Weissach1982

I'm just posting topics like crazy here.
Since I recently stated in one of my other posts I mentioned adding 85-86 exhaust manifolds on my 82 car. When my motor was being rebuilt and my stock exhaust manifolds were off..my porsche mechanic and I put the stock exhaust manifolds up next to the 85-86. They didn't seem like they would work because there was a gap when you put 85-86 manifolds on the head. Now, I've heard of it being done with great results acting as a header, but i'm clueless on what kind of modifications would need to be done in order to put those late model exhaust manifolds on my car. Any body that can help?
Thanks,
Cory J.
82 weissach

Flint

I am also anxious to know this, as I'm currently negotiating for a set of S4 manifolds. (I'm also adding an S4 cat..hehe).

Weissach1982

Would anybody know what kind of modifications have to be done?
Cory J.

Richard S

The 85-86 exhaust manifolds will fit on the earlier cars, however I have heard that the catalytic converter will not bolt up correctly.....you will have to lengthen one side to get it to mate up with the exhaust manifold. I have not done this mod, but others have and it worked for them. You can search for this same topic posted several months ago.

Rich.

sparks

Cory J. - I am also going to do this mod to my '81. You have to lengthen one of the pipes to the cat. I am thinking of up-grading the cat to the '85-'86 version. It would offer less exhaust flow restriction than the converters our cars have because of the "Y" junction at converter inlet. Has anyone out there done this with a "85-"86 converter?

Flint - The S4 manifolds are a 3 bolt configuration, and would require much fabrication to mate to the 2 bolt heads. I know because I was going to use S4 manifolds( found them cheep and plentyful). I don't know if a '84 Euro has 2 or 3 bolt configuration, but should be looked at prior to getting them.

Richard S

Euro exhaust manifolds are the same as the early US....ugly cast iron. You would want only the 85-86 US 2 bolt manifolds. It would be easier to modify the pipe on the cats than to cut and lengthen the manifolds, and I agree that an 85 cat would be a good upgrade.

Rich.

Flint

So...hows an 85-86 cat compare to an S4?

Lizard928

the 85 and 86 cats and exhaust is different

Weissach1982

I'm not worried about cat hookin up to the manifolds..i'm wondering which 85'on exhaust manifold will bolt directly up to my head. If there are modifications needed, does anyone know what has to be done to hook them up to the head because on here you have mentioned that there are 85' on 2 bolt exhaust manfiolds and 3 bolt exhaust manifolds..which car manifold is direct bolt on and what years do they come off of?
Thanks,
Cory J

Richard S

85 2 bolt manifolds will work, I think 86 is also 2 bolt but I'm not positive, 87 and up are 3 bolt. No modifications are needed to put the 85 2 bolt manifolds directly to your heads. (Disclaimer...I haven't done this, but others have and I'm just repeating what they have said...I am also interested in this mod in the future)

Rich.

Randy V

I'm not sure about the manifold, but I did install an exhaust sytem from an early '86 on my '79 for improved exhaust flow.

The '85 and early '86 exhaust setup is routed the same way as the earlier model years - but rather than a 2 pipe merge into 1 pipe at the cat like the old cars, it uses a 2-pipe cat, with 2 pipes to the end of the exhaust system.

Jim bailey - 928 International

the two bolt 85-86 tubular manifold with clearancing the stud holes slightly bolts to the 16 valve head .....BUT the ports on a 32 valve are centered and the ports on the 16 valve are staggered since the same head fits either side . The 16 valve manifolds are different lengths . When you put the 85-86 manifolds on a 16 valve no stock cat will fit you must move the three bolt flange (manifold to down pipe) forward on one side and backward on the other . You can however switch any and all cats as long as you have the original stock exhaust manifolds on the engine (ie 16 valve on 16 valve 32 valve on 32 valve) As mentioned before the 87 > manifold has three studs at each port and will not work for a 16 valve conversion .

Weissach1982

Jim-
So basically the 2 bolt 85-86 manifolds will fit with modifications on the tubes to make them match the ''staggered'' port or no?, I'm not worried about a cat..i have that problem fixed. I was just curious to know if there would be major port gaps to where the 85-86 2 bolt manifolds would fit against the 16v head and what modifications would be necessary to mount them.
Thanks
Cory J.

Jim bailey - 928 International

Cory they fit .......port spacing is the same

byrdman454

Resurrecting this old thread.

I am getting ready to put the 85-86 manifolds on my '84 Euro. Which exhaust gaskets do I buy, the older verson (-'84) or the 85-86 sealing rings?

Thanks