Big Brake Ducting

[G Cutty]

Hello All,

For my 1987 Oldsmobile 442, I recently did the blazer spindle and corvette brake swap. And I noticed you lose the blazer backing plate when you go to the larger corvette brakes, the adaptor kit supplies shims to make up this distance. Instead of using those shims I decided to build a plate to run 3in brake ducting.

I first started with one of the shims to take measurements off of it to created a bracket in fusion 360. The bracket was then sent to sendcutsend to be laser cut. I used a 3in steel exhaust pipe to make the ducting inlet and welded it to the bracket.

The ducting bracket is bolted between the steering knuckle and hub, I’m waiting on the ducting to arrive, I also fabbed up a ducting inlet and waiting for its delivery.

 

[Tony1968]

Great idea 💡!!!

 

[Built6spdMCSS]

Do you road race the car?

 

[69hurstolds]

Why is this needed? Just wondering. Brake ducts aren’t usually needed on street cars that aren’t set up for road racing where heavy braking is expected. It can’t hurt but it seems unnecessary on what appears to be a stock-ish suspension. Your dime and time but was simply wondering.

 

[Supercharged111]

Not to shjt in your Cheerios, but that is totally unnecessary for a car that isn't used in a way that can cook the brakes. Also, the duct needs to dump the air into the rotor hat to be functional, onto the rotor face doesn't do anything. It hurts absolutely nothing to toss the backing plate, in and of itself this will allow the brakes to run cooler as it exposes the hat to ambient airflow.

 

[Built6spdMCSS]

Yea that's what I was going to toss in as well, if you're not getting air into the fins of the rotor it's pointless. That's where the heat transfer is.

Cooling that one side compared to the other might cause uneven pad wear.

For what it's worth, I swapped on C5Z06 Front Brakes a while ago and have smoked the pads playing on some back roads. Haven't put it on a track for extreme duty, but they've held up fine on street use.

https://gbodyforum.com/threads/c5-z06-front-brake-swap.69342/

 

[nycutlass]

I did the blazer upgrade as well over 5 years ago in my cutlass on a very healthy big block. I never had a need to place air ducting to them or had a bad break pedal after install and I drive my car like I robbed a liquor store.

 

[307 Regal]

My car has never been serious enough to make me start a brake duct project, and I get what's being said about the air not getting into the hat, but you might get a little something out of it anyway since the rotors are drilled. To me it seems like an access point for air. Also I would hope that the rotor would not have uneven heat since it spins. EDIT: Oh, uneven as in the inner face vs the outer face. My bad. Anyway, glad to see race-oriented innovation!

 

[Built6spdMCSS]

Them little holes aren't going to make a difference really. We all applaud the innovation, just no need and if completed needs to be done correctly.

 

[Supercharged111]

My car has never been serious enough to make me start a brake duct project, and I get what's being said about the air not getting into the hat, but you might get a little something out of it anyway since the rotors are drilled. To me it seems like an access point for air. Also I would hope that the rotor would not have uneven heat since it spins. EDIT: Oh, uneven as in the inner face vs the outer face. My bad. Anyway, glad to see race-oriented innovation!

Air does NOT get blown IN through the rotor face on a drilled rotor. Drilled rotors reduce heat dissipating capacity (mass) and give cracks a place to start. With or without ducting, the air is slung from the rotor hat area outward.