ZLE Brake Ducts???
 

Okay folks, I think I'm going to need some increased cooling on the back side of my rotors....

I had a very close call at RoadAmerica the weekend of the 4th.

I knew my AP Racing Brake J-hook rotors were getting close to needing replaced. Heat checked fairly badly (RA is incredibly hard on brakes) and I was looking them over closely before every session.

Nothing I could get a fingernail to catch on, nothing too severe on the outer edges of the rings. Was about to go out for my next session and decided just before suiting up to flip my front tires side to side (RA is also hard on the outside edge of the drivers front tire) to see if I could get a few more sessions out of the Michelin slicks.

With the wheels off I had a chance to take a better look at the rotors and this is what the BACKSIDE of the front rotors looked like.

In a word, that next session could have been catastrophic.

So, learned a valuable lesson about making sure I am checking both sides of the rotors - and - it is clear that I could use some more cooling on the inside.

Unfortunately, the Garage Therapy ducts are no longer available. Anyone have a different alternative to get some direct ducting into the back of the rotors on a ZLE??

Thanks for any input.

What are you running now, just the stock ZLE ducts? I've been using the SS Track ducts which are larger and get additional air from under the car

i have a set of brand new never used garage therapy ducts if youre interested pm me

I’m also interested in this, also had a close call at the track today, I’m thinking something custom from my mechanic if there are no keys out there

PM sent!

Yep....just the stock ZLE deflectors on the control arm. Those SS defectors certainly do look more effective. But....I'm hoping Ichabod can hook me up with the GT kit.

I'm REALLY hard on my brakes. Turns 1 and 5 at RA is where I catch a lot of guys.....:D

Thanks!

I had the GT ducts and switched to these. Kept wearing thru the hose but you may have better luck.

https://www.gmpartsgiant.com/parts/g...-84145204.html

FYI - while I like the idea of the Garage Therapy ducts, the 3D printed duct has a smaller cross-sectional area than the stock plastic duct. Returned them.

Has anyone ever seen a stock ZL1 rotor crack that deep and bad? Maybe one has, I just haven't seen it posted.

Were you running 18" wheels? You have a lot less brake cooling with the 18's. You have the 372mm AP or 390mm kit?

There's not a lot of room with wide wheels / tires during sharp turns. The outboard coolers mean not a lot of room for the brake ducting.

Like Mike (carguy55) said, the regular SS 1LE track deflectors work decently - dropped my front caliper temps by ~50F. They hang low especially on a ZL1 1LE, but, are dirt cheap. PN 84433357.

Great information here, I can totally see how those 84433357 ducts improve the brake cooling. Is the 84433357 a kit, i.e. when ordered it includes left and right?

Yes and it comes with the smaller ZL1 / J6H rotor heat shields if you don’t already have ZL1 brakes.

18's and 372mm.

I may end up experimenting with both solutions.

Thanks for the input.

Was the wear from wheel/tire contact with the hose?? Or something else?? Thanks.

Hose was his issue with the rubbing not the FLCA deflectors.

The rotor wore deeper closer to the hub. If you look at the J in the rotor there visible on the outer part of the ring but not the inner. The lip on the outer to the inner also shows this.



I used to slot rotors for people back in the day I would always cut the slot to the min. rotor thickness so if it was worn smooth your rotor was done. The few bought ones I checked the groove was always way deeper. Powerslot was the one name I remember.