DIY Exhaust Mod – Gain of 10+ HP!!!

[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.

[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.

[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.

[tommy583]

https://www.youtube.com/watch?v=PO9l-X4eUOk This guy made a great how / before and after video. He even gives a shout out to Particlewave

[geetee]

2ndary cat delete and 2x 1 inch holes. No drone but still too quiet. I might go 2x 1.5 inches or maybe 2 additional holes....

[particlewave]

Originally Posted by tommy583

https://www.youtube.com/watch?v=PO9l-X4eUOk This guy made a great how / before and after video. He even gives a shout out to Particlewave

Ha! That's funny

I did this mod at the same time that I de-snorkeled and I thought the increased sound was nice, though mild. I'm now convinced that the muffler mod did little or nothing at all, as others have reported on the 2.5, and the increased sound was primarily from the intake.

I can confirm that the 2.5 muffler on my '99 is full of sound deadening material, rendering this mod virtually pointless.
I might crack it open some day to see what can be done.

[particlewave]

Or maybe all of the pictures of opened mufflers have just had that material removed before the picture? Can anyone who has opened one confirm or deny?

Edit: I went ahead and enlarged the holes from 1/4" to 3/4" and it did increase low end rumble, though not as dramatically as I'd hoped.

[heymanwatchthis]

Wonder what Crios mod is like if you add the Pedro Sport Exhaust mod?

[geetee]

I'm finally happy with sec. cat delete. 2 holes each pipe. 1.5 inch and 1 inch holes on each side. No drone and decently loud. 03 2.7

[particlewave]

I'm going to go right through the top of the muffler and into the inlet pipe with one or two 1" holes.

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.

[tommy583]

Originally Posted by heymanwatchthis

Wonder what Crios mod is like if you add the Pedro Sport Exhaust mod?

I sold a crios modded muffler to a buddy who sent it to Fister. They do a mod similar to the Pedro exhaust. I don't know if they closed the crios holes back up or not, but it sounds pretty awesome now.

[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.

[The Radium King]

Originally Posted by particlewave

I'm going to go right through the top of the muffler and into the inlet pipe with one or two 1" holes.

i wonder if you could go in via the entrance pipe to drill the holes - similar to the crios mod?

if you do as you say, perhaps a couple of 3/4" knockout plugs to fill the hole - no welding required, do it while the muffler is in the car?

[particlewave]

Originally Posted by More

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

I'm not completely convinced that it does anything on the earlier mufflers because of the sound deadening material inside.

Originally Posted by The Radium King

i wonder if you could go in via the entrance pipe to drill the holes - similar to the crios mod?

if you do as you say, perhaps a couple of 3/4" knockout plugs to fill the hole - no welding required, do it while the muffler is in the car?

I will definitely look into this. It will be after the 1st of the year before I get to it. If I can't get at it from the inlet, I'll go through the top (don't want the plugged holes to be visible from the bottom).

[More]

Any 98ers on here that have made this modification?

Does it work?

[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!

[particlewave]

It's "voilà", lol (parlez-vous français?)

Only $1000?
Glad you like it, but that's crazy expensive. You could have had bypass pipes bought and installed for less than $200.