Airdam/Rad Duct/Brake Duct Tested
 

After doing my airdam, radiator ducting, and brake ducting via naca ducts on the sides of the rad ducting, I may be moving the brake ducting inlets to the airdam...

Testing was done with a 3inch magnehelic gauge:

Pressures taken at 40/60mph:

Front of the airdam - .6/1.8

Inside rad duct, on bottom right in front of the rad - .4/1.0

Engine side of the rad - .1/.25

Pass side brake naca duct - .3/.6

Pass side brake duct outlet - .0/.1

Driver side brake naca duct - .25/.55

Driver side brake duct outlet - .05/.1
https://cimg7.ibsrv.net/gimg/www.mia...cd153f0100.jpg
https://cimg8.ibsrv.net/gimg/www.mia...818aad5e46.jpg
https://cimg0.ibsrv.net/gimg/www.mia...5b14e8a9ee.jpg

looks nice

My question is, did the rad duct inlet provide enough cooling to be functional? What pressure differential is required to give functional cooling? If the rad duct inlet still provides the cooling required to keep pads happy, wouldn't it still be better to retain that?

I guess what this boils down to is what the 2D graph of pressure differential vs duct flow looks like.

It wasn't enough to keep the G-Loc R10's cool at Blackhawk Farms Raceway during a sprint race.

Granted BHF is really hard on brakes...


What we're seeing is a large restriction inside the ducting itself. likely due to the typical miata turn that happens in order to clear the wheels... increasing the incoming pressure is the easy button to getting more flow through it.

Have you tried taping off the duct and recording pressures in the same exit location?

we did some testing on our quarter window naca duct yesterday and that's going to lead us to doing something similar this evening. we're going to cap off the brake naca duct exit, and measure the pressure in the naca duct.

this should tell us not just the direction of flow and restriction in the brake ducting itself, but the amount of flow.

so we've learned a few things i wanted to write down for record:

we should've put the protective mesh right in front of the rad, where the incoming air is slowing down and would create less of a restriction.
we should try to put the brake duct inlets farther towards the airdam, before the air begins to slow down (thus reducing pressure). but unable to do this due to the size of the naca ducts and bumper beam.