Wilwood people

[Alex]

Have any of you guys thought of buying larger rotors (and corresponding hats)?

I'm jelous that the Brembo guys get 15'' front brakes, and have been considering buying the 14.5'' Wilwood superlite rotors. My logic is if you can fit 15'' rotors on the front with Brembos, and the 14.5s are for a C6 corvette, I think they should fit?

Of course 'thinking' is why I usually end up with dozens of spare parts that turn out not to fit :worried:

 

[Doc Kaler]

Oh, so that's why I have so many spare parts!

Tom,

Unless you intend to track your SL-C there is really no need to upgrade. The standard rotors have plenty of surface area for a 2400lb car for the usual brisk driving for which the car is intended. (Of course, I upgraded to the Brembos :thumbsup.

 

[marc]

Alex,
I am not an expert, however if you have the same swept area on the brake rotor, with a smaller rotor, with the same or less unsprung weight, why change. BTW the rotors that come with the kit are they .85" 1.25" or ??? The only reason I can see more brake rotor with all the same materials would be if you are going to save weight or generate shorter stops. the slightly larger rotor would be "argumently" capable of shorter stops. but what do I know?

 

[Alex]

My purpose would just be to have bigger, cooler looking rotors; nothing to do with stopping power.

Yes, I am such a poser :laugh:

(Of course, I upgraded to the Brembos :thumbsup.

//Wonders if this is a conspiracy by the 15'' rotors guys against us smaller rotor guys :stunned:

..........:idea:

:laugh:

 

[Howard Jones]

Lets think about this a little before we start assuming things. First, big brakes do not necessarily "stop the car faster or better". If the "smaller" setup will pull the car down at the limit of adhesion of the tires then that's all there is fokes.

On the other hand if the performance need is to slow the car REPEADLY for a relatively long period of time then the larger mass of the big brakes will be able to absorb the heat generated and then release enough of it before the next brake zone so that the rotor does not continue to soak up heat until failure. Sort of like a dam. Big rain, fill up, controlled release, then big rain again. No flooding These levels of brake heat generation will NEVER happen on a street car.

Big brakes really only stop the car more often not faster or better.

I have 12.18 X 1.25 HD vented rotors all the way around on my GTD and I have NOT been out-braked in an open track session yet nor have I ever experienced ANY over heating or brake fade in sessions that typically run for 20-30 Min's and on days with air temps as high as 105F.

I think that the standard SLC setup will be OK if used for 30 min open track sessions like I have been doing. If I do have a cooling issue then a LOT can be done to improve heat capacity with venting cool air to the rotors. I don't expect to have to "upgrade" the corvette brakes. Front 13X1.25 rear 12X.85. If I do it will be a result of the slicks and high down-force levels allowing much higher brake rates than I expect. Although the higher grip levels might just require less braking to get the lower laps times with the capibility of higher corner speeds.

We will learn more when I start running the car.

 

[Mesa]

Right on the money Howard.

 

[DBLDREW]

Lets think about this a little before we start assuming things. First, big brakes do not necessarily "stop the car faster or better". If the "smaller" setup will pull the car down at the limit of adhesion of the tires then that's all there is fokes.

Speed plays a big part though. Just for example purposes say the smaller brake set up has enough force to lock up the tires at say 50 mph (dry smooth surface, etc), any breaking you do above 50 mph and the larger brake set up will stop you faster, but it is true once you get to the tires adhesion threshold not much else you can do. It’s just bigger brakes will get you to that threshold faster, with means you are stopping faster.

 

[Eric]

It’s just bigger brakes will get you to that threshold faster, with means you are stopping faster.

The size of the rotor does not have any impact on the stopping power or the speed at which you stop. It is a complex interaction between the friction coefficient of the brake pad and rotor, the contact area of the friction material, and the force applied to the friction material. The size of the rotor is irrelevant in the stopping equation.

Howard is correct, the added mass of the larger rotor comes in to play on repeated brake application. Ever see those F1 guys running at night? That's why they run those big rotors.

Eric

 

[Roger]

I think people are forgetting that there is a lever ratio based on the diameter of the rotor. A large diameter rotor will require less pedal effort to reach the limit of tyre adhesion than a small diameter rotor. Smaller master cylinder diameters are the other way to reduce pedal effort but will have the disadvantage of longer pedal travel.
Most people will struggle to drive their car on the limit, but for those that do have the oportunatey they will appreciate the larger rotor.

 

[Wayne]

Hey guys, can we get back to Alex's original question? Will the Wilwood Superlite 14.5" rotors fit? He also stated "My purpose would just be to have bigger, cooler looking rotors; nothing to do with stopping power."

 

[Howard Jones]

Yes, they will fit. Anything can be made to work. It's all about the planning, thinking, engineering, and measuring..................and $$$$$$$$$$$$.

Really you can make adapters to mount the caliper of your choice and a custom hat to locate any size rotor if it will fit into the wheel.

Proper planning prevents piss poor performances. (Rodger Penske)

 

[Mesa]

Actually they won't fit. The caliper that comes with the kit is limited to the maximum dia of 14" according to Wilwood. My own investigation confirms the caliper have a maximum sweep of 14". Now if you want to take the caliper and stuff it on top of a larger dia rotor than recommended, some part of the brake pad will not ride on the rotor.

 

[EGLITOM]

Howard is correct, the added mass of the larger rotor comes in to play on repeated brake application. Ever see those F1 guys running at night? That's why they run those big rotors.

Eric

I´m not following F1 to deep in the last years ( to much restriction and rules). but aren´t they still have to run 13" wheels, so the rotors can´t be that big or ?

TOM

 

[Doc Kaler]

Maybe a better analogy would be the GT classes.

 

[Randy V]

You can machine out part of the bridge of the caliper to get it to sit lower down on the rotor. However, you'll find yourself also machining the mount in order to make that adjustment as well..

Larger rotors do have a couple of very specific braking advantages.
1) The larger the diameter, the lesser required clamping force to decelerate the car via leverage (means lighter pedal pressures as well - something that I like as a driver)..
2) More surface area means better radiation and cooling of that energy which is converted to heat. You'll also find less heat (read number 1 above again).

Then there are some potential disadvantages which can be minimized by proper sizing.
1) Increased rotational weight
2) Increased unsprung weight

All that said - Alex is really more after the Bling factor I think. But I don't think this is necessarily a bad thing. Heck I think we all appreciate the "right" kind of bling on our cars...

 

[Eric]

All that said - Alex is really more after the Bling factor I think. But I don't think this is necessarily a bad thing. Heck I think we all appreciate the "right" kind of bling on our cars...

Right. To each his own... (and please keep that in mind when I eventually get my build up and running!).

And I apologize to Alex for my part in the thread drift.

Eric

 

[Alex]

As soon as I start hearing 'measuring and machining' I back out :laugh:

Oh well, I'll look at it like this - adding an inch onto the overall rotor size would probably have added unsprung weight. Weight is bad, heh.

 

[Mesa]

I´m not following F1 to deep in the last years ( to much restriction and rules). but aren´t they still have to run 13" wheels, so the rotors can´t be that big or ?

TOM

You are correct Tom about the size, during the F1 season there were quite a few wear/heat related brake issues. Me thinks if they could run bigger rotors they certainly would.

 

[Craig Gillingham]

does anybody want to buy a complete set of unused SLC wilwood brake calipers and rotors?
havnt a clue what shipping will be to USA tho.