Anyone have any experience with something I saw extensively written up and even dynoed on the 6speed site;

They are going in through each outlet pipe and drilling/grinding 1" and up to 2" diameter holes in what is apparently the muffler inlet tubes that cross in front of each outlet........effectively creating a partial muffler bypass.

They appparently are producing some power gains (back to back dyno runs) but my real interest is in a better sound - without power loss.

Lots of folks have done it and found the sound to be decent....especially for the price.

I had a 993TT that had straight pipe bypasses on the two mufflers after the cats and found it to sound stupid, so I'm not sure I want to risk a muffler.....although their are lots and lots of takeoffs for cheap floating around if I didn't like the results.

Thanks for any help or input.
MK19

 

Actually, I was the one that "invented" this mod.
I had planned on getting an EP2 at some point but couldn't stand how quiet the car was for another moment. I figured if it didn't work out I'd just get the EP a little sooner than I expected.

The sound is a lot better than stock but not too loud at all. sounds as good as some aftermarket exhausts I've heard.

One of the sixspeed guys did a before and after dyno on it and the gains were pretty good. I was hoping for at least no losses so this was great news.

The mod is not meant to be for gains, only to get a little better sound.

The cars are now worth 60 grand instead of 130k so it gets harder to justify 5K for an exhaust.

You can DIY or have a shop do it for around 200.00

tw

 

I started with a small hole, about 1" diameter and round. The sound was a bit louder than stock in normal driving, and the pitch was quite deep. At WOT there was a lot of hiss/whistle. It sounded much like the compressed air blow-off gun I have in the shop.

Then I elongated the holes to be about 1-1/2" tall by 2" wide. Most of the elangation was towards the rear of the car, so essentially "hiding" behind the baffle that turns the flow toward the center of the car after the 2nd cat. I did this with the hope of minimizing whistle.

I think it worked. The sound is one step louder everywhere, and doesn't whistle at WOT. Take the following sound assessment with a grain of salt, because I don't really like the sound of boxer 6s. It's better than the "Beetle on steroids" sound of a hot rodded Subie, but not pleasant to my ear. So... the free exhaust mod (I already had all the tools) sounds better than stock (if you like a bit of deep exhaust sound), no worse than any of the aftermarket systems I've heard, but not as nice as the EP2L (based on the sound clips I've played). The EP2L sounds "smoother" and has a higher pitch than any of the others I've heard.

Jeff

 

Thanks guys.....I appreciate it and will post my thoughts after I take the plunge....if I indeed do it.
MK19

 

I followed tdub. His idea. He was laughed at....it worked. I am of the same name on 6speed and put some videos up. I like the new sound better. Best of luck.

Thank tdub!
JB

 

Thanks jcb! and all.