Brake Ducts
 

Because I'm not creative enough.

After searching for a while, I'm not content with what I found.

I used to have brake ducts like this
https://fbcdn-sphotos-a.akamaihd.net...39_21150_n.jpg

They weren't attached to the spindle, only aimed at it, but I'm pretty sure they still made a difference. I'm on 1.8 brakes with HP+ (I know these aren't track pads, now with boost I'm probably going to try out some XP10's or 12's), and I would fade badly before I put these ducts on. It is possible that its just placebo. I didn't attach them because they would get squeezed at full lock and I still DD the car. I am way too lazy to take them off/put them back on at every track day.

Now, there is an intercooler in the way, and I can't see any possible way to fit those hoses around it and the piping. However, I have an r pkg lip with those "ducts" built in. Heres the problem, which I'm sure those who have tried this know about:
Exhibit A
https://www.miataturbo.net/attachmen...ine=1312142340
Exhibit B
https://www.miataturbo.net/attachmen...ine=1312142273
Round hose, not round hole. I tried to fit the hose inside the duct and that looks shitty and I can't see it working that well. That would be my last resort. Theres no way to get the hose around the duct so thats out too. Does anyone have any ideas? I'm not sure if just better pads will hold up at the track (I'm on street tires-RE11's), so these ducts would inspire some confidence.

I saw this in another thread, but I have no idea how he did it.
https://www.miataturbo.net/attachmen...6&d=1268810788

Also, general brake ducting thread.

Check hustler's build thread, he fiberglassed circles onto his lip to clamp the hose to.

I see. Time to PM him with stupid questions.

For mine I am going to try making the transition piece (OEM lip to round brake hose) out of kydex, which is a thermoplastic commonly used for gun holsters among other things. You can buy small sheets of it off the web. Heat it up with a heat gun and shape it how you want. I've never worked with it before but it seems doable enough.

If that doesn't work, I have a pair of small naca ducts that I bought from Pegasus because they were cheap enough. These will be Plan B though, because even the "small" naca ducts take up quite a bit of real estate in the nose of a Miata and I don't want to hack it up that much unless I really have to.

Hustler shared some ideas with me about NACA ducts, I THINK I am understanding his idea correctly. I don't believe they involve hacking up the bumper. I will try some drawings on MS paint and post them here to see if they really are what hes talking about.

Also consider the lower a-arm mounted air directing vanes German cars put to good use.

https://www.miataturbo.net/attachmen...ine=1312216195

I used 4 of these
http://www.racerpartswholesale.com/p...43/Naca_Ducts2

with carful use of heat and some cutting I was able to reshape them to fit the shape of the GV lip openings well enough. And use some black silicon to seal it a bit with pop rivets to hold them to the lip.

For single ducts you might try this
http://www.racerpartswholesale.com/p...47/Naca_Ducts2

It will take some creativity.

Bob

Just get high temp duct hose with "finished ends" from McMaster Carr or your local hose & tubing supplier.

http://www.mcmaster.com/#hose-duct/=dfkkjc

No wire in the ends, they're glued on cuffs. Cut a couple of slits to fit over the stapled seams on the factory ducts and screw or pop rivet on.

After cooking fresh Motul brake fluid at Pacific Grand Prix (Kart Track, great for Miatas), I decided I need some brake cooling. I didn't want to spend big $$$ so I went with cheap rubber hose instead of the expensive silicone stuff. I figured that when the hose doesn't actually touch the backing plate but ends an inch or two away from it, the temps should be much lower. I verified that it actually works, I installed the ducting on the driver sides and did some back-to-back 60-0 stops and measured rotor temps, 380F on the passenger side and only 230F on the driver side.

http://s1.postimage.org/igicwfd1z/Mi..._cooling_1.jpg

I also ran into the problem on how to fit the hose on the odd-shaped opening on the fron lip and decided to not use it but use some generic intake duct instead. I ordered the ButlerBuilt Headlight Mount Ducts and the hose from pitstopusa for a grand total of $60. Cutting openings in the bumper seems a bit extreme, but it actually looks pretty good and works great.

http://s1.postimage.org/igiyeevh3/Mi..._cooling_3.jpg

The 3" hose is probably bigger than it needs to be, 2.5" wold probably be enough.
It's tight on the inside of the wheel (6UL in 15x8 with R-S3s in 225/45-15) with the intercooler piping but it all fits with no rubbing even at full lock.

http://s1.postimage.org/igirs9hhz/Mi..._cooling_2.jpg

Bob, were the oil cooler ducts necessary? Did you run it without the ducts before and have temp issues?

I dont even think bob has an oil temp gauge. Atleast I dont remember seeing one last time I was in it.

Our A-arms have flat fronts, and the tie rods are in front of them anyway, so this would be totally useless.

I know the suspension, I have a Miata.

Perhaps I should submit a picture of such a deflector on a Miata.

Hint. You go lower. The concept is to catch some air and redirect it to the area desired. Nice ducting is better though.

Brightened image a bit. BTW, if the entry received some attention, the airflow could be increased if that was desired.

The problem is any off track excursion (or even just hitting berms) would likely destroy them if they hang down any significant amount.... especially considering I have scrape marks on the bottom of my control arms.

Yes, good point. To some extent the suspension lifts out of the way, the outboard end. Deflector material can be something flexible which can help.

If you are scraping under your a-arms, how has the car's underside and front air dam (likely lowered) been doing?

Beat up for sure. Frame rails are the worst (blue and red are common curb colors to see on them).

Oh, and the EOC location is definitely not somewhere I would ever put it. Too vulnerable in that spot and no pressure differential across it.

They are totally required. I had 275*f temps until I re-worked my ducting. Now it's 230*f in the summer.

+1 I routinely scrape my frame rails just going over speed bumps around town.
And I cracked my r pkg lip at some point. :vash:

What oil cooler are you using? I vaguely remember reading that some people with the rx7 oil coolers just stick them above the intercooler and never have oil temp problems on track. Doesn't even see direct airflow IIRC.