Bursch Catbypass vs Euro Premuffler

[yama1]

Any advantage to one over the other. The euro muffler is the stock Gillet on a Euroversion car.

I would think they would have the same amount of flow roughly. I didn't realize I already had the euro muffler until I removed it and bought the Bursch. Someone just kick me already. I assumed a cat......The unneeded labor I did and gasket/bolt replacement probably is my guess.

If so - I will sell the Bursch if no real difference.

Thanks

[SpeedracerIndy]

The euro premuffler supposedly yields more HP than the bypass pipe due to being a tuned expansion chamber (which promotes scavenging??).

There are several posts about it in the archives. If you do a search you'll find a more official explanation than I am able to offer.

I sold my original euro gillet pre muffler for a good price a year ago. For around the price of a new Bursch bypass pipe if I recall correctly.

[911st]

Word has it that Bruce Anderson had a conversation with someone that the euro premuffler showed a few ponies. Never have seen any confirmation or anything that he had written confirming this.

I do believe it makes more HP than an old cat.

The advantage to a pre muffler I suspect is more to keep the sound down to meet most countries sound requirement.

However, I did not notice much difference in loudness on my 3.2 when I took the cat off and ran a bypass with a stock muffler.

I mostly believe the premuffler and test pipe are the same on the HP front until I see a reputable back to back dyno test that says otherwise.

It could be possible that the opposite is true if Porsche thought to come up with the pre muffler to maintain the same tune as a cat so it would not have to come up with another chip to accommodate different state of tune. Probably not the case.

Don't most mufflers make more back pressure than straight pipes?

The 3.2 dose respond better to exhaust changes than most cars as they tend to run on the rich side and a better exhaust not only reduces back pressure but puts the 3.2 at a better Air Fuel Ratio in the upper rpm range.

Having said all that, many believe the euro pre muffler has special qualities and makes more HP than a straight pipe.

[yama1]

Seems to me the Euro muffler was tuned a bit over the straight pipe. The Euro is pretty much a straight pipe within another straight pipe or chamber. Most OEM's make the chambers for a number of reasons from EPA, Tuning, Exhaust temperatures, Sound, etc. etc. But like you say, to my knowledge, there is no data to really show the difference back to back.

I will put the Euro back on as that keeps the car more original with no performance drop.

The Bursch will be posted soon for another fellow pelican.

Thanks for the concurring comments guys.