Fresh air kit

[first time builder]

Is anybody still making a fresh air kit >?

[toadster]

I think to build your own is pretty straightforward... I haven't set mine up yet, but here are the parts

Components (modified from Fman's build (https://thefactoryfiveforum.com/showthread.php?35778-Fmans-Dart-427-build-9818-Nor-Cal-1k-mile-build-review&p=425546&viewfull=1#post425546))
$26 (2) Woodstock W1141 3-Inch Aluminum Blastgate (https://amzn.to/37MUTMO)
$50 (2) SEAFLO 3" In-Line Marine Bilge Air Blower 12V (https://amzn.to/3xV4yf3)
$15 (1) 3 Inch 16 Feet Air Duct Flex Air Aluminum Foil Ducting Dryer Vent Hose HVAC Ventilation for Grow Tents, Dryer Rooms, Kitchen, 2 Clamps Included (https://amzn.to/3gawjKt)
$16 (2) JEGS Hand Choke Cable | Fits Most Carburetor Applications | 6 Foot Length | 1” OD Knob Requires 1/2 “ Mounting Hole (https://amzn.to/3yVPi2N)

$107 for the main parts above

if you're doing the electric blower motors you'll have to think of switches as well... pick a switch - cost varies

[PaulProe]

As many or as few of components as you need:

https://prdcrrct.com/product-category/air-vents/

[first time builder]

Thanks for the responses.

[juddster]

I am right in the middle of my fresh air build for my MK4. I have built upon a lot of what has been shared (shout out to GTBradley), but didn't want to use a manual cable pull to open and close the vent system. I found an electric damper/valve on my own and this has also shown up in a post on the forum. I haven't seen this electric valve used yet, so it is an experiment.

Here is my list of components:
1. Tubing: https://www.amazon.com/gp/product/B06XKQML35/ref=ppx_yo_dt_b_asin_title_o03_s02?ie=UTF8&psc=1
This tubing is more rigid than some others that have been posted, but they also need to be insulated. GTBradley found that the headers may heat up the tubing, which heats up the incoming air and so he insulated his tubing. I will do the same. I think there could be some better options out there for tubing. The dryer vent tubing may reflect the heat better, but they are not as rigid.
2. Blowers: Same link as toadster above
3. SS Elbows: https://www.amazon.com/gp/product/B088BH7X37/ref=ppx_yo_dt_b_asin_title_o03_s01?ie=UTF8&psc=1
I like these to transition into the footbox. The link shows unavailable, but other options show up that you can click on.
4. Footbox vents: https://www.amazon.com/gp/product/B01DXASSZW/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1
I didn't just want a hole in the footbox and it provides a more secure attachment to the footbox. Not needed if you don't want them.
5. Vent boots: https://www.amazon.com/gp/product/B006K8K8HG/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

Here is what I am going to use to move from cable operation to electric switch operation:
6. Electric valve/damper: https://www.aliexpress.com/item/33012618807.html?spm=a2g0s.9042311.0.0.1cf94c4d7kt wAg
These will be delivered any day and I will test to see if this works.
7. 3-way switch: https://www.ebay.com/itm/333591672368?var=542692533999
Using the switch is new. Here is my plan. The switch has 3 positions. The center switch position will have the fan off and have the electric vent closed. The right switch position will have the fan off but the vent open, which will be nice while driving. The left switch position will have the fan on and have the vent open, which will be good for either driving or when stopped. I have heard that others have enjoyed the fan on while sitting at stop lights. For now I plan on having the switches mounted on the trans tunnel within easy reach of driver and passenger for quick control.

I will post the build when I get it done and working.

Hope this helps!!

[first time builder]

Thank you juddster ! Looking forward to your install !

[juddster]

All right. Finally got all the components. The first valves that I got were the wrong voltage and I had to get new ones. They take about 2 weeks to arrive.

Here is the overall set up:
153730

Up close pics:
153718
153719
The valve is barely audible and fans were quieter than expected. The valve is from China so I hope it holds up, which it should since it won't be cycled much.
153720
The blue is lay flat rubber hose. Very cheap ~$2/foot. They just gave me about 18" worth. Thanks EVCO!

Here is how the switch works:
153717

I have tested this and it works great! My thinking is to have the switch natural position (middle) keep the valve open. Switch to the left and the fan turns on and then switch to the right and the fan turns off and valve closes. The valve uses a motor to move the butterfly valve and then when it is fully closed or fully open it stops and does not consume power. So this can be left in the open or closed position no problem.

More pics of the switch. Comes with a great pigtail.
153728
153729

The only things left are to get the wiring laid out and fused, then find a bezel to label FAN - VENT - OFF

And to fasten the hosing. Either hose clamps or rivets. The rivets may not be a long term solution.

And install!

[first time builder]

That looks like its fantastic can you let us know the approx cost ?

[Avalanche325]

My suggestions.

If this is going in the standard, through the wheel wells location, use high temp hose. The heat from the headers will slowly melt hose that can't handle the heat.

I replaced my blast gates, that started to stick and always felt cheap, with modified exhaust cutouts. Much happier with them.

[Fman]

Not to hijack but are you guys getting good results with your fresh air system? Mine is terrible, I get hot air blowing out of them. I ran my house directly from front air ducts (even bought moulded plastic piece to create a good seal) into 3" bilge blower, tucked up high under fender then into the footbox. Does no good at this point on an 85 degree day to have hot air blowing on me. I have replaced my hoses with insulated hose and it got a little better but not worth turning on. I think they might actually be used as heaters this winter.

Any suggestions would be great....thanks

[toadster]

Not to hijack but are you guys getting good results with your fresh air system? Mine is terrible, I get hot air blowing out of them. I ran my house directly from front air ducts (even bought moulded plastic piece to create a good seal) into 3" bilge blower, tucked up high under fender then into the footbox. Does no good at this point on an 85 degree day to have hot air blowing on me. I have replaced my hoses with insulated hose and it got a little better but not worth turning on. I think they might actually be used as heaters this winter.

Any suggestions would be great....thanks

I think your exhaust fans blowing hot air from the engine bay out your side vents will keep things cooler... those are 4" right?
I'll be excited to try my footbox vents out since my headers are JetHot coated, may reduce the thermal leak - pretty much used your setup and went with some thermal'ish tubes :)

[OSU Cowboy]

I got a fresh air kit from Cobra Earl - years back of course. For the hose from the fan to the footbox, I used 3" aluminum dryer hose. On the driver side, that hose routes from above the wheel well under the header into the lower area of the footbox. I wrapped that section with header wrap knowing without doing that I'd get some unwanted effects from the header heat. Passenger side is routed well above the headers into the top of the footbox - so no header wrap there. The gates are manually operated with cable. I can't say I regret doing this, but I also can't say that I use it much at all with 13000 miles experience. On hot days - you get hot air. On cool days - it's not really needed. I do have the footboxes insulated within an inch of their lives.

[Dieter123]

I used all the parts from GTBradley's concept but instead of a switch,,,,I used these fan speed controllers>>>DC 12V 24V Motor Speed Controller Switch Car Truck Fan Heater Control Defroster>>>https://www.ebay.com/itm/114355723500.

[GTBradley]

Not to hijack but are you guys getting good results with your fresh air system? Mine is terrible, I get hot air blowing out of them. I ran my house directly from front air ducts (even bought moulded plastic piece to create a good seal) into 3" bilge blower, tucked up high under fender then into the footbox. Does no good at this point on an 85 degree day to have hot air blowing on me. I have replaced my hoses with insulated hose and it got a little better but not worth turning on. I think they might actually be used as heaters this winter.

Any suggestions would be great....thanks
I did get positive results from adding the foam wrap and reflective HVAC tape, though it looks a little like Mars rover part, but it still is not ambient air. The major problem I believe is radiant heat from the headers and whatever you can do to reflect that does help. I use mine frequently and it's nice to have air moving. However, the major advantage of my system is defogging the cabin when the top is on in rain. It works exceedingly well for that.

[juddster]

Not to hijack but are you guys getting good results with your fresh air system? Mine is terrible, I get hot air blowing out of them. I ran my house directly from front air ducts (even bought moulded plastic piece to create a good seal) into 3" bilge blower, tucked up high under fender then into the footbox. Does no good at this point on an 85 degree day to have hot air blowing on me. I have replaced my hoses with insulated hose and it got a little better but not worth turning on. I think they might actually be used as heaters this winter.

Any suggestions would be great....thanks


Hijack away! This has created some great content and good details.

Looks like I need to reconsider what I use for the hose and consider shielding of some sort. I had already planned to have some polished stainless steel sheets attached with stand offs to the footbox areas to shield against header heat. I may add this shielding to above the headers as well. Still thinking this through.

[juddster]

That looks like its fantastic can you let us know the approx cost ?


Hose: $28
Blowers: $50
SS Elbows: $16
Vents: $18
Front Ducts: $40
Valve: $50
Switches: $34
Total:$236

That adds up pretty quick. Hope it works!

[Hoooper]

Looks like I need to reconsider what I use for the hose and consider shielding of some sort. I had already planned to have some polished stainless steel sheets attached with stand offs to the footbox areas to shield against header heat. I may add this shielding to above the headers as well. Still thinking this through.

Using good double layer hose seems to help. I used the expensive double layer orange silicon hose and the air I get feel pretty close to ambient.

[BrewCityCobra]

All right. Finally got all the components. The first valves that I got were the wrong voltage and I had to get new ones. They take about 2 weeks to arrive.

Here is the overall set up:
153730

Up close pics:
153718
153719
The valve is barely audible and fans were quieter than expected. The valve is from China so I hope it holds up, which it should since it won't be cycled much.
153720
The blue is lay flat rubber hose. Very cheap ~$2/foot. They just gave me about 18" worth. Thanks EVCO!

Here is how the switch works:
153717

I have tested this and it works great! My thinking is to have the switch natural position (middle) keep the valve open. Switch to the left and the fan turns on and then switch to the right and the fan turns off and valve closes. The valve uses a motor to move the butterfly valve and then when it is fully closed or fully open it stops and does not consume power. So this can be left in the open or closed position no problem.

More pics of the switch. Comes with a great pigtail.
153728
153729

The only things left are to get the wiring laid out and fused, then find a bezel to label FAN - VENT - OFF

And to fasten the hosing. Either hose clamps or rivets. The rivets may not be a long term solution.

And install!

I really like the electric valves you used. Quick question - I went on the website you linked to and there was some refernce to a controller. Is that something you needed to purchase as well or was the valve and switch you have depicted sufficient to operate the system?

[juddster]

The switch and valve are all you need. Just make sure you get a 12V valve.

[juddster]

Update to the fresh air kit.

Ended up adding some silicon/fiberglass hose to the middle part for more stiffness and more heat protection from the exhaust. It was more expensive than I had planned ($80 each side), but I am happy with the end result.

https://thefactoryfiveforum.com/attachment.php?attachmentid=168891&d=1656861183

https://thefactoryfiveforum.com/attachment.php?attachmentid=168895&d=1656861183

https://thefactoryfiveforum.com/attachment.php?attachmentid=168894&d=1656861183

https://thefactoryfiveforum.com/attachment.php?attachmentid=168893&d=1656861183

Also made a bracket to hold the valve/blower switch and the seat heater switch. The bracket with switches will be mounted on top of the transmission tunnel, forward toward the dash. I'll post pictures of that later.

https://thefactoryfiveforum.com/attachment.php?attachmentid=168892&d=1656861183

[john42]

Over the last couple of hot days, I've been chasing down every hole, crack and and space that hot air is(was) coming through. After 4 rounds of insulation, heat wrapping, aluminum taping my foot box now stays the same temp as ambient air. Was out driving a few hours in 95F in stop in go traffic this past Friday and was finally not feeling my feet being roasted in an oven. The air down in the foot box felt the same as the wind in my face. Mission success! Air vents were going to be my next mission but, as of Friday I don't feel that they are needed. If I were building the car today however, I'd 100% do them.

[AC Bill]

Were some builders using brake cooling duct hose to avoid the heat related issues from the header on the hose? I seem to recall some sort of fire/heat proof duct hoses being used.

When I built my car, I initially looked at bilge blowers, but they didn't seem to move as much air as I was hoping for. Perhaps there is better blowers that have a higher volume, but the ones I bought were very poor. Noisy too,.
Daring to be different, I ended up using a single 4 speed, squirrel cage fan, that feeds fresh air to both footboxes. Mounted in the trunk, using a blast gate, and a fresh air scoop, a 2-1/2" hose was run forward via the tranny tunnel to a T connection. Hoses from the T were a short run to outlets on the side of the footbox's. I insulated the hose, to negate heat, but it is never really subjected to engine/header heat, other than some from the tranny. The blast gate, fan speed and on/off are controlled from the cockpit.

The fan assy, with the custom plenum box I made, does take up a lot of room on the upper trunk shelf. This could be a set back for some if your planning a trip and carry a lot of luggage. Otherwise I have been very pleased with it.

[Rook]

Hey juddster, that silicone/fiberglass hose looks perfect! Where did you find it, if you don’t mind me asking?

[nucjd19]

I always love reading these threads. I often wondered should have I done this modification living in Alabama but after reading Fman and other posts it gave me pause. As an aside I used the Breeze koolmat and I have yet to feel ANY heat from the engine bay. This is coming from someone who lives in Alabama where I am driving in 100º F heat with high humidity. Really glad I pulled the trigger on that insulation. I do like the idea of using them for heaters in the winter though!!!!! Good Thought Fman !

[juddster]

Hey juddster, that silicone/fiberglass hose looks perfect! Where did you find it, if you don’t mind me asking?

I got it from abthermal.com. It's commonly referred to has firesleeve if you want to do a search.

The part number is AS1072-52 SIL-FG. Here is the catalog page: https://www.abthermal.com/pdffiles/S/SAE-AS1072-Aviation-Aerospace-Firesleeve.pdf. I used 2ft on each side. I just slid it over the hosing I already had.

It's about $37/ft, kinda pricey, but with the hose so close to the headers and the added stiffness it was worth it.

[Rook]

Great, thanks very much, juddster!

nucjd19: I've got thermal insulation too, just looking to make things as comfortable as possible within reason. I decided to go for the fresh air blowers because I just can't stand stagnant air. :) A little air flow and I'm all good! I had cowl vents in my 66 Mustang (no A/C) and they really did a nice job of making me comfortable even during the hot NC summers.

[nucjd19]

Great, thanks very much, juddster!

nucjd19: I've got thermal insulation too, just looking to make things as comfortable as possible within reason. I decided to go for the fresh air blowers because I just can't stand stagnant air. :) A little air flow and I'm all good! I had cowl vents in my 66 Mustang (no A/C) and they really did a nice job of making me comfortable even during the hot NC summers.

I hear ya! Makes total sense!

[maclonchas]

ACBill

I would be interested to learn a little more about your setup. Can you provide part numbers and a few more pictures?

Thanks

Bill

[Peeker]

IMO this was the biggest waste of time/money on my build. It’s not like the air is hotter than ambient, but it’s just that, ambient! Very little flow. Maybe if you run with a roof, which I do not, it may help some, but with no roof, it’s not gonna make a difference.

[john42]

IMO this was the biggest waste of time/money on my build. It’s not like the air is hotter than ambient, but it’s just that, ambient! Very little flow. Maybe if you run with a roof, which I do not, it may help some, but with no roof, it’s not gonna make a difference.

I'm doing this on my finished Cobra. I'm hoping to just get some airflow around my feet. At present it's just a non-moving pocket of heat. Even a slight breeze would be a welcome improvement.