Homemade PSE version 1.0 done, behold the "Evan Sport Exhaust"! pics/vid/writeup =>

[dagdisco03]

This looks great I've been thinking of doing something very similar but now that you say not enough cow bell I'm thinking I may skip the valves and just drill a hole where I show it in this picture to go through the inner pipe and then just cover the hole in the muffler casing to keep the OEM look.

[evan9eleven]

Originally Posted by dagdisco03

This looks great I've been thinking of doing something very similar but now that you say not enough cow bell I'm thinking I may skip the valves and just drill a hole where I show it in this picture to go through the inner pipe and then just cover the hole in the muffler casing to keep the OEM look.

That will give you about the same effect I get with valves open. If I were to go that route knowing what I know now, I would probably drill that hole all the way through both sides of the inner pipe to double the flow into the outside chamber. While my mods sound good, if you heard this in person you would not be impressed. My wife even commented that she could hardly hear the difference, as did my indi shop. Thats a buzzkill for sure.

If you cut a big square out of the top of the outer chambers, you could work inside more easily. Then I'd just cut a big section out of the inner pipe, and finally weld your squares back in place. That might provide a good level of cowbell, but still not extreme since your bypass isn't going straight to the tips.

FYI all my piping is 1.5", so don't be shy with drilling big holes or opening up the bypass to allow good flow. Good luck!

[woodsman]

Fantastic info and pics-

[Meir]

this is very impressive.
i wanted to do that mode since the first day i bought my car.
i collected parts and information for over 2 years.
unfortunately i sold my car before getting to it. still have all the parts.
now that i have the 99, not sure if i will do it.
just one question. it took me a long time to find a vacuum operated valve.
i finally scored some from a BMW 740 and another set from 335i.
where did you get yours?

[evan9eleven]

Originally Posted by Meir

this is very impressive.
i wanted to do that mode since the first day i bought my car.
i collected parts and information for over 2 years.
unfortunately i sold my car before getting to it. still have all the parts.
now that i have the 99, not sure if i will do it.
just one question. it took me a long time to find a vacuum operated valve.
i finally scored some from a BMW 740 and another set from 335i.
where did you get yours?

There are lots of places to get the valves, actually. I got mine from Capristo in Germany as these are very high quality and the price was surprisingly less then some others I looked at.

Pierburg makes the valves for the factory PSE. Helical in the UK make inexpensive valves but they and their sales rep also don't return emails. Carnewal in Belgium can source nice valves as well (I can't remember who they get them from.) There is also an ebay seller that has them cheap, but to be honest I was put off by the way he answered any of his customers who complained. Capristo and Carnewal were both a joy to deal with.