locating/planning a defroster vent without the body

[toadster]

I'm on the fence about putting in a defroster vent, I have heat & A/C and there's room on the driver side for a vent, but probably not the passenger side without creating a whole new vent and space is at a super premium...
is there a guideline on how much 'hose' should be used to locate the vent? I know in general you want the hose as taught as possible to reduce airflow disturbances

has anyone done just a driver side defroster? I know it's a roadster, but my buddy the other night used his defroster because the dewpoint got low enough to fog up his inner windshield and it helped tremendously

also, if a soft (or hard) top goes on in the future, it would probably be beneficial as well

[Jeff Kleiner]

Almost every one I've done has a functional defrost vent on the driver's side only and a non-functional grill on the passenger side. The heater box &/or glove box usually makes it virtually impossible to get a hose on a boot on the passenger side.

Jeff

[BUDFIVE]

Jeff, is the heater box in the way for a functional passenger side defrost vent with the FFR heater installed per the instructions? If so, what do you do with the top passenger side box output? I’m about to pull the trigger on the FFR heater/defrost kit this week as other kits don’t have the box outputs on the side which is all we have room for, right?

Toadster, glad you started the thread.

[Norm B]

North Racecars sells a plenum to solve this issue https://northracecars.com/heat_ac.html. Scroll down the page on the link.
I made my own adapter to allow defrost on the passenger side.

HTH
Norm

[FLPBFoot]

Jeff, is the heater box in the way for a functional passenger side defrost vent with the FFR heater installed per the instructions? If so, what do you do with the top passenger side box output? I’m about to pull the trigger on the FFR heater/defrost kit this week as other kits don’t have the box outputs on the side which is all we have room for, right?

I installed the heater but did not put in the defrost vents. I cut off two outputs and then formed a block off plate out of AL and riveted into place with sealer to the openings.

[OSU Cowboy]

I've got the North Racecars plenum ... works well and makes the defrost vent openings much less mentally contentious.

[toadster]

will check with the painter/body guy (KenP) about the North Racecars plenum - looks like that may work!!!

Thanks guys!!

[egchewy79]

Jeff, is the heater box in the way for a functional passenger side defrost vent with the FFR heater installed per the instructions? If so, what do you do with the top passenger side box output? I’m about to pull the trigger on the FFR heater/defrost kit this week as other kits don’t have the box outputs on the side which is all we have room for, right?

Toadster, glad you started the thread.

I capped off my unused port with a large rubber end cap.
can't remember the exact OD of the port but something similar to this.
https://www.amazon.com/Prescott-Plastics-Round-Flexible-Rubber/dp/B07RDMNGP4/ref=sr_1_3?keywords=2%2Binch%2Brubber%2Bcaps&qid=1704376989&sr=8-3&th=1

[Jeff Kleiner]

I think a lot depends on exactly how and where the heater box is mounted as well as what defroster boot you're using. The ones that point straight down are generally a no-go. I had a North Racecars plenum supplied by one owner and due to conflict I had to cut it up, reshape it and and then 'glass it all back together before fiberglassing it to the underside of the cowl. I use rubber Fernco test plugs to cap the unused heater box ports. You'll find them in the plumbing section of your local hardware store, Lowes, etc.

https://images.thdstatic.com/productImages/5a597403-ac72-43ec-b42b-8bcef4170e42/svn/black-the-plumber-s-choice-pvc-fittings-e21171112n-64_145.jpg

Jeff

[Jrmotorsports55]

I was able to install both on both sides as functional, but I have a custom heater box setup. Videos in my build thread below if interested.

[toadster]

I was able to install both on both sides as functional, but I have a custom heater box setup. Videos in my build thread below if interested.

wow love the innovation in your setup, I'm subscribed to your youtube as well ;)

[Jrmotorsports55]

Much appreciated! Thanks!