[lcplpunk]

Howdy all,

I am wondering how increasing the size of your rotors in addition to increasing the rim size, weight/tire size/weight will increase braking power. Is the difference in rotor size really enough to offset the additional weight?

 

[ilh]

QUOTE (LCPLPunk @ May 28 2010, 11:21 PM) index.php?act=findpost&pid=807580

Howdy all,

I am wondering how increasing the size of your rotors in addition to increasing the rim size, weight/tire size/weight will increase braking power. Is the difference in rotor size really enough to offset the additional weight?[/b]

Ever take physics? It's all in the lever-arm that the caliper has to provide stopping force. The larger the diameter of the rotor, the more distance the outside perimeter travels in a rotation, thus the caliper covers more area and is able to reduce velocity much quicker.

A bigger rotor wouldn't really add all that much weight in the grand scheme of what you get in return. The most common mod for 2000's like mine is to upgrade the 10.9" rotors to the 11.6" found on newer models. This is a very easy mod which is effective in both cost and dissipating heat.

So in a word? Yes! Too much braking power is rarely a bad thing.

 

[lcplpunk]

Never did take physics, some day I might though.

I figured the larger rotor wouldn't add much more weight, but since I have 15" rims/tires and the larger rotors require 16" rims/tires, I would add additional weight there. I figure if the 16" rim weighs 2 more pounds and the tire adds the same, I would be adding 4 pounds per wheel/tire combo. This is the weight that I would be concerned with.

 

[nbpt100]

QUOTE (LCPLPunk @ May 29 2010, 02:52 AM) index.php?act=findpost&pid=807592

Never did take physics, some day I might though.

I figured the larger rotor wouldn't add much more weight, but since I have 15" rims/tires and the larger rotors require 16" rims/tires, I would add additional weight there. I figure if the 16" rim weighs 2 more pounds and the tire adds the same, I would be adding 4 pounds per wheel/tire combo. This is the weight that I would be concerned with.[/b]

Not to get to techie but the physics of it comes down to rotational inertia. It is a function of the radius squared and the mass of what ever is rotating. As you increase either of these features the energy needed to change its rotating speed is greater.

Adding a bigger wheel and rotor will required more energy to stop and to accelerate. Since the radius is squared it is more sensitive to changes.

As explained very well by ILH you get more breaking power and better heat dissipation with the 11.6" disk set up. I am sure this is why the Ford engineers upgraded the brakes a year after upgrading to 16 wheels.

Your brakes will wear out faster if you only upgrade the wheels to 16".

 

[egiroux]

In an ideal world the largest brakes that will fit inside the rim should be used. The extra weight is negligible compared to the weight of the car. Cost is the primary reason to go smaller. Un-sprung weight does affect handling, but this is more applicable to performance cars.

 

[kevinspann]

QUOTE (LCPLPunk @ May 29 2010, 03:52 AM) index.php?act=findpost&pid=807592

I figure if the 16" rim weighs 2 more pounds and the tire adds the same, I would be adding 4 pounds per wheel/tire combo.[/b]

Pretty much all of the weight you would add would come from the larger wheel. If you think about it, there is actually a little less tire, since the sidewall would be shorter. But to counter that, some tires are lighter than others.

All of this is also taking into account the assumption that the 15" wheel and tire combo weighs less than the 16" wheel and tire combo. This may not always be the case.