DIY Exhaust Mod – Gain of 10+ HP!!!

[sd_boxster]

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]

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]

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]

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]

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?

[spine911]

Just wondering if there are any HP, Torque gains, or losses from this mod....Keep in mind the internal bafflings are there NOT just for sound but to promote efficient backpressure for optimum HP gains...Probably ask Mr. Raby to do some study on this mod.

[23109VC]

i'd be suprised if two little holes make a whopping difference in back pressure - sufficient to lose power. i think the little holes just let enough extra sound out to make it "noticeable"....

but what do I know... I'd love to hear from an "expert" if any of these "DIY" exhaust mods add or lose power - my guess is that they do nothing detectible except make nice sound.

[23109VC]

Originally Posted by clb0099

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?

clb0099-

i am in the same boat as you - I have a welded on muffler. on the cars with the welded on oval tip - if you look *WAY* deep inside the tip - you can see that there are actually TWO separate tubes that essentially join together at the tip - if you look at the picture that crios posted - of the muffler which is opened up /cutaway - you see two distinct internal tubes - and at the exit where they turn into tip s- there is at least an inch or two of space between them - hence he drilled toward the center of the tips - but on OUR Mufflers, there is NO space in beteween those tips.

if you drill "inward" like he did you just drill into the other tube...and it won't work.

i am tempted to drill the opposite direction - OR just drill straight back. i can actually see the "bend" in the back of my tip.... if you shine a flashlight straight back, you can see the tube bend toward the outer portions of themuffler... much in the same way that the cutaway picture shows...it's just that they start much closer together..so you can't drill inward...you need to either drill upward, outward, or just drill in the very back and punch through that way.

i have a very very long drill bit - almost 12" long and it easily reaches that back portion.

i'm very tempted to just start drilling right now.

[sd_boxster]

Do it! That's what I did.

Installed headers today. Wow - it is MUCH louder. Wonder how the wife is going to feel about this.