Heater tube

[Robert Abbott]

Is there any reason not to remove the flex heater tubes in the summer. Even with the heater flapper open and the vents closed I still get heat into the passenger cabin.

[Tom Tate]

Robert,
No reason to not to take off the heater tubes, except:
1. Porsche didn't do it that way
2. When adjusted correctly the flaps will keep heat (and noise) out
3. If not adjusted correctly and the tubes gone, the heat will be blown onto the
gearbox, not good
4. Fix it right once vs fix it twice a year every year

KTF

[Guest]

Tom may be right. There may be an affect (or maybe not) on the tranny. I removed my flexible heater tubes 20 years ago and never replaced them. I live in California where I don't use the heat, so I may be a special case. I just got tired of the metal slide opening every once in a while in the driving compartment, and having my left foot cooked. No ill effects to date on my foot or my gearbox.

[Brian R Adams]

I've removed my flapper boxes entirely and replaced them with 2-inch ID pre-formed foam pipe insulation. Cut them to ~14-inches (start a little longer and trim!) and then wiggle it onto the end of the heater box where the flapper box clamps on, then scrunch it shorter and slide it onto the tube where the heater hose normally goes. On the passenger side
you will have to bend it to get around the axle and you may have to move the parking brake cable aside, it's kind of snaky. I had to cut a shallow notch (not all the way through the foam wall) to make a slight elbow in one spot. The thinner the foam tube, the easier it is to bend. (I think I found 3/8" wall, and it is rather stiff.) If you cut the tubes long enough that you need to scrunch them to get them installed, they will spring back to static length and hold themselves in place, and you won't need any clamps.

In summer I simply pull off the forward end and tuck it aside, which creates instant fresh air circulation on your feet. When I need to hook it back up again, it takes ten seconds reaching under the car. And you can stow your old rusty/broken flapper boxes and associated linkage parts. Now when I actuate the heater control, all the cables have to move are the main heater box flaps, so there is less drag on the cables and fewer adjustments required.

PS In winter with the tubes installed, I can't tell a difference in noise (the flappers are ostensibly sound mufflers as well as valves) but when the main heater flaps are closed, a bit of heated air does get through, since there is no longer a flapper valve in the tube.

This setup is not concours, but it is not visible except by crawling under the car, so it doesn't spoil the curb appeal.

[Robert Abbott]

Thanks for the input, I like the idea of wrapping the tube around to get air flow during the summer months. I live in Maryland, Its hot gets very hot here. I have a lift, so its very simple for me to get underneath and switch.

[Brian R Adams]

Actually, rather than bother with turning the flexible OEM style tubes around (pointing them into the air flow) just remove them entirely, or remove the *front* ends and push them to the side to open the tunnel holes. I've found you get just as much flow into the cab with nothing at all attached to the tunnel entrances as when you have a U-shaped tubes attached. Something about the way air flows under the car and creates pressure zones, you don't really need an "air scoop."

As an experiment, I went to Home Despot and bought some plastic 90-degree plumbing elbows, chained them together to form 180-degree elbows, and made wide-mouth, forward-facing air scoops, using hose clamps to attach them. I honestly couldn't feel much difference in air volume at the floor vents compared to just the open rear-facing tunnel holes, maybe 5%.