DIY Exhaust Mod – Gain of 10+ HP!!!

[chipmunk]

Originally Posted by 01BOXYS

I just want to clarify that you just need to punch a hole in the same position as Crios and Particlewave mention then using the drill bit step up to the size you want to achieve? You don't have to drill any further into the muffler than just the hole?

Just drill through the pipe - one layer only. This allows the exhaust to bypass several of the chambers. The bigger the hole the more exhaust bypasses and the louder it gets. Don't go bigger than 25mm or you get resonance.

[01BOXYS]

Great thank you for quick response! I plan on doing this mod tonight and can't wait to give my Boxster S a little more attitude.

[antny]

I did not feel like buying a corded drill to do this for mine so what I did is just used the long 1/2 inch drill bit and just used a hammer to punch holes. Took a little longer but with the welded oval tip and a cordless drill this was the easiest way for me to get the holes in there. No one will ever be low enough to see my holes are not perfectly round so I was happy with it.

[silver-S]

Can you turn the screwdriver 90 degrees and punch a perpendicular slot? I'm thinking if you get a + shape, the bit should setting into the crossing and drill. (Or, maybe, just use a Philips screwdriver?)

[chipmunk]

Have a look on this thread for the links to the YouTube videos I posted demonstrating the different sound for different hole sizes.

[aowolf]

I did this ~5 years ago on my 1999 and today I went to do it on my 2000 S. We drilled two perfect 3/4 inch holes and I can't hear any difference at any RPM. I still have my 99 so I looked in and it looks like I had pierced the center pipe in chamber three. As other have pointed out that seems more consistence with the PSE bypassing a lot of the Muffler.

Those of you who are raving about this did you pierce the center tube? I don't want to just keep drilling larger holes in the curved pipes if its not going to make any difference.

[10/10ths]

...who have done this mod, how about a progress report now that you have a few years with this mod under your belts?

Pretty please?

Thanks!

[BoxsterSteve]

Originally Posted by 10/10ths

...who have done this mod, how about a progress report now that you have a few years with this mod under your belts?

Pretty please?

Thanks!

I drilled 1/2" holes in mine. I have a mild snarl added to the exhaust note plus a bit more volume.
Not over the top by any means, just enough.

For anyone who has a hard time starting the drill bit, I used a hammer and a long shaft straight blade screwdriver to punch through the pipe first so the drill could bite and wouldn't wander all over.

[silver-S]

I drilled 10mm (3/8") holes in both sides of the muffler on my 2002 S. It increased the bass rumble, but didn't turn it into a snarling beast. I have gotten a couple of comments on this, but it's a subtle change.

[njbray]

I have 2x 3/4" holes and they didn't make much difference UNTIL I put on the 2nd cat delete pipes! Opened up the air and noise much better. No drone and a little grumble on the downshift!

[TypeA]

Did this mod today. My 02 exhaust tip is welded but with a $13 1/2" bit from Home Depot I managed. I like the effect but too much of a coward to go bigger than 1/2" without a reserve muffer on hand. I am sensitive to drone and so far so good but I do wish it was a bit louder.

[DWBOX2000]

Just wondering now that some time has passed, is everyone still happy with their choice of drilling out? Some other sites were saying it made the boxster sound more like a japanese car which is fine if that is what you want.

Thanks,

David

[silver-S]

Originally Posted by DWBOX2000

Just wondering now that some time has passed, is everyone still happy with their choice of drilling out? Some other sites were saying it made the boxster sound more like a japanese car

Yep, still happy with 3/8" holes. It doesn't change the sound a lot -- it just adds rumble, mainly. It's not going to wake up your neighbors or turn heads when you leave cars & coffee. It's a subtle change, but worth making.

[jintwert]

Do what everybody else told me I couldn't do cause it wouldn't fit....I installed headers and intermediate pipes from a 06 Cayman and the mufflers already had the secondary cats deleted. My Midas dealer cut and rotated the pipes a little for clearance with no issues. I vinyl ty rapped the wheel sensor wiring to the struts far from the exhaust..wa la! Still there. Sounds great and a steal for a $1000. Sounds way better than Fabspeed. I heard one and thought it sounds the ****************s!

[fridsten]

I'm considering opening up my muffler, enlarging the holes where the pipes enter, thus making what could pretty much be called an internal Pedro mod.


Drilling by the red arrows would allow the exhausts to follow the blue arrows into the outlet.

Would that work? It would be a fairly easy mod to make, provided you're able to weld or get someone to do it for you. It would also look completely stock from the outside.

[Ben006]

Originally Posted by fridsten

I'm considering opening up my muffler, enlarging the holes where the pipes enter, thus making what could pretty much be called an internal Pedro mod.


Drilling by the red arrows would allow the exhausts to follow the blue arrows into the outlet.

Would that work? It would be a fairly easy mod to make, provided you're able to weld or get someone to do it for you. It would also look completely stock from the outside.

It's a common mod that I've been told works very well. One or two 15mm holes.
You don't have to open the whole exhaust, just open a window on both sides.

[More]

Thread needs more pics for us 97 to 99 Boxsters. I need to see where exactly to drill the holes.

[professorman]

How long does the drill bit need to be?

[BoxsterSteve]

Originally Posted by professorman

How long does the drill bit need to be?

Check the first post... it shows what tools were used. It doesn't appear to be an extra long bit.

[silver-S]

I used 24-inch (60cm) drills. Anything shorter will not reach the spot that needs to be drilled.