Aftermarket exhaust

[Sammyj]

ill Just report on the progression of my car. I bought the car with a modified intake. The stock intake tube was replace similar to the Pedro mod. The first thing I did was de-snorkel. That gave the intake more roar and you could not even hear the stock exhaust. I then bought the cheap $250 dollar eBay muffler. It was louder and sounded good except on the freeway it had a loud resonance around the 3k to 3.5k range. I later added both cat bypass pipes and a k and n filter and the car not is much quieter at 3k on the freeway but overall sounds great. I’m guessing if you still had resonance you still had the pre-cats in your headers. Again I’m just reporting my experience with my 98’ 2.5 boxster.

[maytag]

Originally Posted by Sammyj

Again I’m just reporting my experience with my 98’ 2.5 boxster.

Mine is an '03 S (3.2).
Yes, I still running the stock manifold with the pre-cats. The secondaries are gone though.
My resonance is from around 2200 to 3k. But I live with it. ;-)

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[itsnotanova]

The 986 muffler is restrictive as it uses tiny tubes internally. It's also a boat anchor at 33 lbs. I believe the Chinese muffler drone can be fixed by welding in a crossover pipe. I think someone on here did that. I built my own using pieces from a 987 muffler. Lost 16 lbs and flows much better. With aftermarket headers and no cats, it has just the right sound with no drone. The 987 muffler has the same internal size tubes as the 996 exhaust.

[Robert986]

Originally Posted by itsnotanova

The 986 muffler is restrictive as it uses tiny tubes internally. It's also a boat anchor at 33 lbs. I believe the Chinese muffler drone can be fixed by welding in a crossover pipe. I think someone on here did that. I built my own using pieces from a 987 muffler. Lost 16 lbs and flows much better. With aftermarket headers and no cats, it has just the right sound with no drone. The 987 muffler has the same internal size tubes as the 996 exhaust.

That sounds really interresting! Care to show & tell?

[itsnotanova]

Woody's build thread
The exhaust modification starts with post 192