Titanium Brake Shims: Special Buy for ET Members

[Evil Twin]

I recently helped Alan of TakSpeed test-fit some titanium brake shims to insure they'll work with the stock Lotus brake system. For those of you who don't know, titanium's a poor conductor of heat -- some race-brake and high-end setups use titanium in the pistons -- so inserting a thin titanium shim between the pad and the piston eliminates that mechanism of heat transfer (you'll still get radiant heat transfer, but a lot of the heat that ultimately reaches your fluid comes from the pads to the backing plates to the piston/caliper). For more information, see this thread on Alan's site.

I admit that I was skeptical about the need for these shims on the Lotus, but I'm glad I have them: at the very least, it'll increase the period between when I need to bleed the brakes (I'm lazy, so the less work I do on the car, the happier I am), and I'm convinced that it'll extend the life of the caliper seals and such. In any event, they're also easier to install than the stock shims if you're still using them. And, if you're running slicks, you can be confident you'll never boil your fluid, which is good for the peace of mind.

In return for the help, Alan's agreed to offer, on a limited time basis, a 15% off electronic "coupon" to the Lotus community. To take advantage of this, go to the following page on Alan's site to order. Use "elisetalk" (all lowercase, one-word) as the coupon code.

For questions on the product, pls. contact Alan through his site. I'm neither an agent on his behalf nor do I know much about the product, save that it makes sense, particularly in the racing community, the design is good, and I'm happy with mine. I can vouch for Alan as a great guy to deal with.

Best,
Twin

[Thomasio]

I'm wondering why they chose to use titanium, when ordinary (inexpensive) stainless steel has roughly the same thermal conductivity? I can't imagine four stainless shims could be $79.00?

Thomas

[Evil Twin]

Because you'll save a few ounces? Like I said, I'm just trying to help out the community. You'll have to raise the question with Alan (via his site) if you want more info.

[Thomasio]

Genuinely curious, not shooting it down. For all I know, sheet titanium cuts better and saves on manufacturing. (Probably not, but there must be a reason they chose Ti over SS.)

Thomas

[25psi_Elise_Killer]

Copy & paste of Titanium shims from an Evo vendor:

The problem of brake fluid boiling is simply traced to heat transferring from the rotors and pads directly into the fluid through the caliper pistons. When brake fluid boils, it releases air that is normally part of the molecular structure of the fluid. This air is compressible of course, and the brake pedal goes to the floor instead of moving the caliper pistons. Production cars tend to suffer from this on track days more as they don't usually have the extensive cooling duct and exotic brake materials as true racing cars. True racing only brake calipers generally come with titanium caliper pistons for one reason. Titanium as a material, has low thermal conductivity. This means that it is very bad at transferring heat. Which is good if you are trying to keep your fluid cool.

The Girodisc solution to help prevent fluid boiling is to use a thin titanium shim placed between the pad back and the pistons, to keep the braking heat from transferring into the pistons and fluid. Here is a comparison of materials and their relative thermal conductivity ratings
Titanium 6AL-4V 6.7 W/mk Steel 52 W/mk Aluminum 130 W/mk

You can see that Titanium will transfer far less heat than steel and especially aluminum. For cars that are going to see hard or multiple track days, these shims are cheap protection from loosing the pedal due to boiling at the wrong time and making the day very expensive.

[Thomasio]

Originally Posted by 25psi_Elise_Killer

Copy & paste of Titanium shims from an Evo vendor:

Here is a comparison of materials and their relative thermal conductivity ratings Titanium 6AL-4V 6.7 W/mk Steel 52 W/mk Aluminum 130 W/mk

You can see that Titanium will transfer far less heat than steel and especially aluminum.

That's very misleading... while "Steel" may be a 52 W/m-K for thermal conductivity, stainless steel is more like 16 to 20 W/m-K. See http://www.lenntech.com/Stainless-steel-304.htm for instance. Why was SS left out of that list?

Also, at the thicknesses that shims are... there will be negligible real-world difference between plain titanium and plain stainless steel.

I'm not buying it. Literally.

Thomas

[®ob]

I have yet of hearing of anyone boiling their fluid on an Elise. I don't see it happening, especially if you run Motul or SRF. Race teams might buy off on these however as they are looking for the .01% advantage.

[ace10]

would this not require the grinding off of pad material in order to insert a shim in that limited space?

[Evil Twin]

Again, I'm not the guy to ask, but my two cents are:

1. Which material gets used -- stainless steel or titanium -- probably doesn't matter if both are roughly comparable in terms of conductivity. Titanium sounds better, though, maybe that's the reason.

2. Whether you need the shims is your call, but I'm glad to have them, if only b/c they'll reduce my interval for brake bleeding and (I believe but can't prove) will extend the life of the seals in the calipers by keeping them from getting as hot. I don't think it's about brake fade -- but I said that in my first post.

3. You don't need to do any grinding of your pad material as these shims are thinner than the stock shims, which can be fitted to both the stock pads and to aftermarket pads, like Pagid RS-14's.

[Thomasio]

Originally Posted by Evil Twin

Again, I'm not the guy to ask, but my two cents are:

1. Which material gets used -- stainless steel or titanium -- probably doesn't matter if both are roughly comparable in terms of conductivity. Titanium sounds better, though, maybe that's the reason.

Except that titanium is far more expensive. Can you imagine $79 for stainless shims?

Thomas

[Evil Twin]

Thomasio, your point's fair, but if you're gonna get on the soapbox about the cost of aftermarket parts -- particularly ones that actually work and provide a useful purpose -- when you're talking about a few bucks in potential savings from picking a different material, don't you think you could start with all the money spent on carbon fiber? Or, how about aero stuff that looks cool but has never been tested in a wind-tunnel? Or, how about all the engine mods that don't add power? There's so much stupid money spent on "mods" -- for our cars and others -- that add no value (at least in my book) that it leaves me shaking my head...

[FlyLo]

Originally Posted by Thomasio

Except that titanium is far more expensive. Can you imagine $79 for stainless shims?

Thomas

Um, yeah. http://www.racingbrake.com/350Z_EVO_...er_p/bs961.htm

"RB brake shims (brake noise and heat insulator) are designed and manufactured to alleviate the squeaky noise that can arise under low speed and light braking. These shims are made of high strength steel plate and coated with high temperature silicon rubber and have proven to effectively eliminate or substantially reduce noise in addition to shielding heat transfer to the caliper. "

$70

[Thomasio]

If the price premium is $9 to go from stainless to titanium, then I suppose the point is moot. I retract my question and concede defeat.

Thomas

[TimMullen]

Originally Posted by FlyLo

"RB brake shims (brake noise and heat insulator) are designed and manufactured to alleviate the squeaky noise that can arise under low speed and light braking. These shims are made of high strength steel plate and coated with high temperature silicon rubber and have proven to effectively eliminate or substantially reduce noise in addition to shielding heat transfer to the caliper. "

$70

Not exactly apples to apples...

These shims are rubber coated to prevent noise. They are not the same as shims designed to stop heat transfer. I suspect that the coating is the cost driving factor for these shims...

[tesprit]

Originally Posted by Thomasio

If the price premium is $9 to go from stainless to titanium, then I suppose the point is moot. I retract my question and concede defeat.

Thomas

Not to stir up the fire again, but if you were making your own shims, a small piece of stainless steel sheet scrap will cost you next to nothing (maybe free) and it is a lot easier to cut than titanium. Using a small metal cutting bandsaw, you could make a set in almost no time using stainless.

[codymac]

Originally Posted by ®ob

I have yet of hearing of anyone boiling their fluid on an Elise. I don't see it happening, especially if you run Motul or SRF. Race teams might buy off on these however as they are looking for the .01% advantage.

I see you didn't go to LOG this year either then.

[rugger1345]

Originally Posted by ®ob

I have yet of hearing of anyone boiling their fluid on an Elise. I don't see it happening, especially if you run Motul or SRF. Race teams might buy off on these however as they are looking for the .01% advantage.

It happened to me on my first (so far only) track session over at Hallett. I think it was the stock fluid as I doubt the owner flushed the fluid at any time over the life of the car. I ordered a brake bleeder kit and some Motul RBF 600 for my next track day.

[vizwiz]

Originally Posted by tesprit

Not to stir up the fire again, but if you were making your own shims, a small piece of stainless steel sheet scrap will cost you next to nothing (maybe free) and it is a lot easier to cut than titanium. Using a small metal cutting bandsaw, you could make a set in almost no time using stainless.

Hi Folks. This is "Alan from Takspeed". I found this thread when doing a google search. Seems some additional explanation here might be worthwhile.

We use 6AL-4V Titanium Alloy, which is expensive, but has HALF the thermal conductivity of stainless. That's a pretty significant difference, and our major reason for going with the alloy. In addition however, stainless steel has mechanical strength issues at these thicknesses, and would tend to smudge over time. Our alloy shims retain their integrity and can be used over and over again as you change pads (unfortunately for our repeat sales ).

As for the thickness, we went with the thin shims so that they would fit even with new pads after they have been bedded. The shims are designed to fit over the caliper pins so that they can be stacked as your pads wear down, INCREASING the thermal barrier as the pads wear down.

As for the price, they're on sale now for $15 off, but won't be for long.

Depending on where you are in the personal money/time balance you might want to make your own titanium shims and save a few dollars, but I think by the time you go through the process of getting the Ti and paying waterjet small job fees you will find that we are offering these at a pretty reasonable price for the value.

[dfa2100]

Just a random question... but why not use a ceramic of some sort? Too brittle for the application, or too expensive? Or both?

[fishguy]

My completely stock set-up was more than fine for my style of braking.
I used to roadrace motorcycles and the brakes was where I could make many passes, and position myself under other riders.
I am very hard on my brakes, and again, the stock pads, and fluid were fine. The car outbraked anything I saw on the sessions I was running in.
if its not broken, why fix something?
.02