I've got my 1981 torn apart again for some seal work. I was dropping the Y pipe to check the cat and possibly test pipe it to see if it made any noticeable difference. Whats the consensus of replacing the old cast manifolds with the newer tubular?

Is it a direct bolt on?

Anyone have a set laying around?

 

Dump the crappy cast iron manifold and get a set of 85/86 exhaust manifolds.
Think Stan Shaw may have a set, and I'm sure 928Intl has them.

 

You want the 85-86 manifolds. It is a direct bolt on, but your cats will no longer fit as lenghts are uneven on the new maifolds. If you have inspections, it may be a bit of an issue. You could always do what Tony did and put some cherry bombs on there and make them "look" like cats.

Let me ask you this... have you take the old manifolds off yet? Any problems with the studs breaking? Did you do this with the engine in the bay? I ask because I'm getting ready to do this myself and was just curious about what I might be getting into... Thanks.

 

John,
thanks.. since Stan is local, I try to contact him (if I can find his email)... Do you know if you need the RRFPR to get any benefit from the upgrade?

Andrew,

the only inspection for my year is a visual check of Cat presence.. I'm fairly sure mine is at least partially plugged thats why I opted to drop the Y pipe from the start. And no, I don't have the old manifolds off yet. I can't even seem to get the Y pipe off... the nuts are off the studs but the flange is rusted solid around the studs and the Y pipe won't budge. I likely have to drill the stud/bolts out just the get the Y pipe off. If I go that far, it may make sense to swap the manifolds instead of messing with the flange stud/bolts.

 

I don't have any of the '86 manifolds hanging around, sorry.

The manifolds are a direct bolt on to the heads, but on the drivers side, the exhaust pipe will need to be lengthened (if I recall correctly). Any exhaust shop that can bend pipe should be able to do it without a problem.

If you want a catless exhaust with a single borla muffler in it ready to be bolted on, I do have one for sale. I had the exhaust on my '80 with the manifolds you want from an '86/'86, but have now gone to headers.

 

Thanks Stan... I got your email too.

about 2 weeks week ago, there was set of these '86 manifolds on ebay. They only got a couiple of bids with the highest being $67 (I think they had a $250 buy-it-now option). Was that anyone here?

 

Do the 85/86 manifolds have an EGR provision on them?

 

I got a used set off 928intl a while ago (after kicking myself for missing a fairly cheap set on ebay). I also swapped to an S4 cat which was welded in place of my (missing) euro front muffler. As Andrew said, they had to lengthen the cat on just one side...and apparently not all shops are comfortable with modifying a cat.

However, the first chance that I can swap the cat for an X-pipe, it's gone.

 

Flint,

did you notice any difference with the new manifolds?

 

John,
Just seat of the pants, but it seems like I've gained in passing power, while I may have dropped in off-the-line. But, I befiore I switched to the dual cat, I had a single 2-1/2" cat from an early US model welded where the original dual-exhaust Euro muffler was supposed to be (presumably done by the importer). The rest of the system was dual, except for that single bottleneck.

 

stan, what kinda borla muffler did you use on that setup?

 

When I bought my '8o Euro S in '89, it had a Borla SS exhaust, no cat, with on large muffler, and one smaller one near the rear. Both mufflers had two 2.5" pipes in and out. When I put the fuel cell in, I dropped the rear muffler, as it was in the way.