1977 911s Newbie: Exhaust Opinion !

997GT3 · 04-24-2023, 11:12 AM

Hey guys! Been a member on rennlist for years and avid Porsche obsessed fanboy and avid owner also of modern GT3s.

Just acquired my first air cooled 911! It’s a 1977 911s. Currently has stebro headers and exhuast. There is an exhaust leak and the system is very old.

I have been in talks with M and K and my final thought is to buy their their headers and single exit Exhaust.

My question is this:

1) is the full header (no heat exchanger) and exhaust the best choice (or among the top) for power/sound/reliability/clean look ?

2) will not choosing/avoiding heat exchanger system effect resale value at all ? Aka does it really matter that I am removing the heat exchangers altogether or would the general consensus be to install SSis and the M&K muffler ? Will I have no heat in the car or bad CO coming into the cabin?

These cars seem to be strictly driven in nice warm conditions and my personal
Desire for heat is almost nill, but I want a final opinion!

I have searched, there is so so much info. Perhaps I missed it. I know it’s been talked about extensively but I can’t seem to find consensus on the topic.

Thanks for everyone and I hope to be welcomed in the air cooled community.

Also zimsparts, I tried emailing them and zero response for miscellaneous parts I need. Should I look elsewhere for miscellaneous parts ? (Wipers, hood/engine struts, interior trim prices, tubing, sunroof cables, etc) if anyone has the best contact for that, I would be greatly thankful!

Showdown · Showdown's Garage

I have a 77 and I went with SST and the M&K 2-in 1-out sport muffler and it was fantastic. No drone, relatively muted sound under about 3500-4k but a nice raspy note above. It was quiet enough that I could drive in the city and early morning around my neighborhood without pissing anyone off but when it was WOT it was awesome.

The 2-in 2-out mufflers are LOUD AF and drone to the point of making me queasy. Stick with a 2-in 1-out.

Headers vs heat exchangers is solely a location/preference thing. In the warm climates I don't think it makes a difference. In climates with cold it would be an issue but everyone is unique and it's not a permanent modification so it can be removed and sold later on if needed. Don't spend too much time worrying about the value of the car unless it's an investment. If you're going to drive it for fun and your own enjoyment, then do whatever you like.

As for miscellaneous parts- Pelican classifieds is a gold mine.

tdw28210 · tdw28210's Garage

Welcome. Zimsparts? Never heard of them...seriously. Just buy the new stuff from Pelican (our host here) and old stuff via the classifieds. As for headers vs heat exchangers I have headers on my cars, but I live in the Carolinas. I'd go headers and add the header heat pipe mod later if I felt later that I needed it. That just a simple pipe connected to the headers that allows some heat to be drawn into the cabin. Or get seat heaters installed. And M&K stuff is pretty good too.

jac1976 · 04-24-2023, 12:54 PM

I’m assuming he’s speaking of Zims (***********) in Bedford, and I’d suggest calling.

997GT3 · 04-24-2023, 12:58 PM

Thank you so much everyone for the assistance ! I truly appreciate it.

This is website that someone on rennlist referred to me.
https://store.***********/911-912-parts/porsche-911-930-912e-74-89/body-parts/

Also for the headers and aftermarket header heat pipe modification, would that simply bolt onto any header system easily including the M and K header system?

Is there any other system that would be suggested over and above m and K ?

997GT3 · 04-26-2023, 10:08 AM

Yes ! Zims is the store I am speaking of. Do you have any additional information on if they are reputable or not?

Also am I am able to installed the header adapter for heat on any system ?

Thansk for the info everyone

jac1976 · 04-26-2023, 11:22 AM

Al Zim has been in the Porsche game for ever. They are very reputable.

997GT3 · 05-02-2023, 07:46 AM

So I ordered headers and 2/1 muffler from M and K !

Does this mean that I am simply able to remove those heater hoses completely out of the engine bay ? So I simply get rid of them completely from the engine bay ? Aka the hose above the fan and to the left is the fan ?

997GT3 · 05-02-2023, 07:50 AM

Also with the header system, does that mean the heat system is completely non functional? Are there any other suggested parts that should be ordered that would close up heater openings or ducts in the engine bay and such ? Or should I get heat exchangers and adjust my order before they are built ?

jac1976 · 05-02-2023, 07:54 AM

Yes, remove the hoses. There are block off plates available.
Might remove the cardboard “engine pad” while you’re in there.

997GT3 · 05-02-2023, 07:59 AM

Hahah
Yes cardboard has been removed also lol

So all the hoses seen (red/brown), the other one to the left of that one and the one over top the fan all to be removed?

Would anyone happen to have a reference to the exact blocking plates required for this?

Thank you for the response !

darrin · 05-02-2023, 08:02 AM

If you live in an area where there's any possibility that your windshield might fog up (or any possibility that you might want heat inside the car, ie a chilly morning coffee run), my advice would be to consider adding heat exchangers to your order, as having heated air would make the windshield defroster system MUCH more effective. W/o heat exchangers, the heating system would be completely non-functional.

jac1976 · 05-02-2023, 08:03 AM

converting to headers... need oil hose solution

Right sided air duct.

Might try searching the forum or Google. A lot of information out there and readily available.

ADDvanced · ADDvanced's Garage

I wouldn't want no heat in a street car. IMHo those cheap exhaust with no heater boxes are tempting, but only appropriate for a track car, not a street car.

Furthermore, just because an exhaust system is old doesn't mean it is junk. Stebro was a very high quality exhaust manufacturer before they went out of business, I'm not sure why you think it needs replacing. If anything, pull the stebro system, get new gaskets, and get the stebro jet hot coated, but honestly from the pics of your engine bay it seems like your car needs a lot more than just that.

Nditiz1 · 05-02-2023, 08:45 AM

Welcome 997GT3.

ADDvanced is correct, spring for the heat exchangers. I am in the process of putting them on my racecar now. It's more expensive to do it later.

I know this thread was about exhaust, but you should also think about removing the 5 blade for an 11 blade fan AND back dating your heat and clean up the engine bay unless of course you are going no heat.

997GT3 · 05-02-2023, 08:49 AM

I appreciate the assistance I really do. Thank you guys. I am going to take the route of the SSi. I think it’s the best idea to retain factory look and heat. That being said do I buy thick or thin flange for my 1977 911s ? It’s a US spec car

ADDvanced · ADDvanced's Garage

Quote:

Originally Posted by 997GT3

I appreciate the assistance I really do. Thank you guys. I am going to take the route of the SSi. I think it’s the best idea to retain factory look and heat. That being said do I buy thick or thin flange for my 1977 911s ? It’s a US spec car

You need to measure what's on your car now. If you have long studs, you need thicker flange. You can get away with thin flange on long studs if you use some sort of spacers under the fasteners.

Keep the 5 blade fan, it's fine for a street car, and your money could be spent better elsewhere. After looking at your engine bay, you should really save up for dropping that engine to clean everything up, replace as many gaskets and hoses as you can get to, triangle of death, nose bearing seal, etc etc etc. It's a can of worms but then you're done for a decade or two. You can remove your engine by yourself with a $180 motorcycle jack from Amazon.

Why are you so adamant about getting ride of the stebro? Again, they made fantastic exhaust. What is wrong with it?

jac1976 · 05-02-2023, 09:29 AM

Quote:

Originally Posted by ADDvanced

I wouldn't want no heat in a street car. IMHo those cheap exhaust with no heater boxes are tempting, but only appropriate for a track car, not a street car.

First I’ve heard M&K referred to as “cheap.”

jac1976 · 05-02-2023, 09:34 AM

Quote:

Originally Posted by ADDvanced

Why are you so adamant about getting ride of the stebro? Again, they made fantastic exhaust. What is wrong with it?

While I’m more than happy with the M&K exhausts that I have run and don’t want to talk you out of it, ADDvanced is asking you the right questions. Stebro was/is quality, is period-correct and functional. You’ll have plenty of opportunities to spend money on this car.

997GT3 · 05-02-2023, 09:46 AM

I have to lift the car properly to investigate the underside of the car but I know that the current heat exchanger/exhaust does have a hole in the system. A large one. So once lifted I can analyze the car.

I guess once the engine and transmission are removed off the car, as I do plan on doing a full restoration, I was told that “Hunter motorsports” is the best place to send the motor to in Ontario canada.

Are there any other suggestions as to the best shop to restore the motor to fix all the issues with it ?