+1, in fact, you can penetrate the back with the circular bit alone if you are not careful, like I did

This sounds like a great hack. Reminds me of the De-Snorkel hack for Boxsters.

Does anyone of have "before" and "after" videos and sound recordings?

If anyone is doing this in the near future, please make such a video/recording with a digital camera in movie mode. Suggestion:

A) Before you do the mod:

1) have a friend video the tach as you take it SLOWLY up the rpm range to redline in 1s and 2nd gear. Once you reach redline in 2nd gear, let go of the gas and let the rpms fall naturally down to idle while keeping the car in 2nd. Do this on a smooth road and windows up to minimize tire noise.

2) do (1) with the windows down

3) get a friend to video from the outside as you accelerate away at a normal pace

4) video from the outside as you accelerate away but hard

B) Repeat 1 to 4 after the mod.

The reason I ask is because I read through the entire thread and was very interested. There is a similar ratio of people who loved the effect versus those who didn't as there was for the Boxster de-snork hack (i.e. nearly everyone loved it, just a very few dissenters). However, unlike the Boxster hack, this is not reversible. So I'd like to hear it first.

By the way, I'd do the videos myself but my TT hasn't arrived yet (it's on its way; maybe 2 weeks?)

PS: first post!

Here are some track fly-bys with the the mod:

http://www.youtube.com/watch?v=ommBEX6RFY8

http://www.youtube.com/watch?v=Pl8WdVsaOjw

Wow guys. From the J of the TJW mod, thanks for all of the posts. Truly a fun, DIY mod.

Jeff

WOW 320 posts and still going.

OK I got my 01 TT and want to improve the exhaust note without jumping on a 3K aftermarket and this mod sounds like it might fit the bill.

As far as tools to use for drilling the holes, I saw reference to Unibit but they dont seem to go beyond 1 3/8". Have most folks who went 1 1/2" to 2" used a hole saw with a pilot hole? Did anyone have trouble with the plug falling inward when drilled? It seems that the pilot bit would need to come out to keep from drilling through the back side.

I did see a reference for using a PVC pipe as a guide for a hole saw which sounded interesting.

Thanks for the insights.

Keith

Smith3933, check this out see if it helps.

https://www.6speedonline.com/forums/...-delete-2.html

Keith,

I had similar concerns using the hole saw, but you'll see that since it is on an angle and the saw actually removes a good amount of the diameter of the hole, the remaining oval gets caught inside the hole saw pretty easily. I would imagine it is still possible to lose it inside the muffler, but if you are careful, no worries here.

I did not use the pilot drill hole or the PVC pipe. My only issue was drilling too far on the first one.

Personally, I love this mod, just makes the car loud enough to hear it when you get on the gas.

--BM

i did this modification last week and had so much trouble drilling on the drivers side. the hole saw is not biting even with the pilot drill. i never had a problem doing it in the passenger side but slit the back of the exhaust a little bit. up to now i cant seem to get it to bite and lost the drill bit inside the exhaust and can't get it out. ahhh! i dont know maybe i'll just take it to the shop and have it done there or maybe a new exhaust...any advice?

Get a strong magnet and pull it out w/ that. Tie a string to it and push it in then gently pull it out. What size hole were you trying to drill? You have to take it to a shop to get the slit welded unless you can do it, they will be able to get your bit out.
Oh, is it in the pipe or the cavity the pipe snakes through?

You have got to be kidding me, I haven't drilled holes in a muffler since high school. Man up and buy an aftermarket exhaust or take your OEM to a professional to modify. Sorry for the rant...

I bet you get told your #1 a lot.

i tried the magnet pushing it about more than a feet inside but no luck in getting it out. i used a rubber mallet to hammer under the exhaust to find out if the bit is vibrating or moving so i can find where exactly its place but ican't here anything. my hole saw is 2" in diameter by the way.
why is the drivers side/left exhaust is harder to drill a hole? it only took me 5 mins on the right side. i tried starting it and the sound is great just have to find a way to do it on the other side. i'm just waiting for a nice weather, i'm in chitown area and weather here right now is unpredictable.

i'm really in the market for a new exhaust and i've modified a few car in the past and never had this kind of mod. i was following this thread and got curious especially with the back up research on hp gain and sound inmprovement plus the fact that a lot of 6speeders have done it and recommending it. so i took a chance and did it. my skill is about 4/10 when it comes to diy but just messed up with this one.

Ibmw, harbor freight has a tool that is about 2 1/2 feet long and is like a plumbers snake. It can bend and curve around to get into tight spots. At 1 end is a red button, the other end has a 3 fingured claw that comes out when the button is pushed then retracts when the button is released. It's handy for picking things up in places like this.
I'd take the complete muffler off to give me the ability to move it around and try to dislodge the bit that way. Plus you might find this helps in drilling out the other side. You can also drill out some of your cats.

looks like i'm gonna have to drop the exhaust...thanks for the advice/suggestions