Steve Dallas

Do they actually do anything useful?

Brake cooling is my biggest concern on the track right now. I know I need to just bite the bullet and duct them, but I really don't want to hack up my car yet.

Since switching to Carbotech pads, I am enjoying the linear modulation, but I am also generating more heat due to the lower initial bite. As a result, I have been dry boiling fresh fluid and experiencing fade on the track toward the end of each 20 minute session.

I know a guy who swears by titanium shims from a company called Hard Brakes. I contacted them to see if they make shims for our pad shape, and they do not.

Undeterred, I found the Ti alloy (6AL-4V) sheet metal they use and bought a 12" x 24" x 0.26" sheet of it for $20 with the intention of cutting my own shims. I may leave a little extra metal on them to bend up as heat sink "wings" of sorts.

Has anyone used Ti brake shims? Thoughts on their performance? Am I wasting my time and money?

NotAPreppie

What are they supposed to accomplish?

Steve Dallas

They are supposed to block a significant amount of heat transfer between the pad and caliper piston. No idea if they actually work, though. The laws of thermodynamics have me scratching my head on this one.

pcs

iTrader: (2)

if they do that, where does the heat go? Could the downside be more heat in the pad and then going beyond the operating temps of the pads...?

boricua13

Titanium has low thermal conductivity, so in theory it should work as they would not allow as much heat to be transfer to the caliper.
Titanium Brake Shims - How Brake Shims Work | HowStuffWorks

Steve Dallas

Yeah. That's a good point and one I have pondered.

The reason I am thinking about making some and trying them is just a few degrees F may prevent boiling fluid. Hard Brakes claims more than 100F difference. The pads I am using are rated for 1400F. According to the caliper paint I have put on the pads, calipers, and rotors, my pads are not getting anywhere near 1400F, so they have plenty of headroom to absorb some extra heat.

I'm skeptical, but maybe it will work?

NotAPreppie

Titanium's low thermal conductivity is still pretty high relative to non-metals; it's just not as high as other metals (aluminum, copper, gold, silver, etc).

Honestly, it sounds like a false solution.

Steve Dallas

Yep. Which is why I am skeptical. Still, I only need a few degrees...

EarlQHan

Titanium is used because of its abilities to stand up to high heat. However, you can used stainless 304 for similar results at a fraction of the cost.

Black2010R3

iTrader: (1)

In heat transfer you also have to take into account losses where two things are touching, so it's a larger benefit than just the thickness of the shim times the thermal conductivity, as you're adding another layer where two pieces touch. I've read that they do work, but as pointed out, it'll put more heat into the pads.

Maybe try some higher boiling point fluid? Also, removing or trimming the dust shields behind the rotors helps remove more heat from the brakes.

boricua13

How about air ducts? Faster cooling eliminating the need fro the shims.

Steve Dallas

I just bled out the ATE 200 I had been using in favor of Wilwood EXP, which has a higher dry boiling point. Man, I'm going to miss the price of ATE.

I have heard that about cooling benefits of removing the dust shields, but I have never seen any data proving it works. My shields have fairly large scoops that direct air into the vanes, which could be of some benefit. Removing the shields, which are also heat shields, exposes several joints and other bits associated with the hub to increased heat, which may be detrimental.

Please see sentence number 3 in the OP.

IamFodi

iTrader: (1)

Can Wilwood or some other vendor throw together some stock-sized 2-piece rotors that would work with your chosen pads? If the rotors cool more efficiently, the whole system might end up cooler as a result.

Steve Dallas

I'll put in a call to Goodwin Racing today and see what Brian has to say. If anyone can put something like that together, he can.

Black2010R3

iTrader: (1)

I was having a little fade and removing the dust shields helped. They can also trap the heat in and those scoops are completely hidden by my 17x9 track wheels. I'd like to trim them so that they only act as heat shields for the ball joints and put them back on eventually.

Steve Dallas

The jury is still out, but I conducted an experiment today. I used a Centric shim on each inside front pad for today's track day. Without any Titanium voodoo, I experienced very little brake fade as compared to last month. As such, it appears any shield between the pad and caliper can make an appreciable difference.

blu3dragon

iTrader: (1)

I use the OEM metal backing plates. They do make a difference. Another layer would help more, but the problem I find then is they warp and start to push the pad away from the rotor, which kind of defeats the benefit of not boiling your fluid.

One trick I learned recently is that you don't need to go through a full bleed procedure to restore pedal feel at the track. instead just loosen the brake reservoir cap, loosen the bleed valve on one front wheel until you see a drop of fluid form on top. Close the valve, dab it up with paper towel and do the same on the other side. You don't even need to jack the car up to do this, just turn the wheel so you can reach each side. On a hot weekend I might need to do this once per day. More than that and it is time for fresh fluid. This is with ATE typ 200.

I know removing dust shield helps some cars, but on this car I actually expect that will make things worse. The reason is that you then remove the air scoop on the dust shield, and even with 17x9 wheels, I have noticed my inner pads don't wear quite as fast as my outer ones...

Obviously some ducting is the real solution. I need to do that too...

Steve Dallas

I had another track day today. It was another day with no brake fade. The differences are that I am still running a cheap Centric shim on the inside pad on each corner, and my fluid is some mixture of ATE Typ 200 and Wilwood EXP. The mixture heavily favors ATE, as I'm a cheap bastard, and I have several liters of it on my shelf, so I went back to it.

The idea of bleeding gas at the track is intriguing. In my case, I bleed my brakes so often than any fluid fade I have experienced has been due to dry boiling, which does not produce any gas, but it is certainly something to keep in the back of my melon for when the time comes.

I still haven't done anything with the Ti sheet I bought. I'll get around to it at some point...

Todd TCE

Ti shims do a very good job of creating a improved thermal barrier. The heat is the heat and it has to go somewhere, putting it through the pads, backing plate, pistons and caliper body simply are not the most ideal locations. Ti plates fit behind the stock pads serve as a good barrier to that heat transfer.

For much the same reason you'll find Ti pistons in some high end calipers as well as other modular design pistons with either Ti or media such as phenolic shims to achieve the same goal. Radiant heat is lower but more over thermal transfer from contact is reduced.

While I stock them for my personal sales needs here is a company who carries quite a few shapes. *I have no association with them and I'd agree their prices are rather high... Ti Shims But lets face it; you're only going to buy them one time.