DIY Exhaust Mod – Gain of 10+ HP!!! - 986 Forum - The Community for Porsche Boxster & Cayman Owners

sd_boxster · 03-03-2009, 07:04 PM

Started this last night, finished up this evening on my '03 non-S boxster.

The oval tip comes off by removing one 13mm bolt.

I used a 7/8" tapered bit, so the holes I wound up with are quite large - 7/8" by about 1.25 or 1.5" because of the angle at which I drilled.

I have not had a chance to open the throttle up properly - rolling on my spare right now, as I picked up a nail on the way to work today - but once I get a proper tire on, we'll see how it sounds. It currently reminds me of the Injen catback I had on my Tiburon, which I loved dearly.

The best part about this 'mod': if you hate it, pick up a used Boxster muffler for $50.

clb0099 · 03-03-2009, 07:39 PM

are you sure that is true about the oval tip as my car is a '97 and i am getting from alot of people that it is welded on and not screwed on.. and i have looked at pictures of mufflers from different yrs and some have the bolt and some looked welded on

crios · 03-03-2009, 07:48 PM

Yours are welded on, you need to buy a long drill bit, but you should be able to do without taking anything off.

http://beta.sears.com/shc/s/p_10153_12605_00966164000P?vName=Tools&keyword=1/2+Drill+Bit

Quote:

Originally Posted by clb0099

are you sure that is true about the oval tip as my car is a '97 and i am getting from alot of people that it is welded on and not screwed on.. and i have looked at pictures of mufflers from different yrs and some have the bolt and some looked welded on

crios · 03-03-2009, 07:58 PM

1.5 inches, wow! You have to post some clips!!!! How does it sound just reving it in park?

Quote:

Originally Posted by sd_boxster

Started this last night, finished up this evening on my '03 non-S boxster.

The oval tip comes off by removing one 13mm bolt.

I used a 7/8" tapered bit, so the holes I wound up with are quite large - 7/8" by about 1.25 or 1.5" because of the angle at which I drilled.

I have not had a chance to open the throttle up properly - rolling on my spare right now, as I picked up a nail on the way to work today - but once I get a proper tire on, we'll see how it sounds. It currently reminds me of the Injen catback I had on my Tiburon, which I loved dearly.

The best part about this 'mod': if you hate it, pick up a used Boxster muffler for $50.

sd_boxster · 03-04-2009, 10:02 PM

Video clip, as requested.

There is definitely a difference. My tires are once again holding air, so I went for a drive. There is some resonance at ~2900RPM, but it is not 'drone', and it's only noticeable for a range of about 100 RPM either side of 2900. Most noticeable difference is at low RPM - just sounds a little meaner.

I like it. I paid $600 or so for an Injen exhaust that didn't sound appreciably better than this.

The drill bit cost me less than 30 bucks. Not bad, considering how many people I've seen drop a thousand dollars on an exhaust they wound up hating.

clb0099 · 03-04-2009, 10:21 PM

sounds awesome.. i got to do this mod.. I am just afraid that i am going to run into a problem since my exhaust tip is welded on and I won't be able to get the right angle with the drill bit. The extra long drill bit might work but not sure..

sd_boxster · 03-05-2009, 07:34 PM

I propose that Crios gets to name this mod - all cool mods have catchy names that sounds better than "I drilled two holes in my muffler."

Suggestions:

Crios Bilateral Exhaust (CBE) mod
Center Baffle Bypass mod
CTA exhaust mod (cheaper than aftermarket)

Others?

RandallNeighbour · 03-06-2009, 10:01 AM

CDM Crios Drillout Method

SD, this is a WONDERFUL idea! I'm so glad you thought of it. Crios deserves to go down in history as the guy who came up with a totally cheap and easy way to make a factory muffler sound better without removing much of anything to do it.

I may just try it on my non-S muffler.

crios · 03-06-2009, 03:41 PM

LOL, I guess I better start writing that speech for this year's Porsche Parade in Colorado. :dance:

Thanks guys! Just keep mod'ing and sharing!!!

TimAustinW · 03-17-2009, 10:59 AM

Are you running OEM Headers and Midpipes with all cats intact? Just curious.

I just got a new OEM S muffler on Ebay so I may try this with my current muffler to see how it sounds with my performance headers and secondary bypass pipes. Might get too loud.

MN 986 · 05-26-2009, 08:26 AM

I did the crios mod on my 02 2.7 about 2 weeks ago, and am loving the additional sound at idle, and cruising at 2500 to 3000 RPM. That is where I notice it the most, but I am sure it adds a little sound all the way to redline (de-snorkled intake noise drowns it out).

I'd love to drill another hole in each side but with the welded on tip, 1 hole/side was hard enough. Maybe I can find a bigger bit and make them larger.

Thanks for the idea, crios!

GT_YellowJacket · 06-22-2009, 10:38 PM

First off, a bump for this awesome mod!

And in almost every exhaust/intake mod discussion, I hear at least one person say "I wish I could hear them side-by-side!" Well, today I got my chance! A fellow identical 2003 Boxster S owner brought hers to my office and we parked them side by side for a little comparison.

I've got mine drilled with one hole per side with only a 3/8" bit and little bit of extra filing to ovalize the hole. Hers is completely stock. Definite improvement in low RPM sound in mine. Even with the relatively small drilled holes, it has a much lower, aggressive growl. Improved sound continues until the de-snorkeled intake sound takes over on mine.

I didn't realize how much of an improvement this minor mod actually made until I could hear them side-by-side! It doesn't take a lot of drilling to make an impact either. Well worth the 10 minutes!

And for grins, a picture of our test lab...
987
986
986

tamarsha · 04-01-2009, 01:13 PM

I tried the mod with a 1/2" bit. The largest I have. It did make a little bit of an improvement. Impressed for 2 mins worth of work.

What do you think would work better. Expanding the hole with a larger bit or maybe drilling another couple more holes in the pipe? Or would both accomplish the same task?

crios · 04-01-2009, 04:08 PM

I'm glad you like!!!!

Add a second 1/2 to each side to make louder.....here's a thread on this:

http://www.ppbb.com/boards/ppbbphp/showflat.php?Cat=&Board=ARCHIVES&Number=1487599

Sound clip:
http://www.tripdevice.com/bryan_temp/ppbb/cse_exhaust_hack/cse_exhaust_hack_long_4holes.mp3

2000PorscheBoxster · 06-24-2009, 11:52 AM

Can someone please confirm this mod also applies to 2000 porsche boxsters (NON-s)?

I was sizing things up and it seems drilling straight back as far as possible much punch through the exhaust all together (i measured it and compared it on the outside and it almost seems the back wall is the exhaust shell wall!!!)

in other words, can someoen please confirm on a 2000 boxster NON-s model, i can just take an extra long drill bit and drill all the way as far back as possible?!

THANKS

2000PorscheBoxster · 06-24-2009, 06:53 PM

okay okay, i drilled THREE HOLES per side and it seems i've gotten nowhere1

as stated previosu, i have a NON-S 2000 porsche boxster

It seems i have drilled three holes per side into an isolated chamber thus producing zero net results!

Should i keep drilling and pierce the wall of this chamber and finally find a chamber that will produce some symphonic exhaust sounds?

nola911 · 04-02-2011, 06:06 PM

Nice work guys.

Just did the "ghetto mod" on my boxster. I might need to go much bigger and maybe more holes, mine didn't make any more noise with a 5/8" bit except MAYBE at idle- but that might be in my head..

Ill post back. Love the idea!

davey · 10-18-2010, 02:09 AM

On the early welded single exit boxes could you not just drill one big hole between the two outlets with a tank cutter? It would have exactly the same affect.

tamarsha · 10-18-2010, 02:22 AM

Quote:

Originally Posted by davey

On the early welded single exit boxes could you not just drill one big hole between the two outlets with a tank cutter? It would have exactly the same affect.

Sounds logical to me. The whole point is to tap into that center chamber.