driving.

You are getting the most out of a very fast car on short course with a major down hill brake zone so you're going to crack up brake rotors no matter what you do but clearly the following will help keep the rotors from cracking as fast:

.28 isn't that thick so go thicker if you have room in the caliper

Add massive inlets for your brake cooling hose ideally the same diameter as the hose itself that leads to the duct/plate thing on the back of your rotor. If you don't have the plate installing one will help a lot.

Give up some braking with the enduro type pads like PFC 97s you are already using will automatically move the bias to the back if you're using aggressive rear pads like PFC 01s in the rear.

How long are the rotor lasting in terms of hours?

 

Thanks for the great feedback guys.
The car can run its fastest laps for about 3 laps before the pedal starts to get a bit long. We are doing upto 15 lap races, but might start doing some enduro races which are 120 laps split into 3 x 40.

Brake balance is controlled by a dual cylinder pedal box, currently adjust too almost full rear.

Initially the car was designed to run on 16 x 7" rims on a R compound tyre, now we have gone to a 18 x 10" and slicks the extra braking load is killing the rotors.

I dont think any road type caliper or rotor will cut the mustard now, time for something decent like V8 Supercar braking system. We are doing the same lap times as the V8 Supercars!

Racing Brake Calipers
brake calipers

Alcon, do a kit, hereis the front kit. This is a semi-race caliper he isgoing to quote this kit with a full race caliper. Mazda RX7 S6, 365x32mm disc, Monobloc 6 piston caliper
The rear kits is slightly smaller

Ash

 

Don't know the rotor diameter, but there's a complete Harrop set-up over here with minimal usage off a FD - won't be cheap! - that could cop any of the abuse you're contemplating. Might possibly have the Alcon ones too....same as on Mark Porter's (RIP)....old car.

Brembos are on the car now I believe, to complete the schizophrenia. Pro-Duct in google should give a contact if interested!

 

With any of those "bigger" calipers, just make sure you are not exceeding your current master cylinder fluid flow capability or you will need to up size that as well.

 

Ok, I know we keep going back to this: Can you lock up the rears before the fronts now that you are proportioned mostly to the rear? If you can't I would say the master cylinder sizes are perhaps not right. I just want you to make sure everything is all good on the easy/cheap stuff before you go out and drop a few thousands on a new setup!

Cheers

 

Yes I can lock the rears if I turn the bias more towards the rear.

But the bias is very finely set, I do like to trail brake deep into a corner.

Can't ignor the fact the brakes tiny for the times we are doing. They were never designed to run with big slicks. Also the track I am racing on is renowned for being very hard on brakes. The braking into the last turn has the highest braking G force of any track in Australia. So there is 1 stop from 160mph and 2 stops from 130mph and 1 stop from over 100mph. There is very little time for the brakes to recover as the track is only 1.5miles long.
Ash

 

Alright, well given that you have everything else checked out, I would go with thicker rotors over bigger diameter. 28mm is about 1.1". Perhaps 1.25" (32mm) or 1.38" (35mm) although the only manufacturer I know with 35mm is Wilwood at the moment.

One thing you will gain with going to the 6piston caliper is a gain in heat transferred from the pads to the caliper. However this could cook your fluid pretty quick which would give you the same pedal feel.

Do you know the weight of the car and the power you have? Front to back weight would be helpful too! Also do you have any information on the front and rear brake temperature? Do you have access to a temp unit to measure the brake temps next time you are on the track (if it is not off-season for you guys down there!)

Since you already have calipers with some brackets, you might be able to get calipers and rotors to replace what you have instead of a full kit. I find that the kits are typically way more expensive since they are charing you through the roof on the bracket.

 

Hi Ash,

In my track only FD I run the Brembo GT kit currently with the stoptech rotors. These rotors are 332x32 and I have a 3" hose off the nose of the car to the inside of the rotor. I run the Hawk DTC-70 pads front and rear. Actually there are two single turbo FDs (~420rwhp) running this brake setup locally. We both also run the 99 Spec rear rotors with Wilwood Dynalite calipers and use the 1" bore 929 master cylinder with a proportioning valve. We mostly do sprint racing here in Northern California with race times in the 30 min range. The pedal is firm throughout. I ran 6 weekends on a single set of front rotors maybe 12-15 hours.

Additionally there is the option of having rotors made to your specs. I have heard good things about Coleman Racing.

Guy

 

Back to the setup. As you are runing slim rotors and only 4 pot calipers. Id try and upgrade them to bigger rotors, 6 pot front, 4 pot back. 356 front and back with as tick as you can get rotors. Redoo the ducting. Make ducting to both the disc and the caliper. With the heavy breaking you are getting and upgrade and some realy good break pads would be the way to go. Remember the enduro pads will generate more heat then for instance DS3000 pads.

JT

 

Thanks.
I was running a normal race pad Padgid RS4-2 (Front) and Pagid RS14Black (rear) but they would fall a part. After a few race meeting you you pull the pad out and the friction material would actually fall off the backing plate, hence we went to an endurance style pad. RS15 and RS4-4
Pagid Brake Pad Products.

DS3000 are a good pad but even more aggresive on rotors

Ash

 

This is the combination we will be going for:

Email from Alcon:
For front, we can go up to 375x35.6mm which are current V8 Supercar sizes.

For rear, we can also run V8 Supercar - 343x32mm (different spec to the front already quoted).

Assuming these sizes will work, prices are:
Front: $+gst per side. (V8 Supercar rotor, Billet alloy bell - floating, Alcon bobbin drive hardware).
Rear: $+gst per side. (V8 Supercar rotor, Billet alloy bell - non-floating, Alcon bolt hardware).

Rotors and mounting hardware are in stock, we just need to make up bells for you. We'd need information such as offset required etc but I'm sure we can work all that out together.

And these Calipers
Racing Brake Calipers

Ash

 

Looks like you've got a serious car, nice driving! What gear box are you running?

We may have something that will suit your needs. We use AP 4 piston race calipers (CP8350) with AP J-hook discs that are 325x32mm and utilize 20mm thick pads, which should be able to handle anything you can throw at it.

Below is a link to more information, feel free to shoot us a PM or email if you have any questions.

http://www.sakebombgarage.com/FD3S-brake-system/

Regards,
Dan

 

^^^Not quite sure whether he's going for V8 Alcons or Brembos?


If it's the former at least - and having sold some, the pads on those are substantially larger than the APs you mention......30mm thick and 153(?) long, 50 odd wide, bloody heavy and expensive too.......overkill imho on a car that's not likely to do 6hr (or 12hr!) enduros and probably 400/500kg lighter.

 

Thanks Guys
The Rotors are the actual current V8 Supercar rotors, front and rear. Front is full floating
The Calipers are not, they are
Front: Brembo Monobloc 8 piston (has 4 individual pads per caliper)
Rear: Alcon 4 piston racing caliper, offset pistons

It may seam a overkill, but the car is doing supercar lap times over 15 lap races. Also, setting the car up to do the Wanneroo 300 next year, which is a 300km (120 laps) enduro race. The lap times in the enduro are also current V8 Supercar/GT3 Porsche cup lap times.

I dont see many cars out there which do these lap times with small brakes. dosent matter what type of car it is.

At least with this new setup Rotors and Pads will be easy to get

Ash

 

About the pads breaking up, they will do that due to the heat.

With bigger brakes and new pads you will bee good to go. I have probably driven 2000 track km with my DS3000 pads and brembo disc. They will be changed now for next year But still got life in them.

JT