I'm wondering if there's a way to upgrade from single piston rear calipers to 2 pistons or 4 pistons? Does anyone make such a kit or can we use the FD/FC front calipers? Would we even be able to retain the emergency brake?

 

you dont want the front calipers on the rear

 

Such an upgrade would be a horrible waste of time/energy and resources.
Rear brakes provide only a (relatively) small fraction of the car's total braking power and you'll be hard pressed to get the proper balance, not to mention the difficulty of retaining any ebrake capability.

I'm upgrading my fronts to 4-pistons but not even bothering with the rears...I'll keep the solid (non-Turbo) disks and calipers...cause I'm confident that it wouldn't make a noticable difference.
Even a moderately hard-driven street car shouldn't exceed the capabilities of the stock system.

 

right, but with a big 6 piston front brake kit, you'd want to install bigger rotors and calipers with more bite and more even wear, along with a brake bias proportioning valve to even out the braking and bring it back to 85/15 or 80/20 from 90/10 or 95/5 , right?

 

Are you racing this thing, determined to go total overkill or just curious?

 

I'm not going to lie, overkill is the primary reason, I mean who thinks of going with Endless 6-Pot Calipers in the front? If someone actually thinks that's normal, then he has some issues. However, I do go to autox's and track days and I'm afraid I'll just get a crapload of understeer on braking and I won't be able to do things like trail brake with a big upgraded front. I figure a proportioning valve might not be enough so I'd like to go with Corksport's rear rotor upgrade along with adapting the front 4-pot calipers for the back. You think this can be done and will it be possible to retain the emergency brake?

 

u dont need to upgrade the rears...

 

NO.


-Ted

 

you'd rather overload the front with bigger rotors? I feel that just upgrading the front will bring the fronts to lock too fast, and wear out the front tires faster. Then again, I've only auto'xed with stock brakes so I don't really have an idea with upgraded fronts only.

 

Forget the emergency brake...you're way beyond that (and don't even think of trying to use a line lock...).
You can also forget the idea that a proportioning valve will work, your plan demands a dual master cylinder setup with a proportioning bar.

You're concerns re: track days would be better addressed with suspension. tire and brake pad upgrades (assuming that all the brake components are already in tiptop condition) than what you propose.

Remember that real race cars run components like 6-pots because they have to...if they could get away with smaller, lighter ( and not trivially-cheaper) parts they'd love to.

You can, and should.

 

You're overthinking the whole thing.
The fronts do the majority of the braking - I think you already know that.
Yes, it's all about balance.

I run 12.19" with Wilwood Dynalite 4-pistons up front.
I have no problem with the stock rears.

Go talk to Tim Spencer tims about the 13.0" with Wilwood Superlite-6's, cause that's what he used to use on his Super Unlimited FC in NASA racing.
He has no problem running the stock rears.

The rears have more than enough power to stop the car - remember you're still only trying to slow down the chassis weight.

Stuffing 4-pistons back there is TOO MUCH brake which will get you into trouble.
You're basically adding a lot of weight and complexity in the rears, and then try and dial the bias back down just so you don't get oversteer issues under braking?
This is why it doesn't make any sense.
If you wanna be like FD owners who want to brag about about how big their brakes are, then go right ahead...


-Ted

 

ic.....i was afraid the rear wouldn't have enough bias with the stockers. I think the ridiculously expensive kit that I'm looking at uses 12.75". Since you're telling me they do, I guess I can junk that plan. I was also wondering about other options. I know the FD and FC front brakes are rather similar on many aspects. Do FD big brake kits have a chance in hell of fitting on FC's?

clokker, I'm going with revalved koni's with the gc coilover kit and yokohama advan neova's. I think that should be enough for tires and suspension so I was moving on to brakes. The one thing that I must have is that the car has to be streetable. I don't want to build an all-out race car just yet, so if any rear brake option takes out the e-brake, I'm not really interested.

 

Actually, the stock rears have more than enough clamping force.
The rear brakes either runs through a stock bias valve, or it's designed into the master cylinder.
If you pull out all of the stock bias, the rears lock up pretty damn fast.
If you want, you can bypass all of that and run your own manual bias valve to mess around with it.
If you need even more rear brake, you can always step up to more aggressive brakes pads for the rears.

No, it's a waste of money, since the hubs are different.
You're basically paying for the custom adapter from the hub to the brake caliper.
Most aftermarket brake kits use universal brake calipers or something stolen from an OEM application.
If you can make the custom adapter yourself, you can basically slap on almost any brake (caliper) you want...


-Ted

 

well the vented turbo rotors might we worthwhile. Dissipating heat is a good thing.

The stock rotors can't take really hard abuse. My stock rotors on my GTU overheated and warped after 3 straight runs at Deal's Gap. They were pouring smoke out and ended up warping.

 

You can put better calipers on the rear, the heavy stock cast iron single piston sliding calipers are a cost-saving measure. This design belongs on an economy car.

BUT, you need to keep the piston volume the same (or nearly so) to maintain front to rear braking balance. ie: you need a four piston caliper that has the same total piston volume as the single piston you are replacing, so you'll need a four piston with really small pistons (or a two piston with no-so small pistons). This is to keep the stock master cylinder.

OR, you upsize both front and rear by the same % and install a bigger master. I would stay away from proportioning valves that bleed off pressure as a way to ballance brake systems, makes for a softer pedal.