FruiTay

I'm curious how effective titanium heat shields are and if I should install them in my brakes. I have the stock setup with ducts, SS lines and will be getting SS caliper pistons. Do you think the heat shields would be a good addition?

Thank you for any good replies!

Solofast

Titanium has about 1/10 the conductivity of aluminum (12.6 vs 136 BTU/hr ft^2) so it has the potential to do some good in that it doesn't conduct heat as well as aluminum, but realize that thickness comes into the equation too and a really thin piece of Ti isn't going to do much good.

In reality there is also the additional joint between the two pieces that also inhibits the heat flux, so there is some good from that too.

Basically it all helps, but not a huge amount.

What happens is that you do a number of things, each on their own that don't make a big difference, and it all adds up.

You can run a heat transfer analysis and if it drops the temperature in the caliper 25 F is that a big deal? The answer is well, if you're right at the point where you are boiling the fluid it is a big deal. But if you're way past boiling the fluid it doesn't help much.

Stainless steel actually has lower conductivity than titanium (304 has a conductivity of 8.09) so it's about on third less conductive the titanium.. But then stainless heat shields don't sound as sexy as titanium....

The advantage of stainless pistons is that not only do they have much lower conductivity, but they are stronger at temperature, so you can have a much thinner wall on the piston, which conducts even less heat.

It's interesting in that the titanium actually has higher conductivity so they may not do much when added to stainless steel pistons. The only advantage for them in that case is that there is that added joint that the heat has to go through and that is a high resistance to heat flow, so they may help some, but don't expect miracles..

FruiTay

WELL DONE SIR! Ok, I will save the bucks than. Thank you for such an informative reply.
Take care!

KNSBrakes

They do insulate the piston/caliper as noted and correctly it may or may not cumulate to help w/ fluid fade.

The real benefit I see is shielding the piston dust boots from the race pad heat. On a mildly tracked car that see's road use this can be helpful.

ErnieN85

they saved me from changing the boots after every track weekend.
so they will pay for themselves at least on the front

YYZ06

I've been running them inboard side only for years. They do seem to save the boots.

greendot

Good stuff, as usual. Got the specifics on the various grades of stainless or doesn't it matter? Wish I'd have been aware of this before I made Titanium for my stock 85 brakes, but can make some stainless if I want to.

GO_BLUE_VETTES

I have a set of stock C5/C6 caliper Ti heat shields for sale here:

https://www.corvetteforum.com/forums...post1589406257

Untitled by go blue vettes, on Flickr
Untitled by go blue vettes, on Flickr

FruiTay

Haha, this is why I was asking

Solofast

Bruce,

I just picked 304 because the data was on the page that also had the thermal conductivity of titanium. That way I was sure I was getting apples and apples. If I were going to make some I'd look up a couple of stainless steels and see what looks good. I don't think strength matters, you're pushing on hot aluminum and that is like butter up there.

If you really want to insulate the pistons you could coat the shim with about .020 of thermal barrier coating. That would make a huge difference in terms of caliper temps, but it won't be as cheap as a thin shim.

69427

Went through the same process, and have been running SS shims for the last 20 years, first on my stock C3 calipers, and currently on my Wilwood calipers.

You caught my engineering curiosity with the thermal barrier coating option. Any stuff out there available to the average guy (that doesn't require sending parts out to the big race supply shops)?

LateBreak

If the boots are all you're saving, just don't run the boots

Solofast

There are a lot of places that will do TBC coatings and sending a set of shims out doesn't cost that much. I'd just see how much it costs to do it. Swain coats pistons for $28 each. Since you probably don't need to mask these things you could coat them with .015 thick "White Lightening" coating and that would do it. Something like that would make a set of shims really effective. We use an industrial coating house in Detroit that is pretty reasonable. They charge us a setup charge and then charge for the spraying and it isn't bad.

I've seen a few "do it yourself" coatings for piston tops that are designed to be sprayed on and then baked and some of them seem to last OK on pistons, but piston coatings are typically .005" thick and if you want a real TBC you need about 3 times that. Plus the fact that aluminum pistons don't usually get hotter than maybe 300 F and these brake shims are going to get a lot hotter than that. To what you want you probably need to have it flame sprayed. Typically the coatings that you want are used on headers.

Still, a DIY coating of .005 on both sides of a shim would probably do the job and it wouldn't cost much at all. Probably worth a try.

greendot

Thanks Manny,
Interesting you suggest a .020 coating when some of the titanium shims are .028 - .035.
And if I decide to coat I guess I'd do the Titaniums that I've got. We'll see how things go this summer. I put duct blowers on over the winter and if I never use them then I'm good. If I do then I'll take another step.

Solofast

We typically did .020 on jet motor parts. Swain recommends .015 for their exhaust coating. If you did a .015 shim and .015 coating you'd have a good combo.

Also this place offers shims for Corvettes and also for a "nominal charge" will have them coated with TBC, but they don't say how thick the TBC is. If their doing .005 of piston coating it isn't going to do much for conduction, but it would probably help the seals and dust boots. http://www.girodisc.com/product_index.asp

greendot

LOL, they don't even offer anything for a C4, let alone my baby brake C4. That's why I made my own + extras. I could also double up my Ti shims I think.