boxster rear calipers

[drewiee99 0]

hi does anyone know if a rear set of porsche boxster calipers can be retro fit to the front on to a corrado using 280mm calipers?

[PhatVR6 0]

I've got a set if you need any measurements.

[drewiee99 0]

would they fit behind original 15" g60 bbs rims

[2_Door_fun 0]

hi does anyone know if a rear set of porsche boxster calipers can be retro fit to the front on to a corrado using 280mm calipers?

 

I heard of doing that from somewhere. Would the rear calipers of said car be up to the front work of a Corrado?

[g60bv 0]

where is the handbrake mech.?

[drewiee99 0]

i think they run seperate little discs & calipers for the handbrake i looked up the size and they are 290mm i know they would fit behind 16" not sure on stanard wheels

[yalan 0]

Is it not a variation on the line lock which is used as the e-brake?

Porsche rear calipers certainly don't have a mechanical linkage.

 

I know the front calipers are used in the audi community quite alot as upgrade components. But most people suggest against using the rear calipers up fron because they've got such tiny pistons that it might adversely affect the bias.

 

Turns out that on the audi, the same vol of fluid moves pads the same amount on both the OEM 2 pot Girling G60s and the upgraded Porsche 4 pots. Switching to porsche rear calipers would severely upset this balance.

 

Having said that, there is / was a guy in the US who was offering Boxster rear calipers as an upgrade for the front. Guinea pig driver seemed happy on first report back.........

 

make of that what you will.

 

I'd say it is possible..... but without some serious calculations on the rest of the system I'd not just jump straight in.

[yalan 0]

from the guy who sold them in kit form in the US on the audi forum:

read more : http://www.s2forum.com/forum/showthread.php?t=9803

 

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Ok Ok this post got far enough! Time to clear some things up.

 

The kit is 309x20.6mm and does use the 996 rear calipers. To be honest, I was a little hesitant at first to produce the kit since the rotor is lighter than stock and the pistons are in the caliper are smaller than stock. However, I really wanted to test it out and put a nice kit under a 16" wheel. Remember that most of us in the states don't have 5 lug so the A8 rotors are out unless you want them redrilled, and thats not ideal.

 

So, the 12.2 wilwood rotors had an odd sized friction surface and the 996 rear caliper fit perfectly on top of it. I put it together and sent it to Marc to test out, not knowig what to expect besides a stiffer pedal. I was quite pleased to hear he likes the kit!

 

What has been mentioned - brake bias. OK I'm not 100% sure if the OEM prop valve will adjust for front-rear. However, my understanding is that it biases based on a pressure differential. The Bentley reinforces this. Ideally, ALL brake upgrades require fine tuning with an adjustable bais valve - doesn't matter if you are using 8 piston Brembos or 996 calipers atop A8 rotors. If you change calipers, bias does change. Marc reports it works well with no adjustment.

 

Rotor mass: I don't believe in the theory that a rotor needs to weigh 22 lbs to work. In fact, these extremely heavy rotors affect the car in every way - braking, handling, ride, fuel mileage, and acceleration. Start with a high quality rotor that can shed its heat quicky without warping. Wilwood is famous over here for their race-quality rotors. The Audi rotors can handle a ton of heat no doubt, but the heat produced by pad-rotor friction is concentrated at the face of the rotor and must conduct to the center in order to take advantage of the vented nature of the rotor. The temperature throughout the rotor is far from uniform and this contributes not only to rotor warping but pad glazing. By using a lightweight rotor with good cooling passages, heat is quickly dissipated through the vanes. Conside that cooling is affected by the following: temperature differential, materials used, and the ratio of mass to surface area. This rotor has virtually the same surface area as the 314x30 rotor but is less than half the mass.

 

In addition, these rotor rings are very inexpensive. Cheap enough you can carry spares to the track and change them in a few minutes. Try this: $40 each. You can't even buy stock rotors for this price.

 

Now, yes a lighter rotor will reach higher temperatures, regardless of the better cooling you experience. For this reason I recommend pads which are suited to high temp conditions. MetalMasters, R4S, DS2500, etc. Marc has had good results with his PBRs although I don't know what compound they are.

 

The calipers have smaller pistons - ok. They are still considerably stiffer and better at dissipating heat than the G60s. They also have larger pads and a better selection of compounds.

 

I'll admit, I wasn't 100% confident at first that the kit would be as good as it is. However, testing is showing that it is working great. I'd like Marc to continue testing it out as vigorously as he feels comfortable with so I can find out how it handles abuse.

 

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