As title really.

My FC came to me with FD front brakes fitted, which I understand involves a custom caliper mount etc, but it has stock rears- Is fitting FD brakes to the rear easy?

I wasnt really planning on fitting stock FD brakes to the back, but an aftermarket big brake kit, along with a big front brake kit (intended for the FC, of course).

Has anyone any info on that?

Thanks

 

I believe the rears are the same for the FD? The front brakes are the same with a spacer to accept a wider disk I believe.

 

Here you go.
http://www.corksport.com/corksport-r...grade-kit.html

 

Can anyone confirm? As that would be great news

 

FD has much larger rear rotors. The corksport link is a bracket to install the FC caliper over the larger FD rotor (I'm 99.9% sure thats what they use. It may be something different though)

But absolutely, the stock FD rear brakes are different and larger then the FC's.

 

the rotors are bigger. supernow sells caliper spacers that allow the use of the bigger stock fd rotors. orrrr, you can just use the corksport kit.

 

Ah, looks like my original post was reversed as far as the spacer goes.

 

Ah crap, basically I was hoping a rear big brake kit intended for an FD would fit, but by the looks of it no chance.

The corksport kit is interesting though, cheers for the link

 

The followup question would be, do you actually need bigger rear rotors? The answer is probably no, if the car is not tracked, because in most driving, the rears don't do much anyway - that's why the turbo/gxl/gtu/sport brake upgrade on na's just added a vented rear rotor of the same diameter as the base car, with the same caliper. The venting just improves rear brake cooling for repeated use, but doesn't actually increase rear braking torque.

If the car is tracked, the answer is maybe. If your rears are overheating after a race/lapping session, but the fronts are not, bigger rear brakes would be justified. If your fronts are locking up prematurely relative to the rears, you might also benefit from bigger rear rotors off an FD, using the appropriate caliper adapter - although you could try going to a more aggressive rear pad first.

FWIW, I find at the track my fronts will overheat long before the rears (actually, I've never overheated the fronts, but they definitely get WAY hotter after a long lapping session), and my rears will lock before the fronts, so in my case, I need more front relative to the rear - either via a larger front rotor (the FD conversion), or more aggressive front pads (which I'm already doing.

 

The caliper for the vented rear and non vented rear is different.

 

Correct, I oversimplifed, but the only difference in practical terms is the width of the caliper, to accomodate the wider vented rotor. The caliper is still single piston of the same size, mounted in the same location relative to the hub and rotor, so it exerts the same braking torque.

 

You are right about that.

 

Were do you get you info? By putting a corksport bracket and the 12.25 rotor will help keep the bias close to stock.
Here is alittle write up on big brake kit by Joel payne( frijolee ). https://www.rx7club.com/showthread.php?t=739122 . Also another good book to read is by an author name James walker jr. It is called High-Performance Brake Systems: Design, Selection, and Installation by Author James Walker, Jr.
http://www.teamscr.com/

Thanks Robert

 

^^ I'm not sure if you're suggesting I got something wrong, or are just asking for references.

The general rule would be that if you upgrade front brakes, you need to upgrade rears (proportionately) to maintain braking bias - which is easier said than done (the proportionate part). In practical terms, if you can lock the brakes (fronts and/or rears) under hard braking at high speeds, you don't need more braking torque, which is one of two major elements of what a "big brake" setup supplies. The fd conversion does this by using the bigger FD rotor and moving the caliper mounting outwards to accomodate that rotor, since you use the same calipers/pads, just on a larger diameter rotor. The braking force being generated at a point farther from the wheel hub increases braking torque through simply extending the effective leverage point of the brakes in applying force. Other conversions may also add larger calipers/pads that exert more force and or have a larger swept area.

The second element of a big brake conversion is more mass, so mass of the rotor can absorb (and re-radiate) more heat energy without becoming heat-soaked - in other words, exceeding a critical temperature - either of the pads, such that they are no longer effective, or of the brake fluid, leading to boiling, and the "oh $#!7" moment of stabbing the brakes and having the pedal go to the floor. So bigger brakes may be called for even if the existing brakes are able to lock the wheels at high speeds, if overheating in a racing or lapping situation is an issue.

My point was simply, based on my experience, more rear brake may not be needed, as on my car at least, the stock bias is excessively to the rear anyway, and of course, for street use, big brake conversions are pure style, since if the stock brakes are working correctly, tire grip, even with sticky street rubber, not braking torque, is the limiting factor in braking performance

 

It looks like fc3s91 is assuming you were saying that there was no difference between in braking torque between FC rear brakes vs adapting the FD brakes on with the spacer.

fc3s91, he is saying that there is no difference in braking torque from a rear FC non-vented rotor and a rear FC vented rotor.

 

I think it's not a problem, I believe it's very possible.

 

There are race and style suggestions that are well covered. It just comes down to what you're doing with the car.

As for big brake kits in the rear, they'll probably have multiple pistons and you'll open a whole new can of worms since the current master cylinder may not move enough fluid. Bias will be way off and replacement rotors and pads will probably be quite expensive compared to the stock FD hardware.

If I were in your shoes, I'd replace the rears with the corksport bracket and FD caliper to maintain bias. Although if you're set on upgrading your brakes, there is a writeup here about adapting EVO IX(?) brakes to the FC.

 

Yes, but the pistons are so huge that it would require at least the Corksport rear kit and would really only work well with a dual MC setup so that you can vary the bias more than a prop valve will give you (well, or a BBK with even more rear stopping power).