Exhaust Layout

[pmajka]

do the 3.2, 3.4 and 3.6 engines have the same layout for exhaust at the Heads???

Background...

Car 88 911
I have a 3.7L Andial motor that was punched out of a 3.2

I believe the headers are stock, the 2 into one out the left side.
am considering some exhaust upgrades (true duals) and wondering if newer engins have larger header tubes?

Do you see where i am going here....

pushing 3.7L of ***** down a 3.2L pipe.

[Bill Verburg]

Originally posted by pmajka
do the 3.2, 3.4 and 3.6 engines have the same layout for exhaust at the Heads???

Mostly, the 993 passengers side side flanges are rotated 90&deg from all earlier version. If you use oem 993 headers on your engine it's easy enough to do.

Originally posted by pmajka

and wondering if newer engins have larger header tubes?

Yes, they do. For a 3.6 or 3.7 street motor you will want ~1 3/4" primary tubes.

Your cheapest option is oem 993, if you want to spend more B&B headers but not B&B mufflers

[pmajka]

thanks..

how about SSI headers?

[Superman]

There are at least a couple of styles of 993 heat exchanger flanges, and Dave at Triad makes a final exhaust to fit either. The stock 993 heat exchangers are a good alternative, particularly now that a good muffler is available.

[Bill Verburg]

Originally posted by pmajka
thanks..

how about SSI headers?

SSI has 1 3/8" primaries way to small to work above ~4500rpm

[Bill Verburg]

Originally posted by Superman
There are at least a couple of styles of 993 heat exchanger flanges, and Dave at Triad makes a final exhaust to fit either. The stock 993 heat exchangers are a good alternative, particularly now that a good muffler is available.

There is one and only one style of flange at the head. There are 2 styles at the header/cat interface, Bischof and Gillette

[JeremyD]

I have 964 B & B headers on my 3.4 - it breathes pretty nicely

[Superman]

Originally posted by Bill Verburg
There is one and only one style of flange at the head. There are 2 styles at the header/cat interface, Bischof and Gillette

Yup, those are the two flanges that Dave can accommodate. Gillete and Bischof. Apparently, stock 993 heat exchangers are good performers, and they are widely available. According to my understanding.

[Steve W]

About 2 or 3 years ago, I spent almost 10 hours programming an Andial 3.7 with a laptop, air/fuel analyzer, data logger, and can tell you, SSIs will severely choke off the top end, however your stock exhaust is choking it even more. Consider a properly sized set of headers and a good muffler.