petawawarace Posted June 11, 2021 Report Share Posted June 11, 2021 I’m building a fresh air system for our helmets and was looking for a bit of advice. - It’s a DIY system, I’ve got a small fan, tubing and the helmets pieces. - Where is the best location for the inlet? I could use a side window Naca duct, but I’m worried about rain getting in. Just build a drip point in at the bottom? Would this be too much flow at higher speeds? - what should I use for a filter? Is a filter even necessary? Thanks. Quote Link to comment Share on other sites More sharing options...
Originalsterm Posted June 11, 2021 Report Share Posted June 11, 2021 We have a side window NACA duct on the rear side window of an E30. There is probably 5' of flexible tubing that basically just points towards the driver for some fresh air inside the car. Never had any water blast through it and we've been in some pretty hard rain. 1 Quote Link to comment Share on other sites More sharing options...
petawawarace Posted June 11, 2021 Author Report Share Posted June 11, 2021 I should clarify, this will be a fresh air system that connects to the helmet. We've tried the ducting just pointing at the driver, but my father finds the fumes too bad still. I will be making a coil for use with our coolsuit system and ice box to try to cool the air as well. 1 Quote Link to comment Share on other sites More sharing options...
Originalsterm Posted June 11, 2021 Report Share Posted June 11, 2021 Still, I wouldn't expect there to be any rain getting in or a need for a filter in a setup similar to ours. It could be different if you used a smaller duct on the front window and had a shorter run of tubing. In that case, it may not be comparable to our setup so I'd defer to someone who is setup this way. 1 Quote Link to comment Share on other sites More sharing options...
BollingerChump Posted June 11, 2021 Report Share Posted June 11, 2021 The OE HVAC inlet is at the cowl below the windshield because there's a high pressure zone there..if you haven't cut out the whole hvac intake it probably has a drip pan already, just will need to adapt to the outlet. We did so with a large diameter PVC fitting, blow torch, and pop rivets..might even have room to put a carbon cabin filter to draw through. 4 Quote Link to comment Share on other sites More sharing options...
TiredBirds Posted June 11, 2021 Report Share Posted June 11, 2021 2 hours ago, petawawarace said: I should clarify, this will be a fresh air system that connects to the helmet. We've tried the ducting just pointing at the driver, but my father finds the fumes too bad still. I will be making a coil for use with our coolsuit system and ice box to try to cool the air as well. you should work on re-routing the exhaust. Even with the vent, CO2 is still getting in the car. 2 Quote Link to comment Share on other sites More sharing options...
petawawarace Posted June 11, 2021 Author Report Share Posted June 11, 2021 14 minutes ago, TiredBirds said: you should work on re-routing the exhaust. Even with the vent, CO2 is still getting in the car. It’s not exhaust fumes. His biggest complaint was the brake fumes. We did have a small opening in the door panel that we’ve sealed up, but I’m going to use this as a cooling device on hot days too. 33 minutes ago, BollingerChump said: The OE HVAC inlet is at the cowl below the windshield because there's a high pressure zone there..if you haven't cut out the whole hvac intake it probably has a drip pan already, just will need to adapt to the outlet. We did so with a large diameter PVC fitting, blow torch, and pop rivets..might even have room to put a carbon cabin filter to draw through. Great idea. I should be able to tap into that easily. Quote Link to comment Share on other sites More sharing options...
ross2004 Posted June 11, 2021 Report Share Posted June 11, 2021 (edited) 3 hours ago, petawawarace said: I will be making a coil for use with our coolsuit system and ice box to try to cool the air as well. Run the air through a water-to-air intercooler plumbed with the cool shirt water. I have the fan for my helmet air mounted on the roll cage main hoop at the passenger side window. Edited June 11, 2021 by ross2004 1 Quote Link to comment Share on other sites More sharing options...
Ian Posted June 12, 2021 Report Share Posted June 12, 2021 18 hours ago, petawawarace said: It’s not exhaust fumes. His biggest complaint was the brake fumes. We did have a small opening in the door panel that we’ve sealed up, but I’m going to use this as a cooling device on hot days too. Great idea. I should be able to tap into that easily. What brake pads are you using? We've found that the wrong pad choices are extremely smelly and distracting, while pads that working well and at proper temp have no smell at all. Quote Link to comment Share on other sites More sharing options...
petawawarace Posted June 12, 2021 Author Report Share Posted June 12, 2021 2 hours ago, Ian said: What brake pads are you using? We've found that the wrong pad choices are extremely smelly and distracting, while pads that working well and at proper temp have no smell at all. DTC 60. Brakes are working very well. In his old age, my dad has become more sensitive to these things. I don’t notice the fumes at all. Regardless, I’m trying to fix it for him. 2 Quote Link to comment Share on other sites More sharing options...
mender Posted June 12, 2021 Report Share Posted June 12, 2021 22 hours ago, TiredBirds said: you should work on re-routing the exhaust. Even with the vent, CO2 is still getting in the car. I added a 45 degree turndown to my exhaust outlet and that helped my situation. 4 Quote Link to comment Share on other sites More sharing options...
MMiskoe Posted June 13, 2021 Report Share Posted June 13, 2021 I would spend some time looking at NASCAR cars. I don’t know where they pick up the air, but I do know they run helmet ducts. I am also pretty sure that they bring more to bear than most Champ teams when it comes to R&D so they probably have tried a few things and come up with a good solution. Quote Link to comment Share on other sites More sharing options...
Rodger Coan-Burningham Posted June 13, 2021 Report Share Posted June 13, 2021 We have used a naca duct for this for several years, never had an issue with water getting to the helmet. I actually quit using it last year and just use that air to the back of the drivers neck. I have another naca duct with hose routed along the top roll cage bar bringing air to the face of the driver. Works good. Quote Link to comment Share on other sites More sharing options...
Clifford Beisler Posted June 13, 2021 Report Share Posted June 13, 2021 We use a naca duct in the side window. It work great. We also used some of these vents in the roof just above the drivers visor. They can pop them open very easily. https://www.aircraftspruce.com/catalog/appages/snapvents3.php 1 Quote Link to comment Share on other sites More sharing options...
Gkuhn41 Posted June 14, 2021 Report Share Posted June 14, 2021 On 6/11/2021 at 8:42 AM, petawawarace said: I should clarify, this will be a fresh air system that connects to the helmet. We've tried the ducting just pointing at the driver, but my father finds the fumes too bad still. I will be making a coil for use with our coolsuit system and ice box to try to cool the air as well. We did this already, it blew through ice in like 30 minutes running 50% but man that helmet blower was COLD! Quote Link to comment Share on other sites More sharing options...
Rodger Coan-Burningham Posted June 14, 2021 Report Share Posted June 14, 2021 51 minutes ago, Gkuhn41 said: We did this already, it blew through ice in like 30 minutes running 50% but man that helmet blower was COLD! I forgot to mention we did this as well, as Greg says the ice is gone quickly, but nice while it lasts. Quote Link to comment Share on other sites More sharing options...
petawawarace Posted June 14, 2021 Author Report Share Posted June 14, 2021 (edited) Oh yeah? Were you guys using ice cubes or bigger blocks? And how many loops did you have through the cooler? I was thinking some 1” copper tubing. Edited June 14, 2021 by petawawarace Quote Link to comment Share on other sites More sharing options...
Rodger Coan-Burningham Posted June 14, 2021 Report Share Posted June 14, 2021 16 minutes ago, petawawarace said: Oh yeah? Were you guys using ice cubes or bigger blocks? And how many loops did you have through the cooler? I was thinking some 1” copper tubing. I just bought the cooler that Cool Shirt sells that has one single loop passing through the cooler that the helmet air blows through. Because of it taking up space we had to use bags of ice. I’m not really sure how much difference that really makes it’s all about transfer of BTUs. Quote Link to comment Share on other sites More sharing options...
petawawarace Posted June 14, 2021 Author Report Share Posted June 14, 2021 32 minutes ago, Rodger Coan-Burningham said: I just bought the cooler that Cool Shirt sells that has one single loop passing through the cooler that the helmet air blows through. Because of it taking up space we had to use bags of ice. I’m not really sure how much difference that really makes it’s all about transfer of BTUs. It makes a huge difference in slowing that transfer down. Way less surface area to contact the warm water. You can 3D print molds for the blocks too. Make them any size/shape you want. 2 Quote Link to comment Share on other sites More sharing options...
Rodger Coan-Burningham Posted June 15, 2021 Report Share Posted June 15, 2021 3 hours ago, petawawarace said: It makes a huge difference in slowing that transfer down. Way less surface area to contact the warm water. You can 3D print molds for the blocks too. Make them any size/shape you want. Good point, but me 3D printing anything probably ain’t happening. I would like to see what you end up doing there however. I am thinking regardless of how fast or slow the heat transfer is, it’s still a matter of there only being so much energy available in a cooler full of ice. Either the coolshirt doesn’t cool as much, or the helmet , or both run out and you are just hot. But I guess the way you are going about it you will find that balance. 2 Quote Link to comment Share on other sites More sharing options...
TimS Posted June 15, 2021 Report Share Posted June 15, 2021 (edited) 14 hours ago, Rodger Coan-Burningham said: me 3D printing anything probably ain’t happening I’m with you. I’m going to try aluminum loaf pans to make my own ice blocks/bricks. I’m looking at a 12v freezer to keep them frozen too. All low budget as possible too. Edited June 15, 2021 by TimS Quote Link to comment Share on other sites More sharing options...
Gkuhn41 Posted June 16, 2021 Report Share Posted June 16, 2021 (edited) we took 1/4" copper tubing wrapped it around 1.5" pvc to make a coil, then put that inside some 3" PVC with each end of the coper sticking out of the 3" elbows then blew air through that. to the helmet. We mounted it all to the bottom side of cooler lid, put a bilge pump in it and T'd the line so one went to the coolshirt and one to the helmet coil. If you want pictures PM me your email and ill ship some over. Hell if you want the cooler let me know i still have it you can give it a whirl. Edit: We were able to obtain up to a 20* drop in air temp from enter to exit of the cooler. We could do more if we slowed the air down or added a divider to lengthen the contact time i am sure. We used bags of ice, blocks would be better 100% I thought about a Air transfer system using dry ice nasty cold. But gasses off and you need to deal with that.. Smoke and racecars are not a good combo. Edited June 16, 2021 by Gkuhn41 Quote Link to comment Share on other sites More sharing options...
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