Cyclon36

After seeing the advantages of having brake ducts for track days, I definitely want to get a setup going. However, I have a problem. I'm running an Injen CAI and routing from the fake vents is not possible since the filter is in the way.

Instead of using a ram air type brake duct system, I figure I can route a NACA style duct facing down on the under tray of my car just ahead of the wheel underneath the bumper. The NACA intake is like the one pictured below:



It won't get the blast of air that the ram style does on the front, but it should be functional and I won't need as much ducting to take it to the wheel and installation can be done without taking the front bumper off. Also, I could probably install a small scoop over the opening that could channel air into it making it more efficient.

Has anybody tried this sort of duct or placed theirs in a similar area. This way I atleast wouldn't have to chop my bumper up either.


BTW, does anybody know the best place to get the hoses and the mounting plates that connect it to the brake dust sheild?

SC_Highlander

I got my aluminum flanges from http://www.aircraftspruce.com/catalog/appa...ductflanges.php

I used 2.5 inch flanges and got the 2.5in silicon tubing from racerpartswholesale.com. You will run into very tight space problems on the driver's side due to the air pump -- especially if you are drawing air from the undertray. On the passenger's side, I think there is enough room for both the CAI and the ducts, but it would be tight. You may be better off mounting an intake at the bottom of the radiator grill.

mikegarrison

I bought my hoses and flanges from Wick's Aircraft supply. I recommend buying from an aircraft shop rather than a race shop for reasons of both price and variety of choice.

Having done 3-inch hose on my own car, I would recommend no bigger than 2.5-inch. 3-inch was a real routing problem.

As for the NACA inlets, those are designed for areas of laminar airflow along a flat surface. I would advise against adding a "small scoop to channel air into them". They are shaped the way they are for a reason, and unless you are careful you will cause problems rather than help things. If you are going to install a scoop of any kind, then just go ahead and install a scoop duct that feeds right into the hose, and skip using the NACA inlets. I guess it all depends on how much ground clearance you are willing to give up.

I would also consider sticking scoops into the main grill area (where the radiator is) and finding a ducting path from there.

Sideways

This may fit the ticket. The total weight is reduced by eliminating the steel dust shield and replacing it with a composite. The air is directed to the rotor with a nozzle. The CF scoops have withstood the test of time on my stock height car.

Cyclon36

Ok, so adding a scoop might compromise their design. How about just leaving them the way they are and mounting them on the bottom like I mentioned before? Is there enough laminar air flow below the front bumper to be useful?


Sideways, that's an interesting setup and similar to what I wanted to do in a way. I think it's a little too permanent for me as I would destroy the scoops during every day driving. Did you make those carbon fiber peices yourself?

Cyclon36

I found the flanges on Wick's site. Definitely a better selection than at the racers site. However, they offer several different types of hoses. They range in temp values from 350F max to 500F max. Do I need the 500F or is the 350F fine b/c the price difference is double?

mikegarrison

I bought the orange SCAT hose. Yeah, it's twice the price but that's still only a $30 difference. BFD. But I expect the CAT hose would probably do OK.

I don't know what the pressure profiles are really like on the underside of the bumper. My guess is that you will pick up air using those flush-mount NACA inlets, but not as much as if you used some sort of scoop.

But I don't really know. It would be kind of cool to use some pressure taps and manometers to actually measure the pressures, but I've never bothered.

Cyclon36

I went ahead and bought the CAT hose sine it was black. I think it will not be as noticable and I doubt it will see 350F anyway. I got the better deal on racerpartswholesale on the hose and the ducts, but I got the flanges from Wick's. Those will definitely let me have a clean install.

I know this won't be as effective as the front mounted scoops, but I think it will work well just the same. I'll make up some scoops for the ducts and try running the track with and without them to see if there's a difference. I'll update this thread with pictures sometime next week when everything should be in.

freq

Cyclon36

Hmmm, all those high dollar mods under the car and you use aluminum dryer ducts for the brakes?

BTW, it looks good

Do the rear ducts help out alot or did you just do them to do them? I'm sure they work fine, but I didn't think the rear brakes got that hot.