thai

since the warped rotors that i had a year ago, i have been putting a very thin layer of these silicon thermal paste/grease between my wheels and rotors to better transfer heat from rotor to the aluminum wheels. it is kindna like having a heatsink on the rotor. i re-torqe the lug nuts properly. i'm just paranoid if there is anything i should be worry about.

the thermal grease is used to mount heatsink on cpu, mosfet power transitor to amplifier heatsink, and you can get it from radioshack.

what do you guys think?

civic4982

sounds kinda stupid to me. if I remember right the grease is pretty slick. anywyas, if it's computer grease it won't be able to handle the high temperatures and burn off the rotors as soon as you get on those breaks. a heatsink on the rotor to the wheels is already going through the bolt, you're just helping transfer the heat more quickly. personally I think it's a waste of time considering the positive aspects are minimal. The heat will transfer anyways no matter what kind of paste you use. I doubt the material can handle those intense temperatures without evaporating off.

DRM600

the kind of heat built up through braking that could cause warping would be too great for thermal grease, at least the kind used for cpu heat sinks. i seriously doubt that it can transfer more heat to the wheels to act as an effective heat sink more than the air will while the car is in motion.

ChadT

I put anitsieze on mine there just to prevent rust on the mounting surface for the wheel.

thai

actually this stuff will not burn off, at least not for me. this is only to allow a better contact between the wheel and the rotor, where there might be microscropic spaces between them, and that is their purpose, to fill up the microscopic space to allow better heat transfer from brake rotor to wheel.

civic4982

the effective heat trasnfer is very little and can only help transfer an extra small amoutn of heat. If you install a CPU without the grease you'll notice that the temp. difference will only be about 4-5 degrees. 4-5 degree difference for the small contact patch b/t wheels and brakes is nonexistent change in temp considering the size of the rotors and how muich heat is in them. It's not like this will magically make the wheel temperature the same as the rotor temperature therefor coolking it faster b/c of a larger surface area. imho you're wasting your time and grease. You might as well get wheels that look like giant heatsinks.

EDIT: I was incorrect on the 4-5 degrees. It's actually only 1 degree.

http://www.overclockers.com/articles662/

I did some reasearch and even using the BEST thermal greases temperature decrease will only be 1 degree.

Let's give it the benefit of the doubt that the 1 degree change is a percentage that is linear.

1 degree change per 50 degrees is 2% change. The general range of braking is between 300*C and 800*C.

At a 2% reduction you're looking at 394*C and 784*C.

It's not a big enough difference to truly matter.

thai

i will probably agree with you that it may not be neccessary. i'm sure this was already taken into account when the engineers at honda design the break system.

however, we are here to do what we can to improve the performance of our car. little here and little there.

i think you miss read the entire article that you've linked.

"Thermal grease can only go so far - even the most theoretically efficient grease might only yield another 1 C compared to what's now available. "

basically what they were saying is that the best thermal grease out there may only out perform the regular thermal grease by 1%.

what i'm talking about here is with and without. try to run your cpu without any form of heat transfer material and you you see a huge temp increase, maybe in the range of 10-20% increase in temp.

NSX-Tuner

There is also the possibility of the grease leaching onto the rotors and screwing up the pads, not to mention making it dangerous.

soopa

its just useless.......... warping has nothing to do with where the rotor hat touches the wheel.

warping occurs on the disc surface.

civic4982

I guess I may have misread it but there WILL not be a 10-20% decreas in temperature on the rotors because of their high temperature. the CPU doesn't run NEAR that kind of temperature. At most it'll run around 60 degrees and that's probably going to fry it. You'll notice that most graeses are good within a certain temperature range and then they do not transfer heat well. CPU grease is not made for even 300 *C.

phrocker

There are several types of thermal grease. Silicon based greases ( most likely what you have ) has an maximum operating temperature of up to 350C, yes celcius.

If you have ever removed your heatsink and any grease or pad from your cpu, it will not run at 60C, it will run upwards of 500 C if it's an AMD athlon. I have personally seen a duron reach 898 F, tested using an infrared laser sighted thermometer, obviously reading the die. For those of you who visit tomshardware.com, you may recall they did a similar experiment. As in his experiment, my motherboard and CPU went up smoke due to thermal death. Temperatures such as 40, 50, or 60 C occur when heat is conducted into the heatsink where it is dissipated, not without the heatsink, where the cpu's real temp can be read.

thermal grease is a conductive compound, meant only for heat transfer, not dissipation, therefore it would really do no good as areas where metal to metal contact are minimal would dissipate heat much less. Rememer air has poor thermal conductivity.

civic4982, I used arctic silver, and I've noticed a 6 degree drop since the break in period. It depends on what compound was used prior to the thermal grease they installed.

BTW, the thermal grease at radioshack is bottom of the line silicon base grease. Silicon greases have a max temp of 350, though their working temp is -10 to 250. Once you exceed 250, their effectiveness is limited, but heat transfer still occurs.

Remember, the heatsink is what does the work. Thermal grease is only there to fill the grooves and indentations common after heatsink seating and cpu manufacturing AND ensure as much heatsink to cpu contact occurs.

It's my opinion the thermal grease could handle the heat of the rotor, but I don't think there is enough contact to make a difference, nor do I think it will be effective at all.

Oh, and that overclockers article is just one of millions online. You can find thousands of more reputable sites that say silver grease is the best thing since sliced bread.

thai

guys i'm not talking about putting the stuff on the rotor where the break pads contact the rotor. i'm talking about where the wheel meets the rotor. there is a lot of space of contact, and this is where i thiink the heat grease can help in transfering more heat to the wheel, where the aluminum wheel serve as a cooling device like a heatsink.

soopa

thai: it simply doesnt work like that... you are wasting your time. see above comments. lol

phrocker

heatsinks are specifically designed for heat dispersal, your wheel is not. It may help to disperse heat, but remember, aluminum is not the best conductor of heat. Anyway, your wheel is not pure aluminum. Depending on what it is alloyed with, it may not conduct heat even as well as pure aluminum. Point is, all you're probably getting is piece of mind, but if that is what you want, then more power to you.