Webasto Air Heater Installation

[MikeD930]

After years of having no heat (no heater box on custom headers) and not having an option to add typical aftermarket headers with heater box due to the 993 twin distributors being in the way my 930 finally have heat!! I added a gas version Webasto Air Top 2000 air heaters. I was lucky to find this new heater on ebay otherwise I would have to go with diesel version air heaters. I would only consider a well known brand heaters such as Webasto or Eberspacher heaters...not the cheap chinese heaters.

Although there are several folks here who have installed air heaters in the area of a smuglers box my 930 has an electrocooler AC compressor within the smuglers box. I looked for other areas to place the air heater. I decided to place the air heater in front of the spare tire/fuel tank. I know this does not sound safe but the portion of the heater next to the tank stays cool whereas the hot portion of a heater is next to the spare tire. A fire resistant insulation is placed between the air heater and spare tire/fuel tank. I could relocate the AC compressor to the front and place the heater on top/within the smuglers box which would be a last resort if needed. I'd rather have a lighter weight heater at the front than a heavier AC compressor. Be forewarned that my setup would not work with a stock car jack and its jack mount in place. I removed the footwell blowers and interior temp sensor/fan assembly from behind the ashtray. The Webasto controller is mounted next the steering wheel. I will remove the rest of the autoheat controller and flapper boxes in the future.

I went for the first test drive with this air heater yesterday and by luck the outside temp was around 25 deg F which I had never driven my 930 this cold. The air heater brought in heat but at any speed above 15 mph cold air were splilling into the cabin through the cold air vents. So before the second test drive on the same day I closed off the fresh air intake to the electrocooler blower making the electrocooler AC 100% recirculation. It was a success...no more cold air coming in through the vents and my cabin remained toasty no matter what speed I'm going. The amount of heated air blowing in stayed constant independent of the engine's rpm. The bonus is that I can run the air heater without turning on the ignition or engine.

Here are the photos of the install (first tested the air heater in my garage without any insulation to check for leaks and see which component gets hot then installed insulation).

Custom made air heater frame for mounting the air heater to the car (mounting plate not shown)




Heater mounting plate during test fitting




Heater test fitting to determine best location






Installed air heater at front



added insulation




Installed hot air ducts at blower



added insulation




Air Heater fuel pump and fittings




Air heater fuel Line and electrical routing




continued next posting...

[MikeD930]

Air heater mounting




Air heater exhaust




Air heater controller

[gsxrken]

I’ve always heard of these but never seen one. Thanks for posting. Doesn’t look like a trivial project!

[zakthor]

Cool!

It does look complex. I have some basic questions:
- the fuel and power are both right there in the frunk. Seems like the only 'external' that should be needed is an exhaust to outside, heated air could be recycled from cabin?
- why do fuel line stuff under the car?
- lot of flex hose, why cant you mount the unit closer to the exhaust and cabin air intake?
- what webasto model number?

Thanks!

[MikeD930]

Originally Posted by gsxrken

I’ve always heard of these but never seen one. Thanks for posting. Doesn’t look like a trivial project!

It was not an easy project!

Originally Posted by zakthor

Cool!

It does look complex. I have some basic questions:
- the fuel and power are both right there in the frunk. Seems like the only 'external' that should be needed is an exhaust to outside, heated air could be recycled from cabin?
- why do fuel line stuff under the car?
- lot of flex hose, why cant you mount the unit closer to the exhaust and cabin air intake?
- what webasto model number?

Thanks!

Yes...the heated air can be recycled from the cabin. I tried that setup but found that the amount of heated air flow from the heater was reduced so I opted not to use that setup. I may give it another try.

The fuel line was taken directly from the fuel hose between the fuel tank and fuel pump under the car. It goes directly to the air heater under the car. See pic below.

I wanted maximum luggage space and I do not want any portion of the hot exhaust pipe to be exposed within the front trunk. So there's three locations for the air heater...best location would be within the smugglers box, second best on top of the smuggler box lid, third best is at the front where mine is set up. I could not place the heater on top or within the smugglers box since there's an electrocooler compressor in it. See pic below. I'm not sure what you mean about mounting the unit closer to the exhaust?

Webasto Air Top 2000 STC B (gas version)


Bottom of heater below front trunk




AC compressor in smugglers box

[zakthor]

Originally Posted by MikeD930

It was not an easy project!





Yes...the heated air can be recycled from the cabin. I tried that setup but found that the amount of heated air flow from the heater was reduced so I opted not to use that setup. I may give it another try.

The fuel line was taken directly from the fuel hose between the fuel tank and fuel pump under the car. It goes directly to the air heater under the car. See pic below.

I wanted maximum luggage space and I do not want any portion of the hot exhaust pipe to be exposed within the front trunk. So there's three locations for the air heater...best location would be within the smugglers box, second best on top of the smuggler box lid, third best is at the front where mine is set up. I could not place the heater on top or within the smugglers box since there's an electrocooler compressor in it. See pic below. I'm not sure what you mean about mounting the unit closer to the exhaust?

Webasto Air Top 2000 STC B (gas version)

Thank you! I'm glad I asked.

[MikeD930]

I added SCAT ducting between the air heater intake and cabin ducting for the recirculation setup. I determined that the amount of hot air coming into the cabin was adequate so I'll retain this setup. At one point during a drive yesterday with a side window slightly cracked open while running the air heater (it got a little too warm inside hence opened window) I came up to a old diesel p/u in front of me which spewed diesel exhaust. So I closed the window but kept the heater on. Due to recirculation setup no diesel exhaust were coming into my cabin. So this passed the test.

[krasuskyp]

MikeD! Entirely badass setup - nice work there... well done!

I hate that my heat doesn't work - have heater box headers but suspect my center control and footwell blowers etc need attention 8 /

[MikeD930]

Thanks Paul!

Regarding your heater...I would yank the footwell blowers, put in SCAT or alum ducting and convert the autoheat controller to manual levers if the controller/blowers are inop.

[fourblades]

Nice job on the install. Can you use heat to defrost the windshield? Not sure how the air routing in these cars works.

How well does the electric AC work?

John

[MikeD930]

Yes...the air heater can defrost the windshield. These cars has blend valves that divert cold air to the windshield or front vents and heated air to the windshield or bottom vents. Although my car has electric AC and air heater I changed the setup of the recommended ducting for the electric AC. I set mine up so that none of the heated air goes into the electric AC blower.

The electric AC works great when the humidity and heat is not too high. It's not as good as the upgraded AC system though. At extreme humidity/heat the vent temps would be in the mid 40's to low 50's degree F for the electric AC whereas it seems the upgraded AC would be in the mid 30's to upper 30's degree F.

[fourblades]

Ok makes sense.

I am thinking of getting all Griffith upgraded parts having a black car and living in Florida.

John

[MikeD930]

I went on a 1k mile round trip down south in Arkansas over the last weekend. On the first morning the outside temp were in the 40's. The heater worked great. The average outside temp increased daily then it reached the mid 80's. At that time the electric AC did its job. So for my first time my wife and I remained comfortable without resorting to blankets to stay warm.

[MikeD930]

Forgot to include latest pic of the front trunk...