VanSpeed

OK folks here are some pictures of the spindle ducts I made for 1985 C4. Now I may have an advantage over those of you with the later model C4’s. That is the early C4’s had dust shields on the front brakes so there are 3 bosses on the knuckle that the dust shield attached to. These may not be on the later C4’s so attachment would likely have to be via the hub bolts-at least that is what I would try.

I used the old dust shield and cut a hole in it for the 3” tube. I fabricated from .030”T aluminum the 3” tube that the hose is attached to. As you can see the tube is held to the old dust shield with pop rivets. I had a different spindle duct that was made from approx. .080”T aluminum with only a 2” diameter tube. As the car got faster I needed more air so I made the set up you see in the pictures below. Well see how it works later in the summer when I am able to get back to the track.







Brian

mothersworry

BrianCunningham what size are the ducts on the mid america kit? Seems like the easy way to go.

Slalom4me

Thanks for the pictures and details.

Ken R.

BrianCunningham

from memory, my car's in storage accross the country, 2in kind a small

rickneworleansla

Good thread here. I was about to buy the mid america kit. Now I'm thinking of adding my own to my already worn out spoiler. I won't feel as bad as if I was to mess up a new one. I was wondering why no one tried plastic tubing like a vacum hose. Is it not flexible enough for the wheel travel? It seems from the pictures that one hose to the caliper and one to the rotor is the way to go. Where did the plastic molded intakes on the spoiler come from? Thanks for the great ideas.

larryfs

I have been pretty sucessful with the cheesy kit from mid america.
No boiling, no fade, and my rotors last many events. The tubing is smallish, but it seems ok.
I now have it pointed at the center so the air goes inside the veins of the rotor.

early on, I had it pointed to the inside rotor face, and that worked great for the inside face of the rotor, but did nothing for the outside. so I made some changes.

Slalom4me

On a current 84-90 Mid America spoiler, the ducts have 2-1/2"
hose outlets. I think it is well made.



Note that there is more than sufficient lip for hose attachment with
rivets or speed nuts.



Mid America includes two sections of tubing - enough for me to cut
two pairs of duct hoses. The hose is some sort of molded 'plastic', not
the wire reinforced fabric or silicon type. IMO, they'll be good long
enough for the tires to rub through them and then they'll be replaced.

.

ZR1 MK

I have updated to a dual intake scoop for this year with the second duct going to the caliper. Caliper and rotor temps are reduced. Heres some pics of my duct work. Notice how the pipe is oval shaped so all cooling air is forced in the rotor and not on the rotor surface.

96GS#007

That's a heck of a nice setup

What did you use for the scoop?

What size are the hoses?

Sidney004

That is a heck of a nice setup. When do you decide to manufacture these, you have your first customer.

ZR1 MK

The scoop is a stadard Butler unit. It was heated with a heat gun to conform to the spoiler curve. All 4 ducts are 3 inch.

ZR1 MK

If I only had the time.

AUTO_X_AL

From what I understand cooling the actual calipers is the ticket to consistant brakes. The rotor will be able to dissapate heat better than the caliper can. I use the mid america kit using 3in ducting pointed at the caliper itself. The doug rippie stainless pistons also help on the GS brakes to transfer much less heat to the fluid. With two drivers we have yet to have any issue with the setup. Just my $0.02

ZR1 MK

I installed ss pistons (when I had stock calipers) and 3 inch ducts to my rotors before I did any track events. I wouldnt consider running without either. Rotors need airflow.
My Wilwoods are far superior than stock, so I was never concerned about ducting them, but I do have a better set-up now that I added caliper ducts. Taking and recording temps at the rotors and calipers tell the story.

AUTO_X_AL

On Danny Kellermeyer's TCC car I watched temps climb up almost 1300 degrees at gingerman. The heat does not accumulate when you are on the brakes it is the 2-3 seconds after you let off and the heat soak gets them hot. He runs stock C5 crakes with hawk pads and has no issues. He advised us to keep the caliper's cool. That being said it will also cool the rotors to some degree. I was just advised to pay more attention to the calipers than I had previous. Believe me I agree with what you said but I think that cooling the caliper is a sound Idea as well. With good cooling the brakes can cool very quickly as I witnessed in Danny's car the temps were going from 1250 degrees down to 750-800 in the short front straight after turn 11 at gingerman. It was crazy to watch the temps on the pyrometer slowly climb after he exited the turn and within a few seconds drop like a rock 400-500 degrees! With good cooling of course!

AUTO_X_AL

When I mean watching the pyrometer I mean watching it in the car doing hotlaps. Brake temps change dramatically in little time so it was very cool watching it happen in real time.

ZR1 MK

What system are you using? I use rotor paint, caliper tape and the infared gun. All my temps are pit readings.

AUTO_X_AL

we used a gun in the pits and after a cool down lap I was about 700 degrees so we estimated between 1100 and 1200 on track at waterford. Danny has a thermal coupel on the caliper's themself and has the pyrometer in the car for real time data. at gingerman I think it held the high temp around 1300 give or take. There is a huge diffrence between pit temps and real time on track temps. It varies alot between the two. I never would have thought it was that dramatic had I not seen it for myself.

ZR1 MK

There are differences in temps between all the variables. My main goal is to take temps after a similar last lap to compare any mechanical changes made to the car, compare results of different air temps or compare the different levels I push the car.
I would like to have a real time data system. Thats the ultimate.

AUTO_X_AL

Consistency is the key as always but Danny's got some cool stuff and he is awesome as far as vette tech goes. Not to mention he is a hell of a driver. If you can attend any of the schools he puts on for the high speed series you will walk away knowing much more than you did prior to attending. He's helped us out on many occasions with the car and helping to correct driver errors as well.