How do you backdate heat & keep AC?
 

I've seen some threads on this but not a lot addressing this in detail (AC version).

I would like to get an idea about:
1. How hard this is
2. How much it will cost
3. What kind of gains it will produce

Also, pictures would be nice (with AC).

Sorry, no pics but a search will turn up many. I backdated the heat in mine and I am so glad I did. I have all the original AC equipment in place, no problems there.

Well worth it... Cost is about $100-$200 depending on new or used parts. Gains are minimal. Best part is you clean up the engine bay and get all that crap out of there.

Although many backdate the heat and remove the AC at the same time (myself included), each are totally independent upon the other (i.e. you can remove either and still have the other).

I guess my main question with this thread is, is there anyone out there that has made a right side plate with a outlet that goes directly down to the heat exchanger allowing the Ac to remain?

That's my next project starting in the next day or two.

Awesome, I'll be looking for some updates and pics!

After surveying where the right duct must fit under the A/C, I saw that at a minimum, my cross brace for my A/C platform would have to be reworked.

I used some ducting from http://www.aircraftspruce.com/menus/ap/ducting.html .

I have the ducts/tubing attached to the heat exchangers and into the egine bay. I gave not installed my new ducts on each side of the fan yet.

I stopped at this point because I wanted to test something. I have foot well blowers. Do I need added push for air at a cost of reduced air to cool the motor (not a big deal in the winter)?

Engine bay air is engine bay air the way I see it, whether it's pushed into the cab or pulled. I took a few drives to test, I haven't had heat since I have had this car (two winters). I have plenty of air blowing to all the vents and great heat. Unless I can find a downfall of this setup, I think I'll stay with it as is.

If I stay with it as is, I have a plan to even filter both in-lets.

We had to slightly dent my right side duct for the a/C bracket to fit. Everything else went together fine.

heat w/ac
 

Patton, You have the coolest ideas. I'm subscribed.

heat/ac
 

I found similar results when I removed my heater blower [I installed the left plate but never connected it] you still get heat in the cabin.

I'm going to further develop my current set-up. Therefore, I have a recently black powder coated (better than new) set of OEM air ducts (right and left) for those wanting use the engine fan for heat.

I'll list them with pics on parts for sale.

+1 kc911.....what am i missing? are the later cars that different from a '74? they're completely independent on a mid-year car for example. you can have a heater blower in rear or not and it doesn't affect the dealer-added a/c.

As mentioned above, it seems like it not that big a deal as long as you bang on the right side duct to fit under and behind the AC bracket. At least I hope not.

I posted this a couple of days ago.

http://forums.pelicanparts.com/porsche-911-technical-forum/328704-ssi-install-heater-backdate-experts-chime.html

Awesome. that is exactly the visual aid I needed.