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

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!!!

23109VC · 03-08-2009, 11:59 AM

last night i had a chance to listen to sd_boxster's car in person.

I took some quick videos of the sound and when time permits I'lll try to upload them. I have to say the sound was pretty good. I would descibe the actual sound as being almost the same as stock in the WAY it sounds, just louder.

I've heard online/youtube clips of aftermarket exhausts, and some of the pedro systems and the sound of the car is "different". some of the pedro exhausts have what I would categorize as a "raspy" sound at higher rpm.

sd_boxsters car did not sound raspy at all. I got a chance to take a quick spin in his car, both with the top up and down. I never heard ANY resonance. When the top was up, I honestly had a hard time telling that the exhaust was ANY louder than stock while we were just cruising.

if you are outside of the car while the throttle is blipped, or the top is down and the car revved up toward redline, ,then there was a noticeably increase in the sound - but again, I'd say it was similar in overall sound to stock, just maybe 20% louder.

i like this because I honestly like how the boxster sounds, I just think it would be great if it was a bit louder.

I could tell it was louder and sounded better but it was NOT objectionable. You will not get dirty looks from the neighbors, and this would easily pass the all important "wife" test. I am almost certain my wife would not complain about this exhaust - which many of you will understand / appreciate.

I am now VERY tempted to try this on my car. I was staring up my exhasut pipe wondering how long of a drill bit I am going to need...as I have the older style welded on tip - it won't be quite as easy, but I still thinkI can do it. I can see the exhaust pipes inside there, I just need to figure out how far/how long of a drill bit I'd need and exactly what angle.

does anyone know if there is any difference internall between a 2000 muffler and the 2003 mufflers that are on crios' and sd_boxster's cars???

clb0099 · 03-08-2009, 12:37 PM

I am in the same problem as it would be a different angle to drill the muffler since i have the welded tips even with the extra long drill bit.. i have a little torch do you think it would be easier to just remove the tip and the re-weld it. and could i just screw the tip back on instead of welding it back?

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?

2000PorscheBoxster · 06-26-2009, 09:42 AM

bueller buelller bueller!

can someone chime in on this?

or a cutaway of the 2000 OEM porsche boxster non-s exhaust would be helpful too (i could determine whether to keep drilling through or not)

Christian H · 06-26-2009, 11:39 AM

Quote:

Originally Posted by 2000PorscheBoxster

bueller buelller bueller!

can someone chime in on this?

or a cutaway of the 2000 OEM porsche boxster non-s exhaust would be helpful too (i could determine whether to keep drilling through or not)

Hi Fella!

Sorry your having trouble doing this mod,

I have a 1999 986 with the single tail pipe like yours, I had a bit of trouble making the inital holes, but even with small diameter 10mm holes the sound was noticable louder, when looking into the end of my tail-pipe the holes are just before the bend towards the middle, not sure why you have not had any results yet.
Could you maybe post some pics that may help others to diagnose your problem

Chris

EZ2CY · 01-27-2015, 07:14 PM

Quote:

Originally Posted by 2000PorscheBoxster

bueller buelller bueller!

can someone chime in on this?

or a cutaway of the 2000 OEM porsche boxster non-s exhaust would be helpful too (i could determine whether to keep drilling through or not)

OK champ.. sorry to get here this late in the game of frustration. i have a non- S 1999. in the case of my muffler, the reason you were NOT getting a difference in sound is because the CHAMBER is already OPEN to the front and outside, right between the 2 exhausting pipes....so you are not making a difference by drilling again, UNLESS the drilling was significantly larger than suggested by CRIOS...(my new hero BTW). Don't have pics, again, at least in my case, that is what i found. the CENTER chamber is NOT sealed as in the case of the pics shown by CRIOS.

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!