Rear Caliper Position - Any Advantages?

[dontlifttoshift]

Good point James. When you say leading/trailing are talking about the caliper design itself or just differential bore pistons and their location.

I think suspension link location and arrangement would have to be determined before you could determine how the caliper would load/unload a tire.

[Bryce]

I will draw a free body diagram. The frictional force went somewhere, grab a spinning bike tire where does your hand go...

I thnk its going to endup being a force on the tire, either up or down. I dont think it would increase/decrease antidive.

[dontlifttoshift]

Originally Posted by Bryce

I will draw a free body diagram. The frictional force went somewhere, grab a spinning bike tire where does your hand go...

The emergency room........

Rear mounted caliper will load the axle then, in the direction that the tire is rotating. So will a front mounted caliper. In the case of a torque arm type setup with the outboard links mounted vertically at axle centerline, for example, the rear mounted caliper would load the tire and front mounted would unload it......in theory. I'm curious about this.

[realcoray]

I'd suggest looking at where OEMs or competition racing cars put their brakes. The assumption is that those people spend millions of dollars looking at these sorts of questions.

For the C6R and Stingray for example, GM has the brakes in front. On F1 cars though it appears like they are very low in the back.

Some of these things may be packaging issues, the F1 car for example has a lot stuff going on around the caliper, but you have to assume that their goal is to maximize everything to reach peak performance with their very light weight, high horsepower cars. Shifting of grams lower means more to them than it does on a production corvette or even for the C6R.

Again, it's pretty much not going to make any difference, but this is the approach that I will often take when considering something like this.

[Sieg]

Koenigsegg Agera R rear calipers are at 3 & 9 o'clock behind the axle. Their engineering is probably some of the more current and advanced.

Porche's Carrara GT had the rear calipers slightly lower than 3 & 9 o'clock in front of the axle.

Then you'll see some F1 cars with bottom mounted calipers.



What is best and how much influence does it have relative to the desired performance objective?

[intocarss]

Here's some discussion about it

http://fsae.com/eve/forums/a/tpc/f/1.../m/80310023931

[dontlifttoshift]

Good Link!!

[sik68]

I would venture to guess that caliper position on high end cars like F1 is mostly dictated by efficient airflow in that area for brake cooling.

I agree that caliper position affects the wheel bearing loads during braking, but not the resulting load on the tire.

If caliper position did change the load on the tire, then under hard braking the tire could go into an "open feedback loop" and your car would a) become infinitely heavy and crush through the earth (3oclock), b) speed up (6oclock), c) levitate off the ground (9oclock), or d) instantly stop (12oclock) just by pushing harder and harder on the brake pedal. :p Just exaggerating for visualization purposes.

[ironworks]

I hope there is no issues because I just put a floater in my dirt racer and had to stagger the calipers to keep my track width the same in the rear and keep my stock staggered shock mount positions. So one caliper is forward one one is backward on the other side. The opposite of the shocks.

But its not like the brakes are really only used to park the car in the pits. HAHA

[intocarss]

Originally Posted by ironworks

I hope there is no issues because I just put a floater in my dirt racer and had to stagger the calipers to keep my track width the same in the rear and keep my stock staggered shock mount positions. So one caliper is forward one one is backward on the other side. The opposite of the shocks.

But its not like the brakes are really only used to park the car in the pits. HAHA

Are you testing at Bako on Sat?