why aren't the rotors matched front and back. my rear rotors are noticibly smaller on the rear as compared to the fronts. I don't have the z51 but rather the mn6 coupe. i think it would look much better if they were matched but i'm just trying to find out why they aren't. don't wanna replace the rears with larger ones only to find out there was a reason for the different sizes.

 

There is a good reason. When you apply your brakes most of the stress is on the front wheel brakes due to the shift of weight resulting from the car's forward momentum. Therefore, the front discs must have a larger sweep area to bring the car to a quick stop. The rear discs consequently do not need to be as large.

 

understood, but visually they don't look as good.

since we are on the subject why can't the rear brakes be set to grab harder and cause the car do drop down in the back and let the front rise a tad. kinda like dropping an anchor (picture a jet landing - rear down first then nose). i understand centrfigal force and momentum places a huge part but why couldn't it be made to drop the rear, grab the brakes, raise the front a tad and brake all at the same time ?

 

TRR

 

the immutable laws of physics.

 

 

I almost can't bear to see what kind of answers this is going to bring. Just too painful to watch

 

Maybe you could add a 3000 pound weight right above the rear spoiler of your Vette so the rear wheels will grab more!

 

I think the holes in the rotors looks cool, I want to drill some in mine using my cordless drill, does anyone know what size drill I should use? I figure I won't even have to take the wheels off. Let me know!

 

that is impossible

 

Wait, go back...did you say something about an anchor?

THAT just might do it.

 

<silent drum roll....>

It is possible to adjust the suspension pick up points such that the rear of the car goes down under braking and goes up under application of power. However, this will cause lots of bad things to happen suspension wise--that I don't have time to go into here.....

<end of drum roll...>

So, lets go back to you first leadin to that question: Why can't you make the rear brakes do more of the work? After all, the rear tires are bigger than the fronts! Well it turns out that you could if there were enough weight biased towards the rear end of the car (like Porsches or Ferrari mid engine cars).

But the whole issue starts out with a false premis: Why can't the rear brakes grab harder? Lets examine what happens if the rear brakes lock up first! front end has traction causing a force vector of deceleration between the front axel. Rear brakes have locked up causing a smaller foce vector on the rear axel. Therefore the fonts have a large decelerating force and the rears a smaller force. Therefore the front of the car want to decelerate at a faster rate than the rears. When this happens the car wants to be orrented in the 'other direction' e.g. spin! So, the braking systems are always designed such that the front brakes reach impending lock before the rears to give the driver stability under braking.

Conversely, when the fronts lock but the rears continue to apply braking forces, the car goes straight (but is not steerable).

 

thanks, maybe grab harder was the wrong terms to use but you saw the point anyway.

with all this being said, would there be a problem with larger (same size as the fronts) on the rear ?

 

Baer Brakes makes a 14" for the rear:

 

I remember a recent "shootout" in one of the muscle car magazines. All of the cars that had added mombo rear disc brakes had problems with swapping ends on high speed braking. The car that did the best was one that added the larger than OEM drum brakes on the rear and aftermarket disc brakes on the front. The moral of the story is that if you make your rear brakes as big as your front brakes, you will have to get an adjustable proportioning valve and back off the rears. Kind of defeats the purpose.

Sometimes too much bling is a bad thing.

 

I think you're on to something here. I think hand drilling would be too labor intensive. I would try teflon coated bullets. 30 caliber would be the proper diameter.

 

When you shoot the holes in the rotors, is it advisable to remove the rotors from the vehicle, or can I do it with the rotors still attached. If it matters, I do have a good aim.

I bet after piercing the rotor the speed of the bullet will be so slow and just drop out the other side nice and gentle.

 

Yeah I just did this last weekend. I put a phone book behind the brake assembly though to catch the bullet. Worked like a charm - even mounted the bullet in a frame and hung it on my garage wall shrine.

Actually though I just used a .22 hard point - the force of impact opens the holes up a little anyways.

If only I had a dollar for every minute complaint - I could buy those Baer rotors...

 

The car is already balanced and braking forces are adjusted so that all 4 wheels will be impending lockup at approximately the same time. If you change anything, you will upset this calibration between front and rear. The rear brakes will require much less braking power to lockup because of the drastically reduced weight on the rear when under hard braking. THIS is due to the fact that the center of gravity is above the axle height and the high CG will be thrown forward, lifting the rear and compressing the front. Having a rear engine/rear weight bias, will help put additional braking capability on the rear but will still be less than the front as long as the center of gravity is above the axle.

Physics can't be changed by putting larger rotor on the rear.

 

i'm not looking for any better braking just a balanced look front and rear. i was curious if i used the same size for both front and rear if i would be inviting problems.