brake recirculator
- Thread starter keohep
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Ron Earp
Admin
It keeps fresh fluid on the backside of the pistons. Theory is that this fluid will be cooler and thus can help with brake fade. We fitted one to Jeff's TR8 race car and found it worthless. If you are having heat related brake problems duct duct duct duct duct. You'll lick the problem without the recirculator.
Absolutely disagree- Not saying that you should not use cooling ducts etc, but I wouldnt build another race car without one. The only downside I can see is that in a long race ( Hours,not minutes ) if you were to have a small leak in the system & the driver assumed it was just a low pedal or did not pit to have the fluid level checked, it would be possible to lose all or most of the fluid overboard. Another good reason to have the Cyl Reservoir inside where the driver can see, or a low level warning light.
P.S., If you dont want it send it to me, I will put it to good use!
Ron Earp
Admin
Sold that thing already. We found it didn't help our problem. The TR8 is a sprint car and the heating problems it had were not helped by the recirculator. If it did help, which I assume it did, the "help" was a of a magnitude smaller than the problem. Our longer term cars, the Miatas and Z, don't have recirculators either but their brakes are well ducted and have never exhibited issues (other than user error) over 13 hours and 2 hours respectively.
Used them myself with GREAT results - particularly in Enduros...
One of the really cool parts of using them is that you never have to bleed your brakes - they act as dynamic bleeders!
Sort of like two check valves (one-way valves).
The one that allows fluid to go into the caliper comes from the pressure side (master cylinder).
The other valve allows fluid returning from the caliper to go back to the master cylinder reservoir.
The return valve is a spool valve that is held shut when there is pressure from the master cylinder.
Somewhere around here I have a circuitry diagram - I'll see if I can dig it up..
One of the really cool parts of using them is that you never have to bleed your brakes - they act as dynamic bleeders!
Sort of like two check valves (one-way valves).
The one that allows fluid to go into the caliper comes from the pressure side (master cylinder).
The other valve allows fluid returning from the caliper to go back to the master cylinder reservoir.
The return valve is a spool valve that is held shut when there is pressure from the master cylinder.
Somewhere around here I have a circuitry diagram - I'll see if I can dig it up..
Ron Earp
Admin
It was also a bit of a mystery to me how that valve worked as I never found a diagram. Suffice to say, we didn't keep it on the car because
a) we really couldn't detect a statistically significant effect with it installed. We had the "before" data - fried brake calipers and burned up seals, and the "after" data - fried brake calipers and burned up seals and
b) we were not 100% certain of the valve's legality in the SCCA Improved Touring class.
In the end coating the pistons with a ceramic heat rejection coating, using some high buck seals, and improving our ducting designs really took care of our braking problems.
YMMV.
a) we really couldn't detect a statistically significant effect with it installed. We had the "before" data - fried brake calipers and burned up seals, and the "after" data - fried brake calipers and burned up seals and
b) we were not 100% certain of the valve's legality in the SCCA Improved Touring class.
In the end coating the pistons with a ceramic heat rejection coating, using some high buck seals, and improving our ducting designs really took care of our braking problems.
YMMV.
If you look in the current SCCA GCR - You'll find that they added a part about having only one brake line per wheel.. That pretty much precludes the use of a Recirculator..
We used to get by with the part of the rule book that said you could use any brake line circuitry routing.. Although they never did say that you could alter the reservoir to allow the returning brake fluid a place to go. I'll keep digging to see if I can find that diagram. It was a could of computers ago, but I have backups on my network..One thing that I "still" do today is to use Permatex RED or COPPER RTV on the backing plate of the disk brake pad. I put about an 1/8" coating on the back side of the pad where it contacts the piston(s), let it skin up (not dry though) and then install - bleed brakes immediately so you can get the pad/piston to get friendly before the RTV sets up. You end up with about a .030" skin of RTV that insulates the piston from the pad. It really does work!
Ron Earp
Admin
Hey Randy,
We using a titanium backing plate on our cars because pads and backing plates are free. Now our backing plate isn't just any old backing plate......it has cooling fins on it. Below is a picture of the exact setup. The Ti insulator protects the piston. And sandwiched between the piston and Ti plate is an extremely conductive piece of copper / ? metal that forms the heat sink.
Sort of stretches the letter of the law but thus far most other IT competitors have been receptive. While it is true that you can't use an allowed piece to perform a disallowed function, nowhere is it said that cooling your brakes is a disallowed function.
Ron
We using a titanium backing plate on our cars because pads and backing plates are free. Now our backing plate isn't just any old backing plate......it has cooling fins on it. Below is a picture of the exact setup. The Ti insulator protects the piston. And sandwiched between the piston and Ti plate is an extremely conductive piece of copper / ? metal that forms the heat sink.
Sort of stretches the letter of the law but thus far most other IT competitors have been receptive. While it is true that you can't use an allowed piece to perform a disallowed function, nowhere is it said that cooling your brakes is a disallowed function.
Ron
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Ron,
Don't know if you use a vented rotor in that application.
I bet if you rotated those backing plates 180 deg. the cooling air from the rotor would pass through those fins, providing even more heat transfer.
Also using the paste that was used under a GM style HEI module would promote further heat transfer.
S
Don't know if you use a vented rotor in that application.
I bet if you rotated those backing plates 180 deg. the cooling air from the rotor would pass through those fins, providing even more heat transfer.
Also using the paste that was used under a GM style HEI module would promote further heat transfer.
S
I like the backer plate idea, but the fins on yours should be at an angle or 90 degees off from where they are right now. As it is, you're not promoting airflow through those fins because they are blocked off by the caliper itself..
I've used everything under the sun to cool brakes. Back in the 70's we used water. Yes, we carried water onboard the Corvette inside the passenger door. There was a Windshild washer pump motor that would suck the water out of the two 1 gallon jugs and spray it on the front hub. Of course from there, it would go into the brake hat and ultimately out through the vanes of the rotors as steam. All of this was hooked up to a relay from the brake light switch and we had a master switch for the pump as well. This worked GREAT until they caught us and then outlawed the use of water to cool the brakes.
No problem though - the water was heavy anyway.
Next year we had a rack of freon cans inside the door.. That worked even better until we got caught again and then they outlawed the use of any agent for cooling the brakes.
I don't see that in the GCR anymore so maybe it's in that "gray" area once again!
I've used everything under the sun to cool brakes. Back in the 70's we used water. Yes, we carried water onboard the Corvette inside the passenger door. There was a Windshild washer pump motor that would suck the water out of the two 1 gallon jugs and spray it on the front hub. Of course from there, it would go into the brake hat and ultimately out through the vanes of the rotors as steam. All of this was hooked up to a relay from the brake light switch and we had a master switch for the pump as well. This worked GREAT until they caught us and then outlawed the use of water to cool the brakes.
No problem though - the water was heavy anyway.
Next year we had a rack of freon cans inside the door.. That worked even better until we got caught again and then they outlawed the use of any agent for cooling the brakes.
I don't see that in the GCR anymore so maybe it's in that "gray" area once again!
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Rears on the cars we ran typically did not get hot enough to require extreme measures when cooling... Your application may be different...
I started a scan for the file under the name I thought I saved it under before I left home. Hopefully it will have finished scanning through almost a Terabyte of files when I get home..
I started a scan for the file under the name I thought I saved it under before I left home. Hopefully it will have finished scanning through almost a Terabyte of files when I get home..
Hi Ron
Im building a DRB GT40#74 .Its not going to be a full on race car ,just occasional track day ,maybe the odd Targa Rally.
The thing is i put a low bid on one on Ebay and won it,now im wondering what im going to do with it, I liked the idea its self bleeding.
Id have to run return lines from the callipers to the circulator or resivour wont I?
Keron
Im building a DRB GT40#74 .Its not going to be a full on race car ,just occasional track day ,maybe the odd Targa Rally.
The thing is i put a low bid on one on Ebay and won it,now im wondering what im going to do with it, I liked the idea its self bleeding.
Id have to run return lines from the callipers to the circulator or resivour wont I?
Keron
