JeremyL

there seems to be a way of using heat exchangers to cool just about everything from auto tranny fluid to power steering fluid to air from a turbocharger. I had kind of an interesting idea about a way to cool a cars brake fluid. Since the rotors and pads are not the only componenet that can fade due to heavy repeated use, fluid is just as prone to overheating I was thinking if it would be plausible to atleast for the front brakes to rig up some type of heat exchanger that the brake fluid could travle through on its way to the calipers to be cooled so you would be less likely to be subject to fluid fade

MattD@Stoptech

j00 may want to think about that a bit more...

.RJ

Its a closed system, there's no circulation.... if there were circulation the system wouldnt work without a series of check valves (failure points).

Cool the rotors with ducts, no need for coolers. The "heat exchanger" is already there

JeffS

There are aftermarket products that allow for circulation of brake fluid.

It would require re-lining your brake system and calipers with balance tubes (4-piston or greater typically).

GSpeedR

The boiling fluid is causes by high pad/rotor temperatures so why not go a step farther and reduce the heat that causes fluid fade: at the rotor/pads. For options how, see above.

MattD@Stoptech

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JeffS &raquo;</TD></TR><TR><TD CLASS="quote">There are aftermarket products that allow for circulation of brake fluid.

It would require re-lining your brake system and calipers with balance tubes (4-piston or greater typically).

</TD></TR></TABLE>

...self bleeding to b00t...

JeremyL

i had thought about that since unlike tranny, ps or coolant fluid brake fluid doesnt really circulate...i guess having a duct leading from the front air dam to the rotor would be a pretty nice idea

Haberdasher

You could try increasing the surface area of the hard brake lines to disipate heat. Just like adding a heat sink to your CPU in your computer. I don't know how you'd do that exactly, though.

.RJ

You already have a heat sink! Its the big **** cast iron disc that spins around inside the caliper!

And guess what... its already got cooling vanes too!

JettaRacer

They're called water cooled calipers. Seen them on a number of BTCC cars. Very neat.


Modified by Zoro at 2:57 AM 4/10/2004

JeffS

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Zoro &raquo;</TD></TR><TR><TD CLASS="quote">They're called water cooled calipers.</TD></TR></TABLE>

Well sure... if you've got THAT kind of money.

Mohudsolo

I've seen pics of nascar stuff with brake fluid coolers but no good explanation of how they work. My understanding was that they do circulate the fluid, so I assume assorted checkvalves and other fun plumbing.

JettaRacer

Well... there is very little point to actually try and cool the brake fluid. It's much easier and practical to cool the caliper. Like you say, unfortunately it is expensive. Otherwise, a good system is to have a recirculating system - requiring all sorts of system changes. 4 pot calipers, a number of one way valves, extra lines, etc. The neat part about recirculating systems is that they are auto-bleeding.

.RJ

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Zoro &raquo;</TD></TR><TR><TD CLASS="quote">It's much easier and practical to cool the caliper. </TD></TR></TABLE>

No, the rotor!

JettaRacer

Of course, but fhere is only so much that can be achieved by air cooling the surface of the rotor and caliper.

.RJ

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Zoro &raquo;</TD></TR><TR><TD CLASS="quote">Of course, but fhere is only so much that can be achieved by air cooling the surface of the rotor and caliper.</TD></TR></TABLE>

If you need more thermal capacity and you are cooling the rotor and the caliper, you need a bigger rotor.

Cooling the rotor should be your first priority.

JettaRacer

Well, if you're driving a BTCC car and you're already running brakes that barely fit in your 19" wheels, and you still run out of thermal capacity, then you may think of cooling the calipers. That's why they exist. I'm not telling somebody to use 9.5" solid rotors and water cooled calipers. The original question was about cooling brake fluid, I just merely pointed out what the most extreme brake cooling techniques are... jeeze.

JeffS

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .RJ &raquo;</TD></TR><TR><TD CLASS="quote">
Cooling the rotor should be your first priority.</TD></TR></TABLE>

Cooling the rotor is going to have a minimal effect on caliper (and thus fluid) temps. At best, you'll cut down on the radiant heat transferred from the rotor to the caliper.

I don't know why you're fighting the idea that the brake fluid could benefit from cooling of its own. The brake system design of many, if not most, professional racing teams seems to say that there is a benefit. Whether it's of any use to a honda is another issue entirely.

Haberdasher

It seems to me that anything you can do cool the fluid in the hard lines would reduce the likelihood over boiling the fluid. It should reduce the chances of developing a soft pedal near the end of a race.

But RJ seems to know everything so I'm wrong...

Eddiebx

but does the hot fluild really even make it back to the hardlines? usually the fuild boils over in the calipers, though i guess it could transfer heat through the softlines and make it to the hardlines eventually, who knows, i never had a problem with boiling fluid over.

ScreaminD16

Most NASCAR race cars use a device much like the ones you can buy in the store. I found one for anyone that is interested in cooling the brake fluid.

http://cgi.ebay.com/ebaymotors...&rd=1

NickR

What fluid is being used that boils so easily?

I use Castrol SRF. It's not cheap ($70/bottle), but I've never boiled it...

Warren

If I get a fresh bleed of Neosynthetic, it generally lasts 2 weekends of racing. A lot more if I'm just doing schools. I like it quite a bit more than Motul. For those of you who ran Cobalt's brake fluid, this is extremely similar.

Motul sucks up water faster and it causes a seriously squishy pedal. The brakes will be there, but the pedal feel is horrible. I still don't understand this as it's a liquid and should be pretty much incompressible.

I don't like ATE Superblue, because I tend to boil it. Yes, it's pretty good, but not if you're going to rail the brakes hard.

Warren

Lyonel 13H4

Brake circulators are a very simple device, and according to some Porsche racers that I know they really work and as someone said before, are self-bleeding.

As for the Super Blue brake fluid, I like it! I bleed my brakes before I leave for the track and don't touch them generally (assuming the master cylinder hasn't puked or the pads haven't reached the end of their life) for the remainder of the weekend.

JettaRacer

looks like this... need 4 pot calipers in general, with balance/recirculation tube, and a valve. Needs extra flex lines, etc...

http://www.dpiracingproducts.com/lcsbbrake.htm