edge04

This may be a silly questions but as my 3rd grade teacher said...."no question is.........

Any issue with running mixed brand brakes from front to back? I have a 06 Z51 and currently own and ready to install rear Brembo calipers and rotors. I haven't bought fronts yet, was hoping to find fronts used for a good price but no luck so far. I can bite the bullet and buy new but I do see great deals on used and new Wilwoods, AP, Stopetech, etc.

So any known issues aside from cost? Thanks

el es tu

The car will look a bit odd, but the bias should be fine if youre running a corvette specific kit and similar pad compound.

edge04

Trust me, I am worried about the odd look lol

flash911

Edge - verify front and rear piston area of the new and old calipers. If they're the same or similar percent to total front and rear you should be good. If not, you'll have more bias on one end.

ErnieN85

C6 has proportional control by the ABS so no problems there

flash911

Shows you what I know, lol. Does the C5Z have proportional control as well?

ErnieN85

no it does not

JRitt@essex

As long as the rear Brembo kit you have was designed to mimic the OEM rear brake torque output on your car, you should be able to install an aftermarket front kit that was designed to mimic front OEM torque output. That's the big question.

We have a killer six piston front AP Racing kit that would probably work well. I'm getting ready to blow these out because I'm overstocked with them. I think you'll be pleasantly surprised by the price at which you can get them. If you're interested, I can help you figure out if they're compatible with what you have. Shoot me an email.

These come in black or red, six piston, 362mmx32mm disc, fits inside many 18" wheels.

AP Racing Factory BBK for Corvette





[IMG]https://cimg4.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/1072x711/80-cp9040_1_1_1_1_7d43193b6548d8858

99525df7f116f61efeddd1c.jpg[/IMG]

96CollectorSport

So how does this "proportional control" work? Does that mean you can put any brake kit you want on the car (front or rear) and the ABS will figure it out?

ErnieN85

with in limits yes. it modulates the pressure to the rear brakes.
to balance the braking. in the older corvettes there was a proportioning spring you could change to change the balance now it's done by the ABS

96CollectorSport

Ernie,
Not to come off as a jerk but that question was kind of a trap. The "proportional control" you are talking about is actually called Dynamic Rear Proportioning (DRP) it is designed to change rear brake bias for a given situation (braking force applied, yaw, speed, g's etc) - there is a tolerance there but it has it's limits. The system is designed to work with stock components and stock tire sizes.
If you change brake piston sizes / rotor diameters within 10% or so you will be fine but then I would make sure you are running tire diameters darn close to stock.
If you are running square tires front & rear and messing with piston sizes etc you may run into troubles.

Also the later C5's (01-04) did have DRP it's only the 97-00 cars that did not.

When these systems work it's great, but when they have issues it's he!!, again not trying to be a jerk just want the most accurate info possible out there.

edge04

so what do people do when running different tire sizes or rotors, etc?

Bill Dearborn

Although the ABS should keep the rear wheels from locking the change in physical bias could cause some control problems under heavy braking.

Bill

ErnieN85

hey it is ok.... i couldn't remember the exact name and you'll note i did say within limits. I just not sure what those limits are and so wouldn't want to say any given setup would work (right).

edge04

any answers?

JRitt@essex

Many people run sub-optimal brakes! Seriously, that's the answer. A lot of people blindly throw brake components at the car assuming everything is compatible. They assume that because the brakes are from a reputable manufacturer, then they'll surely "work." That's like taking a component from an Apple computer, installing it in an Acer, and assuming that you won't get a blue screen of death when you boot it.

As others have mentioned, a properly designed brake system has carefully chosen components to keep everything working in harmony. All of the software programming (ABS, EBD, TCS, yaw control, etc.) is built around the OEM hard parts and your inputs. The car's 'brain' essentially makes decisions based on the input it receives from the hard components combined with all of the sensors and your foot. A huge number of calculations are being completed every second, and the car reacts accordingly.

There is a range of readings that can come from the hard parts, because the conditions the car will experience will not always be the same. For example, the ABS system will react differently if it encounters ice vs. gravel vs. concrete. Why? Because a tire reacts differently to all of those surfaces, and loses grip at a different rate. Also, each wheel on a modern car has an independent sensor. The left front tire may be sliding on ice while the right front tire is on asphalt. The car then has to figure out what you're trying to do when you step on the brake pedal. Did you gently ease into the brakes, or did you stand on them? How many times per second is the tire spinning vs. the speed you are traveling? Is a wheel locked up? That tells the computer what surface you're probably on. The car reacts accordingly. As these systems become more sophisticated, the probability of the car making the proper educated guess increases. The world is an imperfect place however.

So if you go outside of the acceptable range built into the car, you're essentially feeding bad data to the car when it's performing the above calculations. For example, if you change your overall tire diameter drastically, the car will see the "wrong" number of revolutions per second. With that bad data, every calculation downstream is therfore doomed to be incorrect. The programming will cause the car to react a certain way, but the results might not be appropriate given the actual conditions being encountered. It's a classic garbage-in, garbage-out scenario.

You do not want to rely on calculations and electronics to ensure that you have proper brake bias and your vehicle is braking most efficiently. What if you're running larger than factory rear brakes (larger rear discs or pistons than stock, creating more rear brake torque output) and your ABS, EBD, etc. fail? Will your rear brakes lock up before the fronts, sending you into a spin?

As mentioned at the beginning of my post, sub-optimal can mean a number of things. You may not have a catastrophic failure, but you can have a long brake pedal, inconsistent ABS intervention, etc. You may also be leaving some stopping distance on the table. Rather than your car stopping in 105 feet from 60mph, you're bumped up to 113 feet. Some people move forward with brake mods that put them in that position, but they don't realize it. The most common scenario is that they put on a front brake kit with stiffer calipers and high mu pads...except the pistons are bigger than ideal and it has far too much front brake torque. The pedal feels hard and has good bite because of the stiffer calipers and aggressive pads, but the rear brakes aren't doing their optimum share of the work, they're wasting rear tire grip, and actually lengthening their stopping distances. Since it feels good, they think they've moved forward, when in reality the car is actually under-performing.

Your goal when selecting components from different manufacturers should be to ensure the brake torque output on each end of the car is very close to OEM. That is accomplished by looking at the disc diameter and the piston sizing of the new potential components (holding pad mu as a constant). In that manner brake torque can be calculated, and that will tell you if the components will integrate seamlessly with your car, or if they'll confuse the heck out of your car's 'brain.'