Backdated Heat 79 911SC

[NickW21]

I know there are literally hundreds of threads on the backdated heat project, but I just wanted to confirm what parts I need. I've seen a million threads and read most of them, but there's just a lot going on there that they are sometimes hard to follow.

From what I gather, I need to replace the blocking plate on the right side of the shroud with this: https://www.pelicanparts.com/More_Info/91110632201PH.htm?pn=911-106-322-01-PH&SVSVSI=793&fs=0

I then need to switch out the plate on the left side of the shroud with one that will allow a hose to directly connect the heat exchanger to the shroud air output vs. the large connection to the blower. This part seems to be the correct one: https://www.pelicanparts.com/More_Info/93010632101V2PH.htm?pn=930-106-321-01-V2-PH&SVSVSI=793&fs=0

There are mixed reviews on these parts from PartsHeaven, but I cannot find anything that says there are better ones out there. I also know that my 79 SC has a smaller fan and shroud than other 911s, so I'm nervous that will cause even more issues.

A previous owner already switched out the stock heat exchangers for SSIs, so the current set of hoses already connect directly to the heat exchangers. I also know there are other aspects of the backdate, but none seem to concern me. I live in the Northeast and don't intend to drive it when it's cold. So poor heat when idling isn't a concern for me to get into attempting to make any tricky electrical mods that others have attempted to get more heat at idle speed.

Anyway, before I shell out a couple hundred bucks on parts that may not really fit my car does anyone have parts out there that you'd recommend, especially if you've done this modification on a 78 or 79 SC? Any other advice to offer? Thanks much!!

[luvndasun]

Im doing this now. Those are the correct parts that you referenced. I also saw the reviews that the fit was bad, especially for the driver side duct. Ive gotten parts installed without too much trouble. I havent inspected them to see how well they fit, ie are there gaps where I will loose heat. I havent started my car yet, as I cracked my distributor cap in the process.
Here's a link to a very good article and one of the installations described was on a 79.
https://forums.pelicanparts.com/porsche-911-technical-forum/937025-backdated-heat-tech-article.html

[Mark Salvetti]

I have this in mind as well. I've seen other threads where the parts from Patrick Motorsports were claimed to fit without any mods, even on the left side.

Can anyone comment on that?

Mark

[psychoideas]

Originally Posted by NickW21

I know there are literally hundreds of threads on the backdated heat project, but I just wanted to confirm what parts I need. I've seen a million threads and read most of them, but there's just a lot going on there that they are sometimes hard to follow.

From what I gather, I need to replace the blocking plate on the right side of the shroud with this: https://www.pelicanparts.com/More_Info/91110632201PH.htm?pn=911-106-322-01-PH&SVSVSI=793&fs=0

I then need to switch out the plate on the left side of the shroud with one that will allow a hose to directly connect the heat exchanger to the shroud air output vs. the large connection to the blower. This part seems to be the correct one: https://www.pelicanparts.com/More_Info/93010632101V2PH.htm?pn=930-106-321-01-V2-PH&SVSVSI=793&fs=0

There are mixed reviews on these parts from PartsHeaven, but I cannot find anything that says there are better ones out there. I also know that my 79 SC has a smaller fan and shroud than other 911s, so I'm nervous that will cause even more issues.

A previous owner already switched out the stock heat exchangers for SSIs, so the current set of hoses already connect directly to the heat exchangers. I also know there are other aspects of the backdate, but none seem to concern me. I live in the Northeast and don't intend to drive it when it's cold. So poor heat when idling isn't a concern for me to get into attempting to make any tricky electrical mods that others have attempted to get more heat at idle speed.

Anyway, before I shell out a couple hundred bucks on parts that may not really fit my car does anyone have parts out there that you'd recommend, especially if you've done this modification on a 78 or 79 SC? Any other advice to offer? Thanks much!!

I too, am in the process of backdating the heater ducts. And like you, read heaps of threads about how some were needed to be modified with a hammer to make fit. Down here in Australia it's even worse trying to source parts. I especially didn't want to shell out the money only to have to modify it when it got here. I decided to make my own. I've always dabbled if fibreglass so thought, How hard could it be?

The pic of the right side is finished. Well, as good as is going to get anyway. The Left side I only test fit tonight. It still needs one layer of carbon fibre to finish it off. Maybe I'll do that on the weekend.
The last pic shows the plugs and molds that I produced to get this far starting with the original. Lots of work.

So my suggestion is to buy the metals ones and fit them up by hand. Mine were a lot of work, but they do fit well with no need for sealing tape. Good luck, it surely cleans up the engine bay.

[JSZ]

Or you can build them yourself to ensure a good fit and finish. Here is mine which I completed when I went to ITB
New ITB's and EDIS system on my 911sc

Jeff