$200 brake ducts for all four corners

[3MOS]

Appreciate the video FlyingLow! Maybe I'm confused as to the view/what's being shown, but it almost looks like you removed the heat shield completely. Is that the case? (I think that's recommended for some of the big brake kits)

If not, I'm curious whether removing the heat shield (or at least putting a few larger holes through it) would be better than the other options for ducting/routing air through a single hole in the heat shield. I realize you wouldn't have a stream of cool air directed to the caliper/rotor, but it seems like there would be decent air flow all around the rotor and caliper nonetheless.

[FlyingLow78]

Originally Posted by Redline10000

Nice I may need to look at that for my rear setup.

They’re a super cheap solution for direct caliper cooling with almost no modification. You just need to drill a few holes for the cable ties to secure it to the lower arm.

Originally Posted by 3MOS

Appreciate the video FlyingLow! Maybe I'm confused as to the view/what's being shown, but it almost looks like you removed the heat shield completely. Is that the case? (I think that's recommended for some of the big brake kits)

If not, I'm curious whether removing the heat shield (or at least putting a few larger holes through it) would be better than the other options for ducting/routing air through a single hole in the heat shield. I realize you wouldn't have a stream of cool air directed to the caliper/rotor, but it seems like there would be decent air flow all around the rotor and caliper nonetheless.

You’ve tapped into some of my thought process when I decided what to do with it. Essex says to remove it altogether, but then I’m relying on high entropy air for cooling. With the full shield in place it blocks a lot of airflow to the rotor. I wanted a focused airstream on just the center of the rotor for heavy braking tracks like Monza, so my compromise was to attach a 2.5” aluminum flange to the shield and cut everything else away (except what was covering the rotor hat and the three mounting points). The ideal solution for me would be something like the M4 GT4 carbon fiber rotor shields, but I’m not paying $1400.

I’m in Spain at the moment and will be driving on Circuit de Catalunya tomorrow. There are two heavy braking zones per lap and I’ll update this thread if there’s anything noteworthy, otherwise just keep an eye out for my post in the track sub forum early next week. I’ve got eight cameras on the car now and hope to provide two different views of the front brakes in action. I’ll be running the full ducts again after leaving them off the car for a wet Mugello. I also relocated the calipers temperature strips and added a second strip to each of the fronts to try to more accurately capture temperatures near the pistons.

[FlyingLow78]

Ok, something noteworthy happened. I accidentally broke the left front 3D-printed scoop, so that brake only had ambient cooling today. It still didn’t pop any of the temperature strips, and the lowest gauge is 370 degrees F. It did, however, consume far more brake pad material compared to the right front. The rotor acted like a huge heat sink and the whole wheel arch was seriously hot, even after two gentle cooling laps, whereas the right was actually cold by comparison.

You can run without cooling, but I highly recommend having it!

[drroc]

Originally Posted by FlyingLow78

Ok, something noteworthy happened. I accidentally broke the left front 3D-printed scoop, so that brake only had ambient cooling today. It still didn’t pop any of the temperature strips, and the lowest gauge is 370 degrees F. It did, however, consume far more brake pad material compared to the right front. The rotor acted like a huge heat sink and the whole wheel arch was seriously hot, even after two gentle cooling laps, whereas the right was actually cold by comparison.

You can run without cooling, but I highly recommend having it!

That is pretty sweet. Where did you get the STL file for the scoop? Any chance that you could share? I've been thinking of mocking up one, but I seem to be quite short on time always

Edit: I found the original STL file https://www.thingiverse.com/thing:3566812 Do you have edited version that solved the rubbing issue?

[FlyingLow78]

Originally Posted by drroc

That is pretty sweet. Where did you get the STL file for the scoop? Any chance that you could share? I've been thinking of mocking up one, but I seem to be quite short on time always

Edit: I found the original STL file https://www.thingiverse.com/thing:3566812 Do you have edited version that solved the rubbing issue?

The file is at work, and needs some tweaking, since the wall thickness was insufficient on the first set we made after editing. I need to order some more plastic, then I'll get with the gurus in the shop to sort it out. The original file is a damn good design, though.

[drroc]

Originally Posted by FlyingLow78

The file is at work, and needs some tweaking, since the wall thickness was insufficient on the first set we made after editing. I need to order some more plastic, then I'll get with the gurus in the shop to sort it out. The original file is a damn good design, though.

What material did you use? Was it PLA? I am thinking of trying to print it with nylon as it should be much more robust in case of an impact.

[FlyingLow78]

Originally Posted by drroc

What material did you use? Was it PLA? I am thinking of trying to print it with nylon as it should be much more robust in case of an impact.

ABS with 100% density for strength.

[HA55L3R]

Originally Posted by FlyingLow78

I have a similar setup on my M3, courtesy of the M2 forums. I added Porsche GT3 front scoops to the rear arms to direct air at the calipers, and so far all is well. Even running at Monza I didn't pop any of my temperature strips, so the calipers never even hit 370 Fahrenheit.

https://f87.bimmerpost.com/forums/sh...ht=brake+ducts

How'd you attach the camera in there?? I'm interested in trying that out myself

[FlyingLow78]

Originally Posted by HA55L3R

How'd you attach the camera in there?? I'm interested in trying that out myself

Post #92: https://f80.bimmerpost.com/forums/sh...1422652&page=5

[behindthen0thing]

I really like the idea of the this brake duct idea. I just don't like the way the duct and hoses hang low a bit.
There must be a way to do something similar and moving the air inlet to the front of the car and if not, perhaps have the duct inlet flush with the bottom of the car similar to a hood vent.
On a side note I think the hoses would be better secured with adel clamps rather than zip ties.
I saw another setup which had a stiffer looking hose that did not require any clamps and seems to route well also.

[FlyingLow78]

Originally Posted by behindthen0thing

I really like the idea of the this brake duct idea. I just don't like the way the duct and hoses hang low a bit.
There must be a way to do something similar and moving the air inlet to the front of the car and if not, perhaps have the duct inlet flush with the bottom of the car similar to a hood vent.
On a side note I think the hoses would be better secured with adel clamps rather than zip ties.
I saw another setup which had a stiffer looking hose that did not require any clamps and seems to route well also.

The scoops are the best solution I've found so far. Hanging below the lower arms is not such a big deal, as long as you are aware of speed bumps and approach them correctly. Even then, going over some huge ones near Monza wasn't a problem, and I have actually gained a lot of confidence in the setup's ability to clear obstacles. The aluminum belly pan actually hangs lower due to suspension travel and the scoops are fairly static in height since they're close to the wheels.

It is possible to route the inlets to the kidney grills, but it's a compromise. A clear path exists from the wheel arch interior to the kidneys if you are willing to cut the fender liner a bit, but you would need to re-route the engine air intake or share the opening. I wasn't willing to do that since the performance is excellent already.

The hoses aren't secured with anything at the moment, other than a worm gear clamp at each end. The hose is slightly pinched in the middle where it passes between the knuckle and shock body. Zip ties hold the scoop to the lower arm and allow it to break off if it hits something. Adding adel clamps wouldn't make it perform any better or be more secure. The CEET hose I am using is fairly stiff, and I wouldn't recommend going for something less flexible because it will pull on the scoop and/or the rotor shield.

[behindthen0thing]

Originally Posted by FlyingLow78

The scoops are the best solution I've found so far. Hanging below the lower arms is not such a big deal, as long as you are aware of speed bumps and approach them correctly. Even then, going over some huge ones near Monza wasn't a problem, and I have actually gained a lot of confidence in the setup's ability to clear obstacles. The aluminum belly pan actually hangs lower due to suspension travel and the scoops are fairly static in height since they're close to the wheels.

It is possible to route the inlets to the kidney grills, but it's a compromise. A clear path exists from the wheel arch interior to the kidneys if you are willing to cut the fender liner a bit, but you would need to re-route the engine air intake or share the opening. I wasn't willing to do that since the performance is excellent already.

The hoses aren't secured with anything at the moment, other than a worm gear clamp at each end. The hose is slightly pinched in the middle where it passes between the knuckle and shock body. Zip ties hold the scoop to the lower arm and allow it to break off if it hits something. Adding adel clamps wouldn't make it perform any better or be more secure. The CEET hose I am using is fairly stiff, and I wouldn't recommend going for something less flexible because it will pull on the scoop and/or the rotor shield.

I've got an APR air dam on the front of my car.
It's my thought I could run the inlet to connect to that air dam and sit on the top side of it while sucking the air from right below the air dam.
I haven't had my car in 3 weeks now, so I don't have a chance to look at it more closely. Maybe this weekend I'll be able to.

[sna66]

this is awesome for those that track, seems like something that BMW should consider adding to M cars.

[drroc]

So I managed to print one scoop out of nylon. The nylon scoop is pretty flexy and should not crack if there is an impact. I am having a ton of trouble of printing out the mirror image for the other side. For whatever reason, the nozzle gets clogged. I might try a different slicer for that...

[CRRobert]

Thanks to all for the info, I am planning to utilize the 3D printed ducts in the front and the GT3 Ducts in the rear. All with stock brake discs, calipers, with Ferodo DS1.11 pads and titanium shims with max NT01/RE71 tires.

I printed one set with PLA+ to get sense for the printing and fitment. For final use, what would be the recommended filament, Nylon, ABS, other? Not so much worried about replacing if break, but would be more concerned about debris that could be left on the track if is did and the best to prevent if that makes sense.

Also any tips on printing specs, material, etc? Using Lulzbot Taz6.

What are people using to bond the two pieces, and would it be better to print one piece at a time vs 2?

Thanks in advance!

[FlyingLow78]

Originally Posted by CRRobert

Thanks to all for the info, I am planning to utilize the 3D printed ducts in the front and the GT3 Ducts in the rear. All with stock brake discs, calipers, with Ferodo DS1.11 pads and titanium shims with max NT01/RE71 tires.

I printed one set with PLA+ to get sense for the printing and fitment. For final use, what would be the recommended filament, Nylon, ABS, other? Not so much worried about replacing if break, but would be more concerned about debris that could be left on the track if is did and the best to prevent if that makes sense.

Also any tips on printing specs, material, etc? Using Lulzbot Taz6.

What are people using to bond the two pieces, and would it be better to print one piece at a time vs 2?

Thanks in advance!

I’ve had good luck with ABS so far. I haven’t tried anything else because I leave it to the experts at work to do the printing. Debris is just plastic, and the one scoop I accidentally broke sheared off cleanly.

The two pieces need not be bonded together. In a brilliant bit of design engineering, the small circular piece is inserted inside the scoop and fits through the hole. Once you install the hose and clamp it to the smaller piece, the scoops can rotate independently of the hose and the clamp holds the whole thing together.

If your printer is small you may have to do one side at a time. Ours was big enough to handle both.

[drroc]

Originally Posted by CRRobert

Thanks to all for the info, I am planning to utilize the 3D printed ducts in the front and the GT3 Ducts in the rear. All with stock brake discs, calipers, with Ferodo DS1.11 pads and titanium shims with max NT01/RE71 tires.

I printed one set with PLA+ to get sense for the printing and fitment. For final use, what would be the recommended filament, Nylon, ABS, other? Not so much worried about replacing if break, but would be more concerned about debris that could be left on the track if is did and the best to prevent if that makes sense.

Also any tips on printing specs, material, etc? Using Lulzbot Taz6.

What are people using to bond the two pieces, and would it be better to print one piece at a time vs 2?

Thanks in advance!

I would say that nylon is the best as it can flex quite a bit and go back into the original shape. ABS or PETG would just crack. I ended up using epoxy glue to join the two pieces together. https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1 This worked pretty well. The main hassle is to figure out if your extruder will support support flexible filaments without clogging up. I had to print some extruder replacement parts for my FlashForge Creator Pro to solve the clogging issue. Temperature control is a bit tricky and it helps a lot to have en enclosure.

You can also try to use PETG filament as it is supposed to be similar to the strength of ABS, but it is far easier to print in my experience as it is not as temperamental.

[drroc]

So I was curious about the performance of the 3D printed duct vs the previous setup that I used. I bought a Pyle anemometer to measure the airflow in mph inside the duct. I was curious to see how the airspeed in the duct corresponded to the vehicle speed.

With the 3D printed duct, the airspeed inside the duct is roughly 1/2 of travel speed. It gets somewhat faster as the vehicle travels faster as well. The max speed I hit was 48.6 mph (this was around 83mph or so). It was also interesting to see the impact of SUVs/trucks ahead of me. They caused a drop in the airspeed inside the duct.

I have also tried out my previous design. I thought that it would do better because it did better in my static leaf blower test as the wind meter read higher speeds. To my surprise, the wind speed didn't really exceed 25mph even at freeway speeds. I suppose, this has to do with the shape of the front bumper.

This was all in the name of science of course

[FlyingLow78]

drroc Thanks for bringing actual data to this discussion! I briefly looked into using a pitot tube arrangement to measure airflow at various parts of the car with the Porsche scoops installed, but decided to just go old school and just used tufts of yarn to see what direction the airflow was going.

https://f87.bimmerpost.com/forums/sh...php?p=25290576

[drroc]

Originally Posted by FlyingLow78

drroc Thanks for bringing actual data to this discussion! I briefly looked into using a pitot tube arrangement to measure airflow at various parts of the car with the Porsche scoops installed, but decided to just go old school and just used tufts of yarn to see what direction the airflow was going.

https://f87.bimmerpost.com/forums/sh...php?p=25290576

That was a cool experiment of trying to measure laminar flow.

I am right now printing another set of scoops as I want to try them on the rear wheels as well. I'll report back with the findings in two weeks or so.

[FlyingLow78]

The rears don’t do a lot compared to the fronts, and I’ve found that the Porsche front scoops fit beautifully on the rear and direct air straight at the caliper. Mine survived Monza with no issues. More power to ya if you want to add them, though.

[drroc]

Originally Posted by FlyingLow78

The rears don’t do a lot compared to the fronts, and I’ve found that the Porsche front scoops fit beautifully on the rear and direct air straight at the caliper. Mine survived Monza with no issues. More power to ya if you want to add them, though.

The rears do still get hot enough to make pinging noises after 20mins session at Laguna Seca. I am bit scared to disable DSC completely at Laguna since it has so many walls. I am pretty sure the DSC system keeps the rears hot as I see the MDM flashing light quite often. Since I already have the 2.5inch flanges on rear dust shields, it should be straight forward to install the ducts for the rear. I just need to find the time to do it.