DIY Exhaust Mod – Gain of 10+ HP!!!

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Update: I've driven the car a few more times and am very pleased with the sound. If I did it again, or opened the muffler back up, I'd probably go just a bit louder with a 3rd 1" hole, but I'm satisfied for now and worry that too much more would be obnoxious.
As is, it's definitely tasteful and sounds more like I feel a Porsche should sound.

Just do it!

[Jgkram]

PW,

When you say "opened the muffler back up" did you actually separate the halves? Your photos look like you just drilled through the shell and then through the internal pipes on each end. Also if you did not separate the halves, I assume that you would have to drill another hole in the top to access a second hole in the internal pipes, correct?

I really really like your stab at this modification as there are no external pipes needed for the bypass and therefore it looks much cleaner and is a MUCH more elegant solution.

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Originally Posted by Jgkram

PW,

When you say "opened the muffler back up" did you actually separate the halves? Your photos look like you just drilled through the shell and then through the internal pipes on each end. Also if you did not separate the halves, I assume that you would have to drill another hole in the top to access a second hole in the internal pipes, correct?

I really really like your stab at this modification as there are no external pipes needed for the bypass and therefore it looks much cleaner and is a MUCH more elegant solution.

Sorry, poor wording.
Yes, I only drilled a 1" hole in the muffler to gain access to the inlet pipes. If I pulled the muffler off again, I'd probably just drill through the patches I had welded on and remove them the rest of the way with a chisel. Because of their location, I'm sure I could access more of the inlet pipes (rather than drill more holes in the inlets, I'd probably just make the holes that I already made oblong).

Originally Posted by Boxtaboy

Neat trick you did there. I wonder if there's a way to get rid of the whine that you hear so prevalently on these early Boxsters as it's winding down from the up rev. In yours, you hear the whine as you rev up too. It's a feature I hear on pretty much every rev video of Boxster exhausts except a muffler delete like the one below, or a GHL muffler. My dansk exhaust exhibits very little of that whine, although I can still detect it a little. It must be the back pressure of the exhaust?

Muffler delete on Boxster:
https://www.youtube.com/watch?v=YbCwcWaJkGI

I have no idea, though I noticed that it's still there, too.