Rod Handsfield

I have been offered an X-pipe for my '91 S4. It is unused but upon examination it looks different from the type I've seen pictured on this forum. The 2 pipes are joined by a short length of pipe rather than directly with with a common elliptical weld. What type of x-pipe is this? Does it function as well as the others type? thanks.

aggravation

I took a pipe like that off my car and replaced it with an X pipe that I got from Roger at 928's r us, I noticed an improvement going to the 'proper X' type.
I did the switch after I had removed the old supercharger and had returned the car to stock condition while I made a lot of repairs on my car. I wanted to know what a stock S4 felt like before I installed the new supercharger and remember thinking at the time that the X pipe was definitely an improvement.

cold_beer839

Sounds like an H-pipe. Can you post a pic?

Rod Handsfield

Yes, it is an H-pipe. Is the performance improvement similar to the X-pipe or is it crap?

cold_beer839

If you are spending the money and turning the wrenches, make it worth you time and money and get an x-pipe.

ZEUS+

The H design requires the gases to make a sharp 90 deg turn which decreases the effective rpm range where the X helps. It does not have the scavenging effect like an X pipe.

ROG100

What Zeus said - the H is old technology while the X is new ish 8>)

ew928

The factory S4 exhaust is an 'H' type exhaust.
But with twin cats.