More fun with brakes

At CMP, still had some brake cooling issues. Boiled my Super Blue one session  and had some pad fade on the next one.

I think several things contributed:

  • I didn’t do a fluid bleed after my last track event… probably wasn’t as fresh as it should be.
  • I was trying to get all the use I could out of an old set of Carbotech XP10’s… ran them down to 3-4mm. Thin pads transfer MUCH more heat to the pistons and fluid
  • The duct config wasn’t as effective at delivering air to the rotor bowl as it could be
  • After boiling the fluid, I drove like a newb the next session and drug the brakes far too much because I didn’t trust them
  • And it was 100F in the shade that day, on the toughest track on brakes that I run, with lots of high speed heavy braking and little cool down time.

Anyway, I’ve made some changes, hopefully to ensure no more of this brake foolishness.

Reworked the brake ducts, for much better air delivery to the rotor bowl.

The key component of this was the 6″ long 2.5″ aluminum joiner tube, from Amazon https://amzn.com/B014GXQI16

I cut this in half, and flattened the open end of each half.
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Click the image to open in full size.

Then cut a length of 1″ wide galvanized steel, ground it with a die grinder to fit around the wheel bearing assembly, and drilled to bolt it to the factory rotor shield holes. Bent to shape, drilled and bolted to the 2.5″ tube segment as shown.

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Click the image to open in full size.
Click the image to open in full size.
Click the image to open in full size.
Click the image to open in full size.

That should do it. Uses low-temp hose for most of the duct, only uses the high-temp silicone hose for the last 9″ or so near the rotors. You can “screw” together segments of this hose, then secure it with racer tape.

Also got a set of titanium brake pad shims from TCE (slip between the pads and pistons, and reduce heat transfer into the Pistons and fluid), and a liter of Castrol SRF fluid. Did a full brake and clutch flush with the SRF, including ABS bleed. We’ll see how the SRF holds up for the rest of this track season. Many folks report that they don’t need frequent bleeds when using SRF, since it has such a high wet boiling point.
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Moar Coolness

It gets kinda hot at the track, when it’s 100F in the shade.

So I bought a 13qt CoolShirt system. Installed it today.

Instead of the $220 Cool Shirt flow controller, I used a simple PWM speed controller from Amazon… $12. Yes, $12 instead of $220. Does EXACTLY the same thing. Simple wiring. Switched power (from an add-a-circuit in the footwell fusebox) and ground in, and two wires out to the CoolShirt pump.

Mounted it under the center stack, where I can reach it, while harnessed in. Clicks on/off, and one turn to full flow. Easy to trim the flow as desired once you’ve cooled down. Running it at less than full flow extends the runtime on one fill of ice packs and water. Should get a full day of track sessions (~2hrs on the track), plus some time in the paddock.

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Cooler goes in the rear, straps down using the cabrio tie-down points. Added quick connects on the wiring so it’s easy to pull out. All the hoses come with quick connects that don’t drain when unhooked. Just a few drips of water, no big deal.

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Filled it with some cold packs from the freezer, topped of with water, and sealed it up. Put on the shirt, hooked up the hoses, and switched it on.

I’m water cooled!

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I’m leaving the 12′ hoses and the shirt hoses at full length, for maximum flexibility. At the track, I can pull the system out of the car in 2 minutes and run it off a spare battery for cooling while sitting in the paddock! I’ll wire up a separate power harness for that.

I bought the system from Linda at Apex Performance. They’re fantastic folks, and if you call her she can hook you up with a great price.
Mine is the 12/13qt “Club” System.

Here’s the speed controller switch I used.

Looks like a giant CPU cooler, but isn’t

Insane GP Roadster Project of the weekend:
Remote oil cooler.

There won’t be room up front for a typical cooler when my monstrous front-mount Intercooler is installed (with the new TVS supercharger). So had to improvise. Found a nice Derale packaged unit with twin puller fans (Model 15845), that I could mount on the rear deck. Some lucky hose routing, drilled a couple of holes, and it all just came together. RMW oil cooler adapter plate, -10 AN hose and fittings, 190F thermostat for the fans.

Stock cooler, hoses removed. Looped back one coolant hose and secured with a hose clamp.
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RMW adapter plate installed, with -10 AN fittings (-8 AN ORB into the plate) and longer M6 bolts. Be sure to use fresh seals behind the plate!
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-10 AN hose, cuts like buttah with large Harbor Freight cable / hose cutters ($20). Use the polyester sheath hose, NOT the hose with the stainless sheath. Because if that stainless hose touches anything, it acts like a cheese grater, very quickly.
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Installed 90deg ends and attached hoses. Since I’m going to the rear of the car, best routing for me was down the right side seam. Gets there between the tie rod boot and swaybar. Yes, there’s clearance… Barely.
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To the seam. There just happens to be an indentation in the floor pan there that is perfect for the hose to nest into.
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Took a while to decide on optimal routing into the rear compartment. Many times up and down on the lift, finally found a spot that would clear everything and be close to the corner. Held important stuff out of the way above and below, and carefully drilled holes.
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Click the image to open in full size.
Click the image to open in full size.

Use grommets so the body doesn’t cut the hose!
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Measure, mark and cut hole in plywood deck. Taped it first, to protect the vinyl.
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Pretty it up!
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Mount the cooler.
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Attach ends and hoses, and wire it up! Switched power to the thermostat, then to the fans, 7.5A.
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Tidy up all the wiring and hoses.
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Replace the underbody panel, working the hoses into their final position, on top of the edge of the panel and up against the body seam, out of harm’s way. Nothing exposed underneath.
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Worked in the garage test, fans cycle on and off as they should, no leaks. The fans exhaust an impressive amount of hot air when running. Will road test it today.