Muffler Modification
 

I believe I read this somewhere herein but I haven't been able to find it to follow up.

I drilled out my muffler this weekend and it made an obvious improvement. The tone at idle is deeper and "throatier". The volume on the road doesn't really change as it is not loud enough to hear. It feels quicker to respond and much nicer. I recommend it to anyone who wants a cheap (tools less than 100 dollars) exhaust mod with noticeable improvement. No negative noises. I drilled two 2 1/8" holes with a step-bit and it lets the muffler "breathe" better.

I read on another forum that the muffler "drill out" mod had been done. On the forum I participate in for 911's they had a car dyno'ed before and after showing between 25 and 35 RWH gain depending on the RPM.

http://i273.photobucket.com/albums/j...n/DSCF5301.jpg

Is this the mod where you have to drill through the baffles?

in boxster land it's known as the 'crios mod' and lots of info if you google. the only way you're going to get 35 hp out of it is if you add an electric supercharger, however.

On the forum I participate in for 911's they had a car dyno'ed before and after showing between 25 and 35 RWH gain depending on the RPM.



All the exhaust modifications in the world won't create 25 to 35 horsepower gain at the wheels for either a boxster or 911 . Let alone simply drilling out the muffler .

And if your Boxster has the welded on tail pipes, you won't be able to use a strait drill bit to drill out the pipes anyway - there isn't enough room.

That looks like one LONG drill bit. How is this done. Any cut away views that we can all understand a little more?? Bueler, Bueler!

Here's the thread describing the modification.

http://986forum.com/forums/diy-project-guides/19770-diy-exhaust-mod-%96-gain-10-hp.html

Easily done with a 10" extension and a step bit. The initial "dimple" was done with a punch done on the curve to allow the step bit to bite. Once that happens it's straight through. Done on the curve pretty easily.

The 25-35 RWH was achieved on TT 911's. On the NA Boxster's it allows the exhaust to flow much freer. Great sound, if nothing else. A little release on the out-flow never hurts.