Which big brake kits retain the rear parking brake?
 

Hello,

I've been trying to decide which direction to go with my big brake upgrade. I have a car that will be mostly driven on the street, but will also do track events. I've got about 400 RWHP and am running 18x10 with Pilot Sport cups. But I want to keep the emergency brake for road use.

I had been considering the Stoptech/RZ combo, but I'm bummed at two issues caused by the RZ rear setup:

1) There isn't a big selection of pads
2) Changing the pads for track use is a PITA

So I'd be okay with either a more common rear brake caliper (with fixed pistons and a big pad selection) and a spot caliper, or something that's integrated. The only example of the latter that I've seen is at SR Motorsports:

http://www.shaneracing.com/sr93susp.html

The front kit looks like a Stoptech that they've spray painted, but the rear kit is interesting...a 4-pot caliper that retains the emergency brake?

But anyway, I'm wondering if anyone else has seen a good setup that provides upgraded rear braking with easy access, good pad selection, and e-brake retention.

Thanks,

-ch

i've also wondered the same thing so im bumping for the both of us! i need that ebrake...

Have you tried just running good street pads at the rear on the track? Few of us really need track pads at the rear, especially with bigger rear brakes.

I haven't tried that, but it sounds like a setup like that (13" fronts with race pads, RZ rears with street pads) would have a pretty heavy front bias. Stable, but would give up a lot of braking potential.

-ch

You might take a look at this thread:

https://www.rx7club.com/suspension-wheels-tires-brakes-20/n-tech-competition-compound-440657/

Quite a few people using a street pad on the rear...

The RZ rear brake pads aren't hard to change. They're just like the stock setup. All you have to do is detach the parking brake cable and undo one bolt. Easy.

There is a fair amount of stuff available for the RZ rears since it's the exact same pad as the stock rear brakes. I've used the porterfield R4 pads in the rear with good results.

See Mahjik's response, but also, the thing to consider is many mild track pads (like the Ntech Lapping Days) don't really have a higher coefficient of friction than an aggressive street pad.

I would call SRX7 to clarify the exact specs of the rear kit; I've got a sneaky suspicion that the 'stock photo' for the 'Mazdaspeed' rear kit is simply the front BBK made into a thumbnail - and that the rear kit they are selling is simply the RZ/RS kit. Because it is technically available from Mazdamotorsports (nee Mazdaspeed USA) it *is* a Mazdaspeed product, and everything in the description matches the RZ/RS kit. There is no mention of how many pistons, two-piece rotors, etc....

I wouldnt be surprise if that was the case at all. over the years I have learned to be skeptical of that place.....

I guess the issue is whether you can run 'lapping day' pads on the street. My experience has been that anything that can stand up to a full track day are not streetable. And by that I mean squeaking, poor bite when cold, and dust that's really hard to clean off. On the flip side, street pads will give out if you're hauling the car down from 80MPH+ every 15 seconds.

That said, I haven't tried the N-tech pads. But the thing that kills me about the stock rear caliper is the fact that you have to screw the piston in as soon as you get any appreciable wear. I've taken 20-30% out of race pads in a single track day, so if I'm swapping pads it gets to be a real pain.

But the sense I'm getting here is that people are running a 13" BBK (Stoptech, etc.) and RZ rears, both with street/strip pads of the same compound, a-la N-Tech. Is that right?

I'm calling SRM tomorrow and I'll post my findings here.

-ch

Check out the thread Mahjik linked. Ptrhahn runs the Lapping Day pads up front with Stoptechs, Axxiss pads at the rear with RZ/RS. I will be running this as well.

Hmm. I did something similar on my MR2 turbo, but it's not a great solution IMHO. The whole point of buying a kit like Stoptech that's biased to match the RZ rears is so that you retain the balance. When you run a hotter pad in the front you push that bias forward. You also get different behavior as you warm up the system.

I gather that Ptrhahn is a quick driver. What I'm not sure of is whether that setup make sense. Cars with a front bias feel really stable and predictable, but give up performance and reduce the effectiveness of trail braking.

Not trying to argue. Just want to make the right decision. And I appreciate the info and perspectives.

Let's say I wanted to go with the RS/RZ setup and wanted modular rotor/hats in the rear. Where's the best source for this either as a kit or parts?

Thanks again,

-ch

No, this is a good discussion. :) I'm a little worried about the same thing. However, there's only so much you can do given the constraints. If you are really concerned about front/rear bias, I would talk to Dave Zeckhausen of Zeckhausen Racing. He is very familiar with racing FDs and is the biggest Stoptech dealer.

The only rear brake kit that I know of that actually uses a different caliper design is the Brembo kit that Ntech sells. It costs $2000+ just for the rears....

http://www.ntechengineering.com/imageslarge/nt00143.jpg

Wheee!

Nothing like a 4-wheel kit for $6K!

I'll talk to David as well. I'm wondering if anyone has done a kit with a 2 or 4-pot fixed caliper and a mechanical spot caliper that works with the factory e-brake?

-ch

There's alot of good info in this thread.

I'll shortly be installing the Mandeville BBK with 13" coleman rotors and widened stock calipers.....am I throwing off the bias much with this setup (stock rears, ebc yellow all around)? I read on rob robinette's site that he had to adjust his system a bit with a brake proportiong valve. Not too familar with these things.

Tyler, comments?

Rich

Rich, your balance will only slightly be affected, since the Mandeville uses the stock caliper. The only increase in braking force will be due to the increased leverage.

Nothing that can't be balanced out by installing the 99 rear brakes....:stickpoke:

1) Spoke with Nick at N-Tech Engineering. He was very helpful and provided quite a bit of information. He does not recommend the Axxis pad on the rear for racing. He feels that if the pad isn't going away rapidly, you're probably not pushing hard enough. He said that his Comp pads would be recommended F/R, or the lapping pads as well. He also said he sells a $20 tool that makes the piston rotation in the rear much easier.

2) Spoke with SRM. Their kit is indeed a floating single-pot caliper, A.K.A. the RS/RZ caliper.

3) Haven't gotten a hold of Zeckhausen yet to hear his perspective.

I still haven't found any fixed rear that retains the e-brake. I spoke to Stoptech and they said that such a caliper isn't made--that OEMs uses drum/shoe combinations in the rear of most modern sports cars. (My STi does this.) So if your car originally had a mechanical caliper, you'll almost definitely need a secondary spot caliper in concert with a fixed-pistion primary caliper.

So now I'm seriously leaning towards the RS/RZ setup. Can someone help me find a good price for this? I called Precision Brakes and they are getting me a price. (FWIW, they make a Wilwood 4-wheel kit with a mechanical spot caliper, but I won't run with that particular brand.)

What's the best place to get the RS/RZ calipers? I'm not a Mazdacomp member, and their website has been down for weeks anyway.

Thanks,

-ch

Jason at the RX7store often has them in stock.

Did they mention anything about a rear kit they listed in their previous product sheet, that supposedly used a drum style parking brake setup, and which required mod to the spindle assembly? Always wanted to ask about that, but never got around to it.

The new price list speaks of only the rear kit with the parking spot caliper (pg 26) that you were refering too:

http://precisionbrakes.com/newnewlist.pdf

You could speak to them about making brackets to adapt another brand caliper for the current listed kit, but I wouldn't count on it happening quickly.

I'm going to talk to them tomorrow to get a price on the modular rotor/hat for the 99-spec caliper, so I'll ask this question. I worked on a Wilwood 6-pot/4-pot kit for a friend's 240Z, but I was surprised at how little material was used in the caliper bodies. The consensus seemed to be that Wilwood was aimed primarily at the oval circuit where braking power is not key, but weight is. Also, consider this comparison done by Stoptech. I'll give you one guess who the 'W' company is:

http://www.stoptech.com/products/BBK...calipers.shtml

They also lack dust boots/seals which is a bummer for street use.

That said, I'm not trashing anyone using those products. But I think they are designed for a certain type of racing, and they don't fit my overall philosophy for the car I'm building.

-ch

This might not be able to work with the 7. But I have installed stoptech's big brake kit on a 350z. It retains the stock emergency/parking brake, wich is a small drum style in the center of the hat. Is there a way to adapt this type to the 7?

Another idea that I have had was to make a small disc bake system that sat just in front of the diff on the drive shaft. I think this is used in rally, but not shure. The main problem with this idea is that the 7 has the PPF in the way.

The last option that I can come up with for a parking brake would be a line lock for the front brakes, wich could serve duel purposes.

If you're interested in some serious brakes, w/ custom work to your specs (including retaining your e-brake), I'd suggest you contact Frank May of Pocket Rocket Racing in Canada (fmay@superaje.com). Tell him Ramy sent you.

To give you an idea of what he's capable of, here's a set of full carbon-on-carbon brakes he custom made for a friend of mine in Australia... You don't want to know the price lol, but it was the perfect final touch for his SP Bathurst FD :D

https://www.rx7club.com/attachment.p...d=175235&stc=1

Interested in a used setup? Cuz I have one I'll be putting up for sale very soon...

~Ramy

Holy crap. That definitely takes the award as the most insane FD kit I've ever seen.

Actually, I am curious what that kit cost. My guess is:

* Calipers: $3K ea. for the fronts, $2K ea. for the rears ($10K)
* Rotors: $1K ea ($4K)
* Hats and brackets: $2K for materials and design time

So, maybe about $16K?

I am interested in your RS/RZ setup. Can you PM me some details? What are you replacing it with? (Don't tell me it's the C/C setup above?!?)

-ch

And it still doesn't have a parking brake ;)

FWIW: my 99RZ rears w/2 piece precision rotors
http://www.negative-camber.org/crispyrx7/rearbrake.htm

I run these with an AP racing front BBK and PF 01 front and 99 rear compound pads on the track. Brake bias is still just a tad front heavy but much more manageable than with the stock rear brakes. Trailbraking is still quite do-able.

HTH,
Crispy

Yea that's what I thought ;) But it's only fitting, seeing how Mazda extensively used CF throughout the SP Bathurst FD for weight savings...

You're close. The rotors ran a bit more, and only b/c they're some very expensive material (the same actual material used in F1 cars, not the PCCB crap that Porsche had a disaster with), and they're sold in a minimum quantity, so you end up buying more than you need. I'm sure Frank will discuss the details further w/ ya if you'd like...I can't remember too much, as this was over a year ago.

On that note, however, b/c these are the full carbon setups, they perform just like the F1 brakes as well - poor cold braking characteristics and when warm, they stop so hard you end up locking up your tires 24/7. There's really no modulation at all. You'll need to run R Compounds. They're basically unstreetable. I even spoke w/ Chuck Mallett of Mallett Cars about this (http://www.mallettcars.com/), b/c he's the only one to ever use a full carbon-carbon setup on a streetcar (some crazy hp Vette), and he basically told me the same...given how light the FD is, unless you're running R compounds, they're completely unstreetable.

I haven't decided what kit I'm going w/ yet. I have a few ideas up my sleeve :D Drop me a PM in 2 weeks (which is when I'll be home) and we can go from there. Sound good?

Crispy, Frank actually ended up modifying the rears to work w/ the stock FD parking brake. The guy is insane. He takes your wheels (you send them to him, or take exact measurements), and he can design the largest and most powerful braking system given your size constrains, AND make it work w/ the stock parking brake :) Needless to say, however, you gotta pay to play... :)

~Ramy