Does anyone know if true lightweight rotors exist?

[crazypete]

I have looked and looked and all I can find is sights boasting of the stopping power of their crossdrilled and slotted rotors but nobody mentions the weights. I read into the archives last night and determined that CD and slotted rotors are bling and wont be at proper operating temperature for street use.

I just finished installing the mc-2300-C rear disc brake conversion kit (same as turbocoupe) and those rotors were light. I mean one could lift them with 1 finger. Last night, I took my front rotor off for the first time ever and WOW that thing is heavy! Now, I already have the 73mm caliper and hawk pads + SVO MC and PV, so I think I have stopping power covered but I could realy stand to lose some weight on these rotors!

Anyone know if some significantly lighter rotors can be found anywhere?

Thanks all!

Happy holidays!

CrazyPete

 

[85_SS_302_Coupe]

Well this probably doesnt help you, but i was reading about F1 cars actually using carbon fiber disks!! That's pretty sick IMO.

 

[crazypete]

Those sound expensive!

Plus such race parts are usually used up after 1 race. Heck the guys change tires a couple times in a race and the heat qualities are probably quite different.

One idea I had was that while I was hammering the old caliper off the rotor, at least 3-4 pounds of scale fell out from inbetween the vanes. I think maybe if I dropped the rotor a few times or lightly hammered it, I could carve off a few more. Plus the rotor has a larger diameter than the pad's contact surface...maybe take a litte off the outside and reduce the diameter to matach the contact surface.

 

[giddyup306]

Strange makes them. There's another company that makes them but I can't remember who it was. And both kits are expensive.

 

[crazypete]

Homemade lightweight rotors!

I was looking down into the rotor right before install and got annoyed at all the scale and rust in the vanes, so I went on a mission with a large screwdriver and went through each vane and simply broke off all loose scale. Man, there are a lot of vanes in a brake rotor!

When I was done, there was a serious pile of scale and rust sitting under each rotor. I picked up the rotor and wow! It had gone from heavy to medium weight. I guess rust wieghs a lot. Plus I bet it sheds heat better now. Images in my mind appeared of sandblasting the rotors but then I just reinstalled them.

I think everyone needs to descale their rotors next time the brakes are changed.

Happy new year all

 

[Michael Yount]

Pete - the rear brakes on a front heavy car like the stang do very little work in actually stopping the car. That's one reason the rear rotors are so small/light. They simply don't need to be very stout. Especially with a stock-style suspension that allows a lot of nose dive - most of the work of stopping the car takes place at the front.

And I've got news for you - if you check out the larger rotors that folks put on the front (13" rotors and such) they're probably heavier than the stock rotors just because of the diameter increase alone. The extra weight is not all downside - the more mass the rotor has, the more heat it can absorb/reject without getting to temperatures that are too high for effective braking. So don't go too crazy on your light-weight rotor thoughts. The carbon rotors referred to earlier work because they don't lose braking efficiency at extreme temps like the metalllic rotors do. And yes they are light. And yes, they are EXTREMELY expensive. An F1 braking set up alone would cost way more than most of our cars do. Keep in mind - that's an issue for F1 primarily because the rules dictate they have to run a 13" wheel - so their rotors are extremely small.

Grooves/drilling rotors - those were come up with because in the past, when the pad was pressed against the rotor (pressure, heat, friction) it gives off gases. In the old days, pad compounds were such that the gas could actually form a boundary layer which inhibited the build up of friction and limited braking effectiveness. The grooves or holes allowed the gas to escape which prevented the problem. It's identical to what happens when a tire hydroplanes on water - except instead of grooving the pad (tire grooves), they 'groove' or drill the rotor. However, pad construction has changed over the years. With most quality contemporary pads in street use, it's not an issue any longer - and so, grooves and drilling on street cars are more about bling than anything else.

But here's the real kicker - the brakes don't stop the car. The tires do. So be sure you've got enough wheel/sticky tire on the front of the car -- for a single hard stop (emergency stop on the street) - that's the best gain you can make in stopping power. If your front brakes will lock up your front tires, then bigger brakes won't stop you any sooner for the first stop. They will help you stop short multiple times, while the stockers get overwhelmed with heat (like on a road course with continual lapping) - but on the street - if your brakes will lock up the tires, then big brakes are pretty much bling too.

 

[Michael Yount]

Descaling the vented part of your rotors was a fine idea - despite your subjective measurement of the results, I doubt you removed more than an ounce or two of weight. But you probably helped the rotor with it's ability to transfer heat to the air (like cleaning the bugs out of your radiator fins) and that helps braking performance in terms of putting off brake fade for a longer period of time.

 

[Speeds8erM-1]

What about aluminum drums for the rear? I have heard of them for these cars but nobody really has any weight specs. I made a post on the Corral awhile back and didnt get the weight numbers I was looking for.

There are lightweight brake kits for the cars though, Aerospace is a popular drag type setup, there are quite a few different cars around here running them.