DIY Exhaust Mod – Gain of 10+ HP!!!

[tuneme]

Do you guys think you could do this with removed cat's?? its a 03 non-s with a remapp and intake and both cats removed... please let me know

[tamarsha]

I have an 03 S with a BNC filter, secondary cats removed, 200 cell primary cats, and FVD software and I love still love my exhaust mod. Go far it! It is a cheap (free) easy mod.

[tuneme]

Ok got a drill and did it, but i only drilled one hole as its already noisey without cats..
and all i can say is WOW sounds close to a GT3, incredible gonna take it for a drive and see how she go's otherwise i recommend this mod highly!!!

ps. il try take a video

[tuneme]

im even considering drilling a 2nd hole, but im scared about back pressure problems
iv booked the car for dyno, so ill see whats what hopefully there some gains

[dja1980]

Oooh... definitely let us know the results of the dyno!

[Seal Gray S]

I know this is a dead thread, but there were some questions about making this mod to a S muffler with welded tips and avoiding drill bits from walking due to the drill bit attack angle. Here is what I did. 1) using a long flat screwdriver and hammer, chisel the screwdriver’s tip into the pipe where Crios recommended you make the holes. 2) When the edge of the screwdriver just starts to dig into the pipe, angle the screwdriver so the tip will travel upward making a 1/16th in cut. 3) now put the tip of the screwdriver near the origin of the hole and angle the tip down so you start making a "v" in the pipe as you advance the tip...continue doing steps 2 and 3 making the "v" big enough so you can get a 3/16th inch drill bit on the flat surface that the "v" makes. 4) using a 3/16th inch metal cutting bit, drill a hole through the "v”. 5) continue to increase the hole size by steeping up the size of the bit.
I struggled with a solution for the bit walking for about 2 hours...tried using the wood block method with no luck...came back to read this string about 3 times...then got the balls to start using force. Once I figured it out it took me about 20 min to finish the job.

Good luck.

[Renorush]

I know this is an older thread, but I have a question. The original pics supplied by crios on 3/2/2009 show a muffler opened up showing the chambers inside. If a hole is drilled into the exhaust pipies coming out the back into the center chamber, it doesn't look like it would connect to where the exhaust gases would be coming out. The two pipes that come out the back appear to go to the left and right and the exhaust gets to them from the chambers to each side, not in the middle. So unless I'm missing something, drilling the holes as shown would only go into the middle section which has not exhaust gas connections with the other chambers. Is this correct?

[fredpayne]

This looked like a great MOD, I got my first hole drilled in the right side, then went to drill the hole in the left side, no problem drilling, THEN, oops, my bit came loose and is now inside the muffler, called stuff happens. : -) or should be : -(

[Eric G]

OK, after reading all the posts I decided to try the mod out and figured the worst I would be out is a stock muffler that I would have to repair. On the 98's they appear to have a harder curve then the one at the front end of this thread. Realized that I was not going to get a starter bit in make a hole. Used a large regular screw driver and with one hard tap of a rubber mallet I was able to make the starter hole. I ended up going with a 1" bit in the end.

One word...WOW! My 0-60 time on the car is shorter by about a second...the sound is wonderful starting a about 2800 I get this beautiful feedback that sounds like a GT. Top down it is sweet, top up not one bit of an issue. If you are worried, don't be...this is both a cost saving mod and very easy to do.

[JAAY]

You lost a second because of a drill bit! Man Porsche engineers are dumb. :dance::dance::dance::dance:

0-60db is probably 1sec quicker but thats about it.

[Eric G]

Your post makes me laugh! This was run with diagnostics on board more then just seat of the pants calculations. Make fun if you will, but simple physics don't lie, when you allow an normally aspirated engine breath easier (to a point) you will see improvement.

The difference between the energy content of the fuel consumed and the useful power extracted from the engine is known as Thermal Efficiency (TE), this is just one factor that aides in the increase of this.

While Porsche develops "performance" factors into their cars, those factors are also dictated by standards of operation as a commercial vehicle that must meet country standards where sold. Performance is not always at the forefront of those factors. The stock muffler and exhaust systems are not designed for maximum performance...if they were, you would see them run on on the track.

What we do to the cars is all about what you are looking for and what you can extract from them to get to that point. This mod is just one of those, you can either think outside the box, stay with stock or buy someones idea...but in the end it is what make you the owner the happiest. For me, I am very happy with the end results.

[gilmanco]

Why ghetto up your car just spend money on a real exhaust with proven HP gain?

[fredpayne]

Originally Posted by gilmanco

Why ghetto up your car just spend money on a real exhaust with proven HP gain?

I did, after I lost my drill bit in the muffler, I bought a set of Borlas

[MN 986]

Originally Posted by fredpayne

I did, after I lost my drill bit in the muffler, I bought a set of Borlas

I know how you feel. I almost lost my step drill bit also, so I would recommend caution when drilling (maybe don't have the drill go all the way in to the muffler/stop short of the last step).
I did this mod a few years ago and thought it was worth doing for a little more sound, mostly at idle. The added sound may have been a contributing factor in me wanting even more sound, and I eventually bought a FVD 'sound version' muffler and this year I am adding 'Che' secondary bypass pipes.
Think of the crios mod as a 'gateway' exhaust mod!

[fredpayne]

Originally Posted by MN 986

I know how you feel. I almost lost my step drill bit also, so I would recommend caution when drilling (maybe don't have the drill go all the way in to the muffler/stop short of the last step).
I did this mod a few years ago and thought it was worth doing for a little more sound, mostly at idle. The added sound may have been a contributing factor in me wanting even more sound, and I eventually bought a FVD 'sound version' muffler and this year I am adding 'Che' secondary bypass pipes.
Think of the crios mod as a 'gateway' exhaust mod!

I just wish I could get my drill bit our of the muffler, then I could sell them to a friend of mine, any ideas on how to do that?

[Crono0001]

Well, after driving around like this for a few weeks, I must say:

Wow, the sound is incredibly noticeable. Especially when you're driving down the street. It's a world of difference. Not too much of that loud ricer gurgle, but just enough of that throaty dark growl.

And no, I don't feel like the car has gotten any slower.

[Crono0001]

Sorry for reviving this up, but I have a post that might help people.

I recorded my car revving it up before any DIY mods. Link here:
Pre Drill and De-Snork DIY mod for Porsche 986 - YouTube

Today I went ahead and tried drilling my exhaust. Because I didn't have a long enough drill bit, I could only mar the surface and create a small hole. No biggie, I took a file and hammered it in, and was going to file a gigantic hole... But after an hour of filing, I only got the hole to be 1 cm -_- Bigger holes to come.

I went into the car, turned on the engine, started revving up... No noticeable sound difference.

I also did the de-snork mod afterwards since I wasn't happy with the sound increase (or lack there-of). Pulled the grill apart, ripped out the snork.

I went into the car, turned on the engine, started revving up again... No noticeable sound difference.


HOWEVER, I did record an after video, link here:
Post Drill and De-Snork DIY mod for Porsche 986 - YouTube

And if you compare the two videos, there's a VERY noticeable sound difference. The second one is also growler and throatier. You'll also notice the idle growl that wasn't there before.

Moral of the story: DIY Drill and De-Snork mods won't make a huge sound difference... but it does. Watch videos and judge.

[MethosSVT]

Hi everyone, I have a few questions and I'm sorry if it is an old post but I wanted to know if anyone has dynoed or felt a torque loss in lower rmps? According to the cut-out muffler in the picture, the middle chamber doesn't comes in contact with the exhaust gasses right? It's hard to see but it seems to be a neutral chamber that has nothing to do with exahust flow, and if that's the case I don't think there should be any power loss, but then again there can be exhaust gas turbulence when the gas from the chamber and the pipe meet, creating thus more restriction. I'm just guessing here and probably that far out in the exhaust turbulence wouldn't be a problem, let me know if anyone has more info on this, have a great day everyone

[Michiganstar]

3yr old thread resurrection!!

I have just completed this mod on my '03 S and I'm really pleased with the results. The facelift exhaust/combo mean that you have to go in at quite an angle but its still easy enough. I had difficulty getting started with the large drill bit so I went with a smaller one to get the hole in place then went up a few sizes and on the 2nd drill and finally went with the large drill bit and it went through first time.
Really pleased with the throatier sound at idle and also there is a noticeable woofle at around 2800rpm. This is all achieved with no drone at highway speeds. Well worthwhile mod to do IMO.

[Homeboy981]

Cat Back System is a better responding and sounding way to go!

IF you have to do it, and when I was a newer member I did, use a metal punch from Lowes for shipping cement. I found a 1" version and made the holes within a few minutes. No stuck drill bits. For a couple hundred bucks you can chunk the "boat anchor" and get a really cool sounding exhaust…instead of a faint glimmer of one!

Anyone want a boat anchor with a Crios mod?