From what I remember, there wasnt a vacuum line. Is it the breather tube from the distributor? If its the breather, it should connect to a bung on new RS style tube.

 

Are we speaking of removing the fan in the engine compartment?
With the electric fan in the engine compartment removed and the plumbing bypassing it, the engine's blower in conjunction with the fans in the footwells should probably produce some heat as in the old day of the 911.
What about the reverse flow on the 993 where the car uses the electric fan in the trunk to cool a hot engine that has just been shut off to reduce a heat spike in the engine? Is this feature important to keep intact?

 

What is the purpose of removing the heater fan in the engine compartment?

 

Cleaner look, accessibility, weight.

 

The breather tube (clear) must be connected to the RS tube that I know. There is a vacuum line connected to a vacuum actuator on heater/blower housing.

 

I remember about that now; I was thinking of some open vacuum line. I took the power connector, actuator, and that spring resistor thing and zip-tied them together neatly and out of the way. Havent had any problems so far.

 

For hose that have removed the heater blower and hooked up the internal fan still.


Are you still getting enough heat into the car on cold days? Anyone have a temperature rating on how cold it can get and the heater bypass solution still keeps up and warms the car?

Thanks Guys

 

I seem to recall the heat in my 86' was just fine when the car was running with the engine over 2000 RPM. Sitting at a traffic light in Cleveland winters the heat would fall off significantly. I bet the heat works fine as long as the car is moving. Stuck in traffic, not so much.

Andy

 

No problem daily driving in temperatures down to 30 degrees. The volume is a bit less than with the rear blower, but doesn't seem to prevent heating up such a small cabin space.

 

Very interesting! Thanks for sharing the info.

-Luccia

 

Would this modification work in a 964? Even though the black box looks different in the 993, I found the blower relay in the 964. Can I just put 964 610 184 00 in place, remove the 30 amp fuse, and go from there?

 

I'm in Arizona and I have yet to have my heater blower switch on during a hot day. I even did a few tests and sent in my CCU because I thought something was wrong. (I posted on this a while back). Everything working normally. I believe it really only switches on if it is a hot day and you are in bumper to bumper traffic or are pushing the car really hard.

I've thought about getting the RS Duct, is there is one preferred? I really don't care about carbon fiber bling.

 

I never realized you could make this type of change and still have good heat/AC. When I have run without the engine compartment fan heat and AC never worked quite right. So if I jumper/relay some things I can have a cleaner look and keep heat AC? Fantastic! I hope the RS tube is still available. Anyone happen to have part numbers for the OEM plastic version? No need for CF bling.

 

Yep, I've got this stuff arriving from Sunset today:

964-106-403-02
Air Guide
$61.19

964-610-184-00
Relay
$13.51

993-211-941-00
Exhaust Duct
$193.47

I'd much rather be using the inconspicous RS duct than the silly carbon fiber aftermarket versions.

 

I used the ugly porsche duct too, and just installed this on my 95 this afternoon, it was a pita to connect to the fan duct. i would make sure you have thick, non pointed, assortment of picks handy to pull the lip of the duct around the tube, its a bear. good luck!