Custom big brake kit ?
 

Hi folks.

Anyone ever tried fitting some bigger brakes (calipers and rotors) to RX7 ?
Any success stories ?

Sometimes there are really nice deals going on the eBay for different setups, like this one for example:
http://cgi.ebay.co.uk/subaru-impreza...QQcmdZViewItem

Question is - does anyone know what should one be awared of when trying to take up on such a project ? What else may be involved besides getting the right bracket fabricated ?

Thanks for your input.

Everything about Brakes by Grassroots Motorsports A must read!

Thanks Damon!

But my problem is that I had sticking front calipers, which I have had rebuilt and rotors resurfaced (to remove warpage). It only took me another track session and they began sticking again and after coming in the pits it ofcourse caused my rotors to warp again. So I now need new calipers, rotors and most likely also pads in the front and would like to get soemthing better.

you might want to look at the mandeville big brake option. howard coleman and maybe john magnusen(sp?) posted some info about it in the past.

www.rx7.com >products>1933+ RX7>Brakes....Greddy big brake kit for RX7s 12" rotors and oversized calipers i believe..

Yes, I read about that. I think someone has a set for sale and I already PM him.
However, I am not limiting myself to 16" wheel option. I can happily live with bigger brakes and 17" wheels ;)

Stoptech makes an FD big brake kit that is balanced to the stock rears. Or you can order it set up for balance with the 99 spec rears. This way you get proper front/rear balance and can keep your parking brake.

He's most likely seeing if he can fit some of the more inexpensive kits from eBay rather than the $2k price tag of the current kits.


cruiser,

The two main issues you'll have to contend with is the brake balance from the different front brakes and the stock rear; and then mounting brackets strong enough to hold the caliper in the correct place. Since you track your car, you better have a machinist you trust with your life to do some brackets. ;)

Otherwise, you should just pay for a BBK kit, or get some real track pads and just alternate those and pads for the street.

Hi Mahjik :)

What I am looking at are Porsche 993 front 4-pot calipers with a mating 13" rotor. Brackets are made in Germany by some company and they supply these adapters to many aftermarket BBK's. But the end price wouldn't be much lower then some of the used BBK's going for sale here.

I think I will just keep an eye on the for sale section and grab myself a good deal if possible. My biggest concern is the weight of it all and shipping to Europe.

On the other hand, I am thinking of selling my FD and going with an E46 M3 SMG :D ;)

Decisions, decisions, ....

I think the main challenges are finding rotors with the right "offset" and making caliper brackets that can work for you (make some brackets). I don't know the critical dimensions or I would share them with you.

-Max

There are a few people here who have Porsche calipers on their cars, however I don't think any of them are the original owners who had them done (damian being one). All of them have custom brackets and most likely all done from different sources.

As for the E46 M3 (for tracking) without spending some money on it; I don't think you'll like it as much as the RX7.

I think you've got a problem not related to brake size.

What do you mean by "sticking"? Pads sticking to rotors? Pistons stuck in calipers?

If I had to guess, i'd say you've got crappy pads that are melting and leaving uneven deposits on your rotors.

With the right pads, stock brakes can be very capable on the track for a long time.

I think you're opening a big can of worms trying to "piece" a kit together. There will be several fitment issues to contend with.

1. If you just get "calipers" from another car, the piston sizes may totally not match the weight of the 7, your master cylander size, the rear piston sizes.

2. You can get aftermarket rotors, but it'll be unlikely that an off the shelf rotor hat (for 2 piece rotors) will be available, so you'll need to do engineering drawings to get a brake manufacturer to make you some at a significant cost.

3. THEN, you got to have brackets made to hang the caliper, and that meansd gettimng the spacing right in 3 dimensions..... distance out from the hub (minus the existing bracket), distance left to right (depending on where your one-off rotor hat locates the rotor), and factoring in the fact that most aftermarket calipers have bolt holes on the bottom rather than the side. Good luck getting this right the first time.

4. Gotta make up your own custom brake lines that will mate the OE mazda fitting to the banjo bolt or whatever is on the new caliper. Oh yeah, and fab something to get the thing to clip on to the shock bracket.

Screw that. You can get stop techs for $1750. '99 Mazdas for probably $1k.


But first, i'd figure out whats up with you stock brakes. Bad rebuild? Bad pads? Bad technique? Old rotors? Something aint right.

THEN, IF everything is truly hosed, pop for the ST's or 99 Mazda, and don't waist your time.

Brackets for both calipers are about $180. Calipers are about $500. And rotors I still dont know where to get a decent set in Europe.

I dont think I would track M3 much, but on the other hand, the one I am looking at holds the track record. Its 2002 with 47k miles. SMG tranny.

I'm still not decided what to do.

Ptrhahn, I have to admit you are right, custom kit would in the end cost too much time and money.

As for my calipers. I had them rebuilt 500miles ago and after 2 track sessions, the pistons are sticking again. As if someone is constantly pushing the brakes. I guess the mechanic did a lousy job. But on the other hand its worth mentioning that the car sat for 2months now and could that be causing sticking ? Anyway, I need to have them taken apart and cleaned I guess. Other problem must be the pads. I just hate it how they feel on the track. No initial bite, have to push on the pedal like a maniac and still I'm not sure if I will slow down enough for corner entry. Very unsettling when going for the fastest lap.

I guess I will give my stock brakes another shot, resurface the rotors, rebuild the calipers and get some NTech lapping days pads. If that doesnt work out, I'll step up with what you suggested - 99spec brakes or stoptech (or similar if a good deal pops out in the for sale section).

What do you mean with crappy pads leaving deposits on the rotors ? Because I took a look at the front rotors after the sessions and their surface was really looking uneven, but I though that was rotor wear. Hmm...

What pads are you using now?

Of note- Stoptech 13" BBK requires 18" rims. AP 13" BBK has calipers that accept a 17" rim.... Also '99 RZ front brakes are another option...

I love my 13" AP's... zero brake fade on the NorCal road courses and they aren't even ducted. I run Alcon rotors just like the Indy cars use ;)

Stop Tech's only require 17" rims.

A local company makes them and advertises them as agressive track pads.
I only have experiece with Bönez Stage I front pads and these, so I cant really compare much, but obviously they both suck at the track.

What influences the initial bite and how the FD brakes feel ? Because I never liked the FD brakes much. Hopefully its the pads.

Pad do... Some have a harsher initial bit, some don't.

Since the pad you were using is some sort of custom pad over there, I can't comment on how good or bad it was. As you know, a lot of us state-side use and love the N-Tech pads. They may be worth the cost getting them over there if you are really serious about continuing to track your car.

How is the initial bite with NTech's ? Can you lock your wheels/engage ABS at say 100mph (on DOT tyres) ?

Here's the description of the Lapping Day pads: