I did the Pedro exhaust to my car - by buying a muffler that already had it done.

I had a pretty bad exhaust leak that was just fixed today - so in the next day or two I'll shoot some video of my car and post it to see what you all think. just before putting the pedro muffler on - I did the crios mod by drilling two 1/2" holes. I think the pedro muffler is a bit louder and it has a different sound. both were good. I would have to hear them side by side to say which I like better...

I think I might like the $2000 fabspeed system more... but my wife won't let me spend that much!! :)

seriously - I think both mods are good - i'll post my clips later and you can all be the judge.

one thing I notice is that at higher rpms/speeds - I think I hear the intake more than the exhaust. i'll bet an evo intake would sound awesome.

I was just about to do the Pedro mod but my exhaust man and I started to get nervous about how close the pipe would have to be to the bumper. I had just deiced to save my coins for an aftermarket exhaust when I saw this mod.

Has anyone ever tried to bypass the secondary cats with… oh… say a piece of rebar or some ridged conduit? I have heard people talk beating the hell out of cats to break them up and create more flow. I wonder how hard it would be to ream out the secondary cat.

Any difference in doing this mod to a S model? I'm contemplating doing this but haven't seen if anyone is doing this to an S.

crios, the links aren't working.

Also has anyone tried this on the Boxster exhaust with the non-removable tip? I have a '98 Boxster and would like to try this mod but I don't know if I can get the right angle because the exhaust tip is welded on.

Just as easy, Voxster from the PPBB site did it to his 03 S, sound clip and pics below.

He actually did two holes in each tube, so 4 all together.

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

http://www.tripdevice.com/bryan_temp...h/IMG_4258.jpg
http://www.tripdevice.com/bryan_temp...k/IMG_4734.JPG
http://www.tripdevice.com/bryan_temp..._part_deux.jpg

All links have been update and should be working now.

As for doing on a 98....try a long drill bit and go straight back into the bend?

I did the 4-hole mod on my '03 S. Worked out great. If you have an '03 or '04 with the removable tips, there is no reason why you should do this mod now! It is free, it sounds good, it is free, it is easy, did I mention that it is free.

It didn't make a huge difference in sound, but it does sound better. It is a little louder and has a more grumble to it. It is not at all over powering, resonating, or annoying.

Drill Baby Drill!!!!!!!
 

Crios.........U R DA MAN!!!!! Just did the Mod on my 2000 S and I love the sound.


For all of you that have the welded on tips, don't let it stop you.

I just got the longest 1/2" bit Sears had it stock and bored straightback through the pipe. I put the second hole about 1 1/2" from the first one. The placing is not too critical but you should allow enough room between the two holes to prevent compromising the structural rigidity of the pipe. If anyone is considering this Mod, I would definately go for it. It does help to put penetrating oil on the drill dit. This helps the bit cut through the metal smoother. Also, don't forget to put some duct tape around the outside edge of your tips to prevent them being scratched by the side of the drill bit. Good luck and............. Drill Baby Drill!!!!!!!!!!

Calling all the brave among you........
 

............who will be the first to go 3 or 4 holes in each pipe? Larger holes? .......... :D The sound is good now but could it be better?

Just drilled the mother - Boxster 2003 2.7 tip
 

Hi guys, first post on 986, I have been following this thread with an open mind and decided to go ahead after all the good reviews. Went & bought a 14mm by 250mm all purpose drill bit as my oval pipe is spot welded on. Pushed the drill bit as far back as it would go and let rip. When I shine a light down the pipe you can see the hole at the back but you can also see more metal directly behind the hole, it's even scored by the drill bit & I'm sure I would of gone through this if I'd carried on pushing. Does anyone know what this will be and should I drill through this as well? The sound is better and I'll be taking it out later to test drive. Cheers

How To Question
 

A tad embarrassing but I'm missing something so simple I can't see it. Went out to drill a couple of holes inside the exhaust tips into the muffler chamber per the example in the earlier post.
No deal: the angle of the drill wouldn't let the bit bite, it just keeps wanting to move around, attempted to use smaller bit with the idea of working up to the 1/2" but no luck.
How did you do it?

Thanks

Hi, I had the same problem, I started with a standard cordless drill & the bit just spun all over the inside of the pipe. I got a bigger mains powered drill, put all my weight behind it & pushed like f**k! This is why I had to go more to the back of the pipe as there is no way I could have put a hole where crioas did with the tail pipe on, couldn't get the angle. Does anyone know what is directly behind the hole I've made as per my previous post?

You will want to use a center punch to place a "dent" where you want the drill to go through the wall. Any hardware store has them.

Center punch as suggested by blue2000s, or/and you'll have to push in and to an angle, agaist the wall to use as leverage, leaving some cuts on the pipe. You can also cover up the drill with ducktape where it hits the wall to help prevent these cuts. Go slow, into you establish a groove where the drill will stay in place.

See pic below:

http://lh6.ggpht.com/_9sTq_sN1KDw/Se...x_2009_004.jpg

No Takers?
 

Don't be a :chicken:! Still interested to hear if anyone is enough of a rebel to drill more than 2 holes per side.

Lov'n the Crios! :dance:

I'd bet that you are seeing the outer shell of the muffler. DO NOT drill through that.

I'll be borrowing one of my Dad's long drill bits early next week.

BTW, I would guess that you are only hearing the difference in sound at low RPM because at higher RPM, the volume and velocity of the air keeps it moving through the big holes in the existing pipes as opposed to the tiny drilled holes. At slower speed, there is less air moving, and it can get through the smaller holes.

I'll put a DB meter on it before and after to see what difference in sound level it makes.

i have a pedro mod on my car and I notice one sound from the muffler at lower rpm and then a totally different sound at higher rpm.

i wonder if the pedro mufflers could also have an issue where at certain rpms, the amount of air that actually makes it into the bypass pipes changes? i notice the sound of my pedro muffler is different at low rpm vs higher rpm - which could be the result of air flow/velocity allowing more air to get into the bypass pipes, but at high rpm less can make it due to more of it flowing out the "real" muffler piping and less can divert/escape into the bypass pipes??

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). :cool:
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! :cheers:

Side-by-side comparison
 

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

http://photos-f.ak.fbcdn.net/hphotos..._2426169_n.jpg

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

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?

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

PICTURES

what's going on here? where's the noise?

http://i230.photobucket.com/albums/e...d/CIMG7075.jpg
http://i230.photobucket.com/albums/e...d/CIMG7078.jpg
http://i230.photobucket.com/albums/e...d/CIMG7079.jpg


http://i230.photobucket.com/albums/e...d/CIMG7080.jpg

nobody can chime in on this one?

Although the holes that you have drilled are slightly smaller than the two that I drilled they are in a similar position to my own,you should be hearing some increase in noise by now! :confused:

Emmissions issue?
 

Sorry to be a downer....but would drilling the exhaust cause the car to fail emissions?

The addition of holes in the muffler tubing can't effect emissions. It will effect noise level.

And some states do have distinct noise level limits, CA for one comes to mind, so it can enter into the picture at inspection time..........

I was thinking about this too but i would like to ask about improving the flow even more. What if you cut a piece of pipe out at the Red arrow section? Or even at the Teal arrow section and have the exhaust just escape freely from there? Would the sound be too loud for street use?


http://i744.photobucket.com/albums/x...r_cutaway2.jpg

This is what i'm talking about. If you cut the yellow parts out with a power saw or if u can get the muffler off you could probably use a hacksaw. The exhaust would go in and fill 1 chamber and get right out of your exhaust tip bypassing all the chambers. You could also probably fashion a straight pipe from that entrance to the exit. I think you would also have to block off the teal side of the muffler with something maybe weld a piece of metal, or some kind of metal clamp with a cap. I guess it wouldn't hurt your exhaust system if you left it open too because it would just recirculate to the first chamber.

if christain H is right below and i have drilled as prescribed in this thread... then i must report i have noted no appreciable sound difference!!!

unless the 2000 porsche boxster base model mufflers were designed differently, i will probably have to try the PEDRO PENNY MOD instead for serious sound improvement...

oh well.

I just smog’d my car in CA last month, passed.

The sound is not LOUD, it's simply deeper. It's a growl, not a bark.

As for visual inspections, they check if you have done anything to the filter area, not the tail.

You cannot even see anything in my pipes, they are so dark with oil!

Most of the conversations I’ve had with CA residents having problems with the noise issue resulted from them getting noise tickets which required them to got to a smog check station to have the car “certified” before going to court. From what I have been told, if you get one of these summonses, testing is required according to the CA specs, which use a sound meter behind the vehicle a specified distance and on an angle to the side. The car is then revved to prescribed RPM levels while in neutral and the sound level is measured in dB. Usually, once you pass the test, the ticket is dropped.

I know you guys have some draconian laws about modifying cars, so I’m not at all surprised they check sound levels.

Listen to the sound clips again.

The car is not loud that it’s annoying to people and would get them to turn their heads. It just sounds like an aftermarket exhaust, but about $2K less.


http://www.youtube.com/watch?v=RfRErzkyqNc

Crios Mod
 

Fellow drillers....I have just completed this mod on my 99 no removable tip...Purchased long 1/2 bit from sears...drilled just left of straight Back....both sides...nice result I was hesitant...glad I went ahead...in my opinion:
Below 3000 rpm is noticable...idle and just off when acellerating sounds best lower and somewhat louder no unwanted rasp or drone....above 3k rpm induction with de-snork is more prevelant and SWEET by the way!...overall would recommend.

Tom D.

Congrats!

10

Thanks...appreciate the comraderie? :cheers:

Great idea
 

I have been thinking of doing this to my 2003 tip since I first read about it. Now I just need to decide if I should start with 1 or 2 holes per side. :) :)

Since it's a dual pipe, you need one in each side, so two holes :cheers:

I though that I read an entry saying someone had drilled 2 holes per side? :)