Homemade Brake Ducts

[Voltwings]

So my in-laws got me some sheet metal tools for Christmas and i figured i'd bust them out on a fun little DIY project. I know the speed doesnt necessarily "need" brake ducts, and i've survived track weekends without them, but i figure it never hurts to try to keep things as cool as possible.

So design one was just some bent sheet metal and an old intercooler pipe.


The intercooler pipe was nice because it just sat right in there, and i JB welded it to act as a "seal" more so than to be structural. Well, this design had two major flaws. One, i realized that with my sheet metal brake i couldn't do clean bends on two planes... basically once one side was bent, it was impossible to get it back in the brace. The picture is deceiving, there are clean bends here done with the brake, then there are some NASTY ones done by hand (no 90* so the edges dont sit flush). Flaw two was there was no way that intercooler pipe was going to promote flow to the ducts...

Problem number one solved:

I realized a way around the bending in multiple planes was a pretty simple fix. I had some 3/4" MDF laying around and i just cut a shorter brace that allowed me to overlap bends. Nice.



Problem number two solved:

The second thing i found was these whole sale aluminum bezels, $7.50 each shipped was hard to pass on, so i grabbed a set to promote better flow to the ducts.



Just a little grease to act as a template:
(again, the black is JB weld to act as a seam, the ducts are structurally held together with rivets)



Will take some trimming, but thats 100x better:





So this is where i am currently, i'm having to take my time on this project, but figured it was worth posting now in case anyone had some good ideas to help me incorporate them. I currently have the hoses mocked up on the outside of the air guide for the radiator. The very outside edge of the smile is separated from the rest of the smile as far as airflow to the radiator is concerned. My goal here was to capture all that air and direct it towards the brakes (hence, the slightly oversized duct).



This photo was still the first design, but you get the idea:





So here is where i am stumped. The caliper being on the front side of the rotor, as well as FWD, make things very tricky as far as getting proper ducting to the actual rotors. My current plan is just ... remove the dust shields and point it at the hub / rotor as best as possible? I'm debating picking up another set of those bezels and maybe trying to punch it through the dust shield to actually somewhat "pressurize" the air into the rotor like a proper brake duct, but i really have no idea so any help would be appreciated. Thanks guys.

[WAMBUSHHHH!]

@ChaunceyM; - tagging you because I think this was an idea you were toying with?

[Quigs]

I will be looking at doing brake ducts on my track only Gen1 build...I, too, have been puzzled by how to actually get the cooler air to the rotor itself. I'll see if I can spend some time looking everything over in the next few weeks to see if I can come up with something that works. Right now I'm kind of in the same boat where I was just going to rip the dust shields off and just try to blast the back of the rotor with air haha.

[Voltwings]

The Evos just kinda "shoot the gap" between the caliper and hub. Not sure what good that's actually doing, but probably still at least a little better than what we're doing so far haha.

https://www.google.com/search?q=evo+...6GhUpBhRDrM%3A

[Yatta]

Originally Posted by Quigs I will be looking at doing brake ducts on my track only Gen1 build...I, too, have been puzzled by how to actually get the cooler air to the rotor itself. I'll see if I can spend some time looking everything over in the next few weeks to see if I can come up with something that works. Right now I'm kind of in the same boat where I was just going to rip the dust shields off and just try to blast the back of the rotor with air haha.

get one of those aluminum ducts.... cut a hole on the inside of the dust shield, rivet it in and attach flex hose... or... fashion a spoiler that runs to the duct on the shield and have it placed below.. I’ve been thinking about tackling this with some sheet aluminum.

Or, you could do what Porsche did for the 968/951....

http://rennlist.com/forums/944-turbo...-scoops-2.html

[Voltwings]

Realized I got ahead of myself and just kinda spiraled. Took a step back, had some time to think, and realized I just needed to keep it simple. The reason I was fighting so hard to get the duct in this location was because I did not want to interrupt flow to the radiator, but I simply didn't have enough space.

Decided to just scrap the stock "ducting" and make my own to give myself more room, and included a little shelf on it to attach my ducts to. Ditched the actual "duct" I built as well and just kept the bezels. Simple

[Gribbs1469]

Looks good, thanks for the build.

[ChaunceyM]

Nice, this is definitely something I was toying with. But mine were going to be a quality level more along the lines of "We had extra time at a Nator install day and threw some shit together with parts in the garage".
Granted I'm not running enough braking to really need extra cooling. But my budget for further track spending is limited and this was something we could for low money.

Said install day in on May 21-22, so I'll post pictures of our ghetto version soon after

[Voltwings]

Originally Posted by ChaunceyM Nice, this is definitely something I was toying with. But mine were going to be a quality level more along the lines of "We had extra time at a Nator install day and threw some shit together with parts in the garage". Granted I'm not running enough braking to really need extra cooling. But my budget for further track spending is limited and this was something we could for low money. Said install day in on May 21-22, so I'll post pictures of our ghetto version soon after

Lol, looking forward to it. The camera is very flattering to these, maybe i'm just critical but i would have preferred they came out a little cleaner... i need a 3D printer haha, would have really made this nice.

I cant say i really "needed" these either, but i'm incredibly OCD about track prep and this will be our first track day in May (i mean first in real heat) and i'm just being cautious. The nice thing about living in the south is we can track from like October / November through like March / April and we get beautiful weather, which is what we usually do.

Your install is actually going to be the weekend after our track weekend, so i'll be sure to get you any feedback i can. I'm going to hook up my magnahelic gauge and get some pressure readings on the front bumper, inside my little box, and then in the hose down closer to the rotor to see how well the air is actually moving.

[Voltwings]

Well, I believe I have encountered quite a problem. As you will see in the pictures below, my initial measurements were off somewhere, and the duct will not fit as it was originally designed. I realized I can just rotate it 90* and it sits pretty flush on all surfaces, more or less, and gives me plenty of room to mount the hose.





However, when I got out the air compressor and magnahelic gauge, the results did not look promising. As you will see in the video, using about 25-30 psi from a few feet away does create some pressure in the "box," and you can feel a good amount of air out of the bezel. As you move the hose forward however, the pressure becomes less and less, and you feel less and less air coming from the bezel.




^^ That's a video btw, just click on it, I cant figure out how to embed from photobucket.

This leads me to believe one of a few things:

1. The test with the air compressor in no way replicates real world conditions and everything is fine.

2. Positioned as it is, the duct cannot promote flow to the bezel. I was bringing the hose straight at the car, "perpendicular" (disregarding the curvature) to the bumper. I am trying to imagine the car moving through the air as a single wall. However, the curvature of the bumper likely means air will be coming at the duct from the center of the car rather than straight on. I likely need to replicate this test while actually driving.

3. I don't know. I'm just at a loss and after two major set backs this is quite a defeating day, so I just hope someone has some insight. I kind of put the whole project on hold until I hopefully hear back, but I very well may just have to put the car back together and go drive and see.

Tagging yall cuz you're smart. That's what you get for bein smart, you get tagged in peoples threads to fix our shit, kthanks.

@Code Monkey; @Dano; @Ziggo; @phate; @Easter Bunny; @Mauro_Penguin;



So sorry, got ahead of myself. Please ignore this post and see post below.

[Code Monkey]

If you have a laser pyro, I would tape the duct openings over, do let's say 10 hard 80-30 stops and take the rotor temps, then repeat the experiment with the tape removed and see how much cooling you get.

Or you could do it at the TWS, do one session with the ducts open, then another (same or different day but similar weather with the ducts closed), come in on the white flag, and we can take quick temp measurements.

[Voltwings]

Originally Posted by Code Monkey If you have a laser pyro, I would tape the duct openings over, do let's say 10 hard 80-30 stops and take the rotor temps, then repeat the experiment with the tape removed and see how much cooling you get. Or you could do it at the TWS, do one session with the ducts open, then another (same or different day but similar weather with the ducts closed), come in on the white flag, and we can take quick temp measurements.

I'm trying to see if these damn things even work and if I should even bother finishing installing them lol. You're being a little optimistic at this point.

[Code Monkey]

Even if it does not help, it should do no harm, so I would not sweat it too much....

[CorkSport Vincent]

+1 for ingenuity.

[Voltwings]

Originally Posted by CorkSport Vincent +1 for ingenuity.

well no one makes one, and quite frankly my design is still way below my standards, but i'm just getting fed up with it at this point. I wouldn't mind paying someone to make one, hint hint...

[Voltwings]

Did some testing on the way home with this new design.

.5" water @ 30 mph
1" water @ 60 mph
1.5" water @ 75 mph

So we are getting good, high pressure, air. The next challenge will be to get it remotely near the rotor to have any sort of impact. I'll also test the air right at the hose outlet. These corrugated hoses arent supposed to flow for crap, and honestly, looking at the inside i believe it. I wouldnt be surprised if i'm just seeing pressure at the opening because the thing isnt flowing at all.

[Easter Bunny]

The original configuration should also work. If your radiator is sufficiently ducted you will create a high pressure zone in the bumper. This will push air to any low pressure outlet ie the brakes.

[Mauro_Penguin]

I likez your project.

You shouldn't need to worry about radiator flow at all. Those plastic baffle/ducts you replaced with the metal ones do a good job of focusing air into the condenser and radiator below the crash bar. On top of the crash bar there are little ones by the air dams that are attached to the bumper. So really the area you are working in is free to own.

Those flanges you have straight on the bumper are fine. They will capture all the remaining air from the smiley, although it may not seem like a lot. The only way to make them more efficient would be to use a funnel to maximize air capture, which may be difficult given the space constraint.

And for fucks sake don't stress yourself out about it dude. You're doing a great job so far! Remember that you're just aiding heat control over whatever OEM design is already there, as minimal as it may seem. You're not engineering for maximum CFM. Any air flow to the rotor/caliper at all will help drop temps, and that air flow will increase only as speed increases. The cooling effect will be gradual and stable, it won't be a sudden gust of ice air.

How strong is that sheet metal you used as a replacement lower baffle? If it's too hard, maybe consider using the OEM plastic ones and rivet your flange to it. It'll save your condenser in case of low speed crash, like when a moron backs into your smiley bumper in a parking lot.

This is the easy part. The hard part will be securing the duct to the dust shield. There is a lot of stuff going on there by the wheel.

If for some reason you feel unhappy once it's all over, just shoot 50/50 meth at your brakes. Done.

[Voltwings]

i have 20 gauge galvanized steel that i was building the original brake ducts out of. The radiator ducting however i used like 18 gauge aluminum, you could crush it in your hand if you wanted. I used some old vacuum hose and sealed it up real tight against the top / rear / and front, so its stable, but yeah in even a minor fender bender it would be toast.

[ChaunceyM]

Another idea for location: I was planning on taking out the foglights and routing the air from there. Granted I haven't looked too much at all of the obstacles b/t those points, but there's nice round holes in the bumper and the mounting points for the lights themselves should serve as nice mounts for the intake of the brake ducts.
And since I no longer give 2 shits about how the car looks, I have no problem tearing out the fogs.

It's possible that airflow there wouldn't be great at speed given the geometry of the bumper, but it seemed like an easy place to start.

[aackthpt]

Originally Posted by ChaunceyM It's possible that airflow there wouldn't be great at speed given the geometry of the bumper, but it seemed like an easy place to start.

I bet it works well. That's exactly how the ducts from Flyin' Miata work, they all mount in place of the fog lamp / driving light / whatever you like to call it.

[Voltwings]

Originally Posted by ChaunceyM Another idea for location: I was planning on taking out the foglights and routing the air from there. Granted I haven't looked too much at all of the obstacles b/t those points, but there's nice round holes in the bumper and the mounting points for the lights themselves should serve as nice mounts for the intake of the brake ducts. And since I no longer give 2 shits about how the car looks, I have no problem tearing out the fogs. It's possible that airflow there wouldn't be great at speed given the geometry of the bumper, but it seemed like an easy place to start.

On my mustang,

getting air from the front of car: easy as hell
getting air to the brake rotors: easy as hell
everything in the middle: Giant cuss fest designed by satan himself.

On the speed,
getting air from the front of the car: hard, not impossible
getting air to the rotor: challenging...
everything in the middle: piece of cake. Got room for days up under there, and its a straight shot back with nothing in the way.

[Tomas]

You are overthinking this.

MS3 Brake Ducts

[Voltwings]

Story of my life

[ChaunceyM]

Originally Posted by Tomas You are overthinking this. MS3 Brake Ducts

Show off.

[ChaunceyM]

Okay, so I need to stop joking about this and actually do it. Boiled fluid again during a 70F day and only running about 75% since it was event #1 . Caliper bodies were almost 500F in the pits after a post-boil lap (obviously this happens immediately after the entrance to the pits) and coast across the paddock. Castrol SRF will definitely go in before the next event, but so will at least basic ducts.

"Conveniently" I got yet another hold in a CV boot, so the car is about to be up on stands for at least a day while I deal with that. While it's up in the air I'll pop out the fog lights and run hoses pointed back through the rims.

As for theory on cooling, where do I want the air directed? Right onto the rotors since that's where the heat's being generated? Or more at the caliper bodies since that's where the fluid is actually boiling? I may not get quite that sophisticated, but just in case I want to know how it should work.

[Easter Bunny]

you want the hose to be pointed at the center back of the rotor. if you look you will see that that is where the cooling air enters the vanes.

[ChaunceyM]

Thanks for confirming. That's what it appeared to be, but I wasn't sure if there were nuances I was missing. Like directing some towards to the calipers themselves or something like that.

I've reached out to my buddy who works in truck suspension to see if he knows someone who can help me fab up something. If I can avoid half-assing the outlet that attaches to the rotor I'd love to.

[SIXual Panda]

if you are going for full function, why wouldnt you just take your fog lights out and use that hole to make your inlet, and just route like flexible dryer ducting to wherever you need to go?
that would hands down be the easiest way to go about doing it.
EDIT: yeah... kinda like tomas did a few post up. hahaa

Im planning on eventually fabing up something to fill the entire fog light shroud/housing on my speed6 that funnels down into like a 2.5 or 3" circle, and run it to my brakes.

[ChaunceyM]

Yeah, that's been my plan all along. I'd just prefer to have something nice for the outlet. Not only to get more efficient airflow to where I want it, but also because I don't want shit unraveling or coming loose at the track.
If I can't have something fab'ed by the next track day it'll just have to be an open hose as close to the rotor as I'm comfortable with and a shit-ton of zip ties.

[Voltwings]

The fog lights will work, and they will likely work "fine." However, pulling from the high(er) pressure area in the grille would be preferred to the fog lights, as they are more outboard on the bumper and cannot supply as high of pressure to the ducts.

[SIXual Panda]

Originally Posted by Voltwings The fog lights will work, and they will likely work "fine." However, pulling from the high(er) pressure area in the grille would be preferred to the fog lights, as they are more outboard on the bumper and cannot supply as high of pressure to the ducts.

Genuine question, Why would the inner/center grill area be a high pressure area, and not the foglight shrouds?

is it just because of the square footage of the grill area? or is is because of it being in the center of the car and thats the first thing that the air would hit when you are driving?

[Voltwings]

Originally Posted by SIXual Panda Genuine question, Why would the inner/center grill area be a high pressure area, and not the foglight shrouds? is it just because of the square footage of the grill area? or is is because of it being in the center of the car and thats the first thing that the air would hit when you are driving?

i'll try to describe this as best i can. Let's say you're standing directly over the car and looking straight down at the front bumper (so through the hood, down to the ground). Let's say we lay a 2D plane into our viewing area, with Y being straight towards the back of the car, and X being to either your left or right.

The front of the car is receiving almost all air perpendicular to the X plane correct? Its a flat surface that allows air pressure to build. As you move outboard however, the car starts to get more and more Y direction and the air does not have a chance to "stop" and build pressure. The air is also moving outboard and is not going to want to make a turn into a brake duct located in the foglights. Located in the grille, the air is moving straight into the duct with very little fuss.

Like i said, it is probably being nit picky, but the concept remains the same.

[SIXual Panda]

Originally Posted by Voltwings i'll try to describe this as best i can. Let's say you're standing directly over the car and looking straight down at the front bumper (so through the hood, down to the ground). Let's say we lay a 2D plane into our viewing area, with Y being straight towards the back of the car, and X being to either your left or right. The front of the car is receiving almost all air perpendicular to the X plane correct? Its a flat surface that allows air pressure to build. As you move outboard however, the car starts to get more and more Y direction and the air does not have a chance to "stop" and build pressure. The air is also moving outboard and is not going to want to make a turn into a brake duct located in the foglights. Located in the grille, the air is moving straight into the duct with very little fuss. Like i said, it is probably being nit picky, but the concept remains the same.

Yep, that does make sense. Thanks for explaining.

[ChaunceyM]

Originally Posted by Voltwings The front of the car is receiving almost all air perpendicular to the X plane correct? Its a flat surface that allows air pressure to build. As you move outboard however, the car starts to get more and more Y direction and the air does not have a chance to "stop" and build pressure. The air is also moving outboard and is not going to want to make a turn into a brake duct located in the foglights. Located in the grille, the air is moving straight into the duct with very little fuss.

Yeah, the more I read on theory the more I want to move the inlets towards the center. I might try to put little vertical "wings" the outside ends of the fog light opening to re-direct air into the tubes since it will be trying to go sideways over the inlets. Or just hack my way to the middle of the grill and call it a day.
Although if I can get sufficient cooling of my setup from fog-mounted inlets I'd probably just leave it until I see a temperature problem reappear.