hockenheimr

I am doing a complete rebuild and upgrade to the 3.8L.

I purchased a used 993 complete exhaust for pretty cheap....guy just wanted to get it out of his garage.

I know that the flanges are opposite on one end, but someone said in a post that the 3.8L cylinders can accept both side....anyone confirm this? I am buying the Mahle parts.

And other then the flange issue, is there anything else blocking me from just bolting this on?

Thanks in advance! CheeRS

Bill Verburg

The exhaust manifold bolts to the heads, 993 heads have a dual pattern which can accept either earlier flange orientation or 993 flange orientation.

The right side 993 header flange is oriented 90° from that used on 964 and earlier 911.

To use the 993 header w/ 964 heads the right side flanges will need to be rotated to suit the 964 heads

hockenheimr

Thanks Bill...and everything else just fits under the car like normal?

Bill Verburg

The additional issue is fitting mufflers, 993 has a rear mount transverse cat that feed 2 side mount mufflers which reside in the fenders, the n/b 964 fenders don't really have enough room for them, though I do remember someone stuffing them in there w/ what success I can't say.

Here is a pic of a 993 w/ cat bypass and stock side mount mufflers


Note the angle of the header exit flanges, that makes it difficult to plumb to a traditional rear mounted muffler, and the narrow fenders don't have a lot of room for sidemounts

crg53

If you use the complete 993 set up, with the cat across the back, where the 964 primary muffler is located, you will have to reroute the oil line that runs from the crank case to the filter housing, or it will get way too hot. To use the 993 mufflers is also a bit of a problem, but can be done. You have to move the supports for the rear bumper side pieces, but no big deal. And of cause the cut out for left side exhaust tip. Then their is the O2 sensor, 964 only have one, whereas 993 VR have four, if you have the 95 exhaust it may have the single O2 sensor plug in located where the pipes merge into the cat. Other than that, you should be good to go.

hockenheimr

Ok, this is really good info thanks guys.

Bill what tips are those?..that is exactly the look I want.

Bill Verburg

The PO put them on the car before I bought it, I seem to recall either FVD or Cargraphic and did see them in one of those places product lists