Auxiliary 911 heating

[hilandscott]

Who else out there has wanted the torque that comes with using headers, while still having heat up front to keep the windshield clear of fog and frost? I'm hoping I'm not alone and that a few others have opened up, for example, the JC Whitney catalog and purchased an electric heater/blower that could be installed under the dash or in the front hood area.

As my engine does not have a heater blower, nor were the heat exchangers attached by the flexible lines to the body panels, I got in a few miles with no heat at all. Of course, rain is more likely than anything else, so keeping the haze off of the front glass is a must. I am thinking I will be fine in Georgia not reinstalling the factory system (how well does it work to keep the front glass clean anyway??)

Safety is the issue-- and I am hoping there is a way to put a switched system up front and power it off of the battery.

By the way -- really enjoy the new site... John

[wckrause]

How many watts does this electric heater/blower use?

You can still connect the heat exchangers to the flapper boxes without removing anything. It's difficult, but not impossible. Get some flexible metalic hosing. The engine fan provides most of the air movement except at idle, so the blower motor is not required. I've run for 10 years , in cold weather, without an aux blower motor.

[Jack Olsen]

I have one of the plug-in electric heaters. They're worthless, IMO. I'm also planning on headers. If you can't fit the Webasto gas heater (which can't coexist with AC), then heated seat covers might be the only way to stay warm.

I hope someone out there has a brilliant solution for this, though. Everything I've tried so far has been a bust.

[hilandscott]

That is an important consideration: how much wattage would an extra heater require (and potentially heat lines, drain current from the system and overwork the alternator). Maybe those in the know could suggest an upper limit on wattage for the 911 alternator (running headlights, stereo, and rear defroster simultaneously).

The plug-in heater was not even on my radar screen, as I am hoping to defog the front glass. I'm betting I'll be warm enough in the cabin, so Webasto or heated seats would be a luxury that I'm not interested in (yet).

In addition to the wattage issue: would it be more feasible to plumb into the air intake from the dash side or via the front hood area?

[Bill Verburg]

ssi's will provide plenty of heat and are true headers, B&B are also headers with heat.

------------------
Bill Verburg
My Home Page My Pelican Gallery page My Porsche Owners Gallery Page

[hilandscott]

True, Bill, but SSIs will set one back $800 even on a good day. A set of Bursch headers is closer to $300. I also have info from more than a few sources now that the Bursch (aka Euro) headers provide even better torque improvement (over post-74 exhaust) than SSI.

Hence the question of getting more than adequate heat to the front. As my '78 Euro is stripped of both heater blower and smog pump (and related conduits) I really don't see how adding the flexible lines to the heat exchangers will provide moving warm air to the flapper boxes in a passive manner.

Thanks, John

[wckrause]

I see, I thought you were just missing a blower motor and a few hoses.

Can I suggest a warm pair of gloves?

[Bill Verburg]

A few of the local racers use Bursch I have never heard any claims of superiority other than weight and cost. Ssi flows very efficiently, they are smaller diameter than Bursch and so are more suited for lower rpms(<7000) and smaller displacements(<3.4 liters).

The engine fan will move plenty of air through the ductwork at any speed above idle. The best heat I ever had in a 911 was in my 72 with no engine mounted fan and old style heater boxes, next best was ssi w or without engine mounted fan. I believe that the only reason the engine mounted fans were adopted was to equalize heat between low and high speed conditions. The older system would fry you at speed then freeze you when coming to a stop.

[Joeaksa]

Bill is correct, my 72 model would bake you out as long as you could make headway, but when you sat in a traffic jam, you were done for! The motor driven fan has enough extra air to keep you toasty up front as long as there are no leaks in your hoses, valves and the heat exchangers are in good shape.

The main problem is keeping the windshield clear, especially when its humid and cold. Only time the heating in my 85 is better than the older model is at idle and then I do appreciate the additional heater fan to keep the car warm until I can get moving again.

[BRAINIAC]

Why not find a sheet metal fab. guy and have him fabricate heater boxes around your headers?

[Bill Verburg]

Only fab some home made heater boxes if you are sure they will rust through before the inner pipes. CO poisoning is insidious.

------------------
Bill Verburg
My Home Page My Pelican Gallery page My Porsche Owners Gallery Page

[BRAINIAC]

Whew! Bill, thanks for the reminder. Very good point! I wouldn't put boxes around non-stainless headers.

[89911]

Bursch headers will set you back $300........about every 3 years. That when they will need replaced because of rusting or cracking. Stick with stainless steel.