# OEM muffler cut open(modded)



## Jurpo (Jun 24, 2009)

Design of it is not bad at all. I say superior to some aftermarket systems.
Makes one wonder,what will sound be like if holes were drilled thru casing.
Into end pipes.








More here.http://forums.vwvortex.com/zerothread?id=4187844


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## Jurpo (Jun 24, 2009)

Yes. It does sound better with holes drilled.


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## cwiseh_tt (Feb 19, 2008)

holes drilled where?


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## Jurpo (Jun 24, 2009)

These pipes marked X. That makes an bypass.








Underside pic. Holes plugged with 5x20mm ss washers x4,ss pop rivets x2








Black dot is better location for right side hole. 10,5mm holes on both sides of pipe. Now 10,5mm,12,5mm


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## Dance171 (Feb 8, 2009)

Does this not lose performance with holes being cut in?


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## les (Jul 24, 2006)

Dance171 said:


> Does this not lose performance with holes being cut in?


 and fail the MOT due to exhaust blowing through holes? :?


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## Jurpo (Jun 24, 2009)

Increased rerstriction is not likely. Reduction maybe.


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## Jurpo (Jun 24, 2009)

les said:


> Dance171 said:
> 
> 
> > Does this not lose performance with holes being cut in?
> ...


External holes are plugged up.


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## dzTT (Mar 11, 2009)

the police will try to get u done for excessive exhaust noise however :wink: friend done similar mod to his civic with same sort of noise output range and he got a 50quid fine and had to remove it and get garage stamp to say it was removed and swapped etc.


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## Jurpo (Jun 24, 2009)

It is not that loud. Golf V R32 is louder. Stock resonator is still there and rear silencer is not completely out of picture.

I did try smaller holes. It did not make enough difference.
Passed MOT not a word from inspector.
I dont like overly loud exhaust sound. (at one time i had tuned Beetle with stinger muffler.Man that was LOUD  )

Sound level can be adjusted. Bigger holes louder and so on.
If it is not obvious :? There is no need to cut silencer open. Standard size drillbit is long enough.
Can be drilled on bottom or exhaust removed on top side.


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## dzTT (Mar 11, 2009)

fair enough. nice work anyway mate. was it easy enough to do?


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## Guest (Nov 24, 2009)

hmmmm. i'd love a bit more sound from mine, bit scared to drill it though i think


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## Jurpo (Jun 24, 2009)

Yes easy to do.  
Sound vid link:
http://s818.photobucket.com/albums/zz104/lerppa_photo/?action=view&current=2009-11-23-73893.flv


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## rapid225 (May 30, 2009)

^^ Awesome video!

Yout dont have no other modifications? Like induction wise?

Sounds alot alot louder just for 2 holes to be drilled!


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## Jurpo (Jun 24, 2009)

Oem Air box. Tyres are studded there is rattle from those.


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## harnz (Sep 22, 2009)

mate you should start selling this as a service put extra pennies in you pocket could be a good little earner 8)


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## Fictorious (Sep 15, 2009)

Some measurements from the extremeties would be much appreciated for people considering this.


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## Jurpo (Jun 24, 2009)

I will post exact locations later.


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## Jurpo (Jun 24, 2009)

Distance on surface is 13,3cm left 8,0cm right. Once outer shell is drilled,it can be felt where center of tube is.
Easy to test smaller holes first. I used stick on wheel weights for temporary seal.
One solution for seal is ss bolts. Bolt head and cut washer inside. Nut,washer outside,once tight excess thread cut off. Make sure nut does not back out or..
I had can of zinc paint,i used it for extra seal.


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## luke89 (Sep 18, 2009)

umm like the look of this i mite cut mine up tomoz :roll:


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## harnz (Sep 22, 2009)

jurpo what neck of the woods you in wouldn't mind if you looked at mine for me


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## Jurpo (Jun 24, 2009)

Bit far off. I live in Finland. [smiley=santa.gif]


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## harnz (Sep 22, 2009)

loooooooooooooooooooooooool


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## dzTT (Mar 11, 2009)

fancy coming over for a "holiday" and doing a bunch of these then? :roll: :lol:


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## Jurpo (Jun 24, 2009)

No thanks. I like white christmas,where i live there is good chance of that. :lol: 
Besides i don´t want to take away diy joy from you.


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## harnz (Sep 22, 2009)

anyone over here fancy doing this for us


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## TT51 (Feb 28, 2009)

harnz said:


> anyone over here fancy doing this for us


I take it you are not to handy with tools :?

Really is a simple job even my kids could do it :lol:

If I was going to put a hole in my back box then I think I'd use a holesaw to cut about 30mm hole to really open it up. Then just patch over the hole in the outer casing. Once its all sealed and weathered you will hardly notice it.

The bigger hole would probably free up the exhaust gas flow a little as well and would barp barp


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## harnz (Sep 22, 2009)

:roll: :? errm no if someones already done it and knows exactly what to do why not let them do it?


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## Guest (Nov 29, 2009)

Anybody else tried this yet?

I'm tempted but want someone else to do it first


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## T3RBO (Dec 9, 2003)

Going by the original mod, is the sound effect the same if the fibreglass remains in place?

And to clarify, you are just drilling from one side into the pipe and not right through?


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## Jurpo (Jun 24, 2009)

What fibreglass? Holes are on chambers. Look at earlier pic.
Right through,so hole on both sides.


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## T3RBO (Dec 9, 2003)

Your first photo shows the back box opened up and the fibre glass removed

So if you need to drill right through both sides of the pipe work. Doing that with the exhaust still fitted will be a challenge, and how do you block the holes up on the other side, or is that not needed?


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## Jurpo (Jun 24, 2009)

Opened up pic is just to show what is inside. (I did not open up mine)
It is possible to drill underside only. Standard size drillbit is long enough to drill both sides.


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## Jurpo (Jun 24, 2009)

In cabin sound vid. 
http://s818.photobucket.com/albums/zz104/lerppa_photo/?action=view&current=s2.flv

Gives more realistic impression of sound level. (cam mic is not super at this,but not far off)


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## Guest (Dec 13, 2009)

Sounds good 

I'll probably have a crack at this at some point 8)


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## Farky (Oct 20, 2009)

Im re-igniting this thread, I picked up my guinea pig exhaust last week, Its had the centre box removed and replaced with a stainless steel straight through pipe section and Ive drilled holes in the top of my rear box so its not visible to anyone. :wink:

Jurpo, before I get the outer shell re-sealed, what size holes have you got drilled? mine are 11mm.
Im hoping with it de-silencered and these holes it will be loud on boost?..... 8)

Also anyone else thinking about doing this, here is a pic of mine with my measurements.


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## ecko2702 (Jan 26, 2009)

wait so if I am understanding this correctly you just drill 2 holes in your back box and it makes it sound better??


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## bennyboy1984 (Oct 31, 2009)

i have sitting at home, an OEM cat back exhaust, was only 20 squid  
gonna cut it open and decide what is the best plan, was gonna take the lot out and re-fill with exhaust wadding.
i dunno will find out this week when i get home.


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## Jurpo (Jun 24, 2009)

Farky said:


> Im re-igniting this thread, I picked up my guinea pig exhaust last week, Its had the centre box removed and replaced with a stainless steel straight through pipe section and Ive drilled holes in the top of my rear box so its not visible to anyone. :wink:
> 
> Jurpo, before I get the outer shell re-sealed, what size holes have you got drilled? mine are 11mm.
> Im hoping with it de-silencered and these holes it will be loud on boost?..... 8)
> ...


I have 12,5 and 10,5mm holes. With resonator delete yours is going to be louder than mine.  
If dropping exhaust is not too much trouble for you. Test it with temporary seal. I used stick on wheel weights.
I am going to fit 3" Downpipe soon. I´ll see what difference that will make.


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## Farky (Oct 20, 2009)

Finally got round to fitting my modified one this eve at the workshop, Ive now got a de-silencered center section and the holes drilled through the tailpipes inside the rear box, then welded outer skin back up, Im sure I can here alot more turbo whine/woosh out the tailpipes 8) It doesn't seem loud inside the car, deffo not droney at all, when i pulled up on the drive and had a few little test blips of the throttle, the girlfriend thought my exhaust was blowing........result


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## Camyam (Mar 20, 2009)

Been waiting to act on this topic but after much deliberating decided i could open holes in the bends from the outside down the exhaust tips! So took a long masonary drill bit, about 14inches long,15mm thick and powerfull drill and went for it  10 mins later after checking with a torch to see i was on target a breakthrough into chamber, then up a drill size to 25mm , 5 mins more and a neat hole bypassing all the internalls of the silencer.If your doing it yourself start on the drivers side its more of a bend and you feel your achieving something quicker!  
Now the sound , loverly tickover, very noticeably deeper and more of a 'pok pok', on the move more turbo sound and growl,but put the windows up and no difference inside from before, must be the tt.s exellent sound proofing.Iv'e done the wak box long ago and doing this to the exhaust is along the same lines, subtle OEM but well worth doing


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## Camyam (Mar 20, 2009)

Camyam said:


> Been waiting to act on this topic but after much deliberating decided i could open holes in the bends from the outside down the exhaust tips! So took a long masonary drill bit, about 14inches long,15mm thick and powerfull drill and went for it  10 mins later after checking with a torch to see i was on target a breakthrough into chamber, then up a drill size to 25mm , 5 mins more and a neat hole bypassing all the internalls of the silencer.If your doing it yourself start on the drivers side its more of a bend and you feel your achieving something quicker!
> Now the sound , loverly tickover, very noticeably deeper and more of a 'pok pok', on the move more turbo sound and growl,but put the windows up and no difference inside from before, must be the tt.s exellent sound proofing.Iv'e done the wak box long ago and doing this to the exhaust is along the same lines, subtle OEM but well worth doing


 Anybody else got their drill out yet


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## bak (Feb 10, 2010)

Great sound! I have 3" DP with sport cat and middle section

I think I will modify my 225 exhaust the next weekend. Is it the same if you drilled the OEM exhaust on it top or down? What is the measure of the diameter holes?


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## **wilkie** (Oct 28, 2009)

Anyone have any idea of the drilling locations on a 180 exhaust?


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## Jurpo (Jun 24, 2009)

Camyam said:


> Camyam said:
> 
> 
> > Been waiting to act on this topic but after much deliberating decided i could open holes in the bends from the outside down the exhaust tips! So took a long masonary drill bit, about 14inches long,15mm thick and powerfull drill and went for it  10 mins later after checking with a torch to see i was on target a breakthrough into chamber, then up a drill size to 25mm , 5 mins more and a neat hole bypassing all the internalls of the silencer.If your doing it yourself start on the drivers side its more of a bend and you feel your achieving something quicker!
> ...


So it souds good with big holes. Nice 8) 


bak said:


> Great sound! I have 3" DP with sport cat and middle section
> 
> I think I will modify my 225 exhaust the next weekend. Is it the same if you drilled the OEM exhaust on it top or down? What is the measure of the diameter holes?


Top or bottom both work. 11mm and up, whatever you like.


**wilkie** said:


> Anyone have any idea of the drilling locations on a 180 exhaust?


Probably not possible on 180 silencer.


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## bennyboy1984 (Oct 31, 2009)

i cut two windows on the top of the silencer above the two outletswith a slitting disc, then with a griding disc just cut big holes in the tops of the pipes, about 4" x 2.5" each side. then welded the two windows back in. painted the top with exhaust paint to prevent corrosion.

Now back on the car sounds a little V6'y and a nice rasp when driving, but not in your face noise.
also went straight through the MOT like it too!


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## nimaaltt (Mar 27, 2008)

sorry guys just to confirm again: drill right through? or just through first layer and pipe?


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## Jurpo (Jun 24, 2009)

nimaaltt said:


> sorry guys just to confirm again: drill right through? or just through first layer and pipe?


Both sides of pipe, regular drill bit is long enough.


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## nimaaltt (Mar 27, 2008)

by doing this can it have any negative impact on the car? or wont it make a difference? many thanks!


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## bennyboy1984 (Oct 31, 2009)

not made any differance to mine, just the tone and some burble


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## nimaaltt (Mar 27, 2008)

Hey guys I kinda attempted to do this this morning! I only drilled through the cover and pipe not all the way through because I wanted see what it sounded like... I've got the burble and it does sound abit deeper but honestly don't think I like it! It sound sorta like it's messed up but as it's descreet it's okay! Thanks for ur help!


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## Jurpo (Jun 24, 2009)

If it doesn´t growl on acceleration, it needs bigger holes.


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## Sh0x (Aug 29, 2010)

I stumbled into this via youtube (checking reviews for the 225) and Im tempted to try it too.

Anybody else done it / got any feedback since trying / last posting on here?


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## bak (Feb 10, 2010)

Do you fit a 3" DP finally?


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## Kristian_TT (Oct 31, 2006)

Anyone ells tried this?


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## bak (Feb 10, 2010)

I am waiting for to pass the ITV (spanish TüV) to try it but I will drilled the upper part not the botton


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## Sh0x (Aug 29, 2010)

Kristian_TT said:


> Anyone ells tried this?


bump


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## bak (Feb 10, 2010)

I have just did it 

I drilled on the top side as the picture that found here. The sound is not so louder but it is great when you accelerate from low RPM :lol:

It is easy and ship mod


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## kazinak (Mar 23, 2010)

i've drill mine


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## Sh0x (Aug 29, 2010)

Ooh I like that video (and how you run into action haha)

So did you remove the exhaust to drill it or just drill whilst fitted?

In your vid it doesnt sound bad on idle but in the one I saw on youtube it sounds really ratty tatty (as if its in the wrong gear sound) on idle and low revs? How does it sound normal driving?


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## SAJ77 (Nov 16, 2008)

Sh0x said:


> Ooh I like that video (and how you run into action haha)


+1

Car looks quick!!! 8)


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## bak (Feb 10, 2010)

You should remove the exhaust to work easier. The drilling is hard. And you must remove it if you drilled on top :wink:

Yes, on low revs the sound is ratty tatty, I love it  on normal driving by motorway or high revs the sound is similar an OEM exhaust, perhaps a bit louder but the prefect sound as I said is on low revs  


Sh0x said:


> So did you remove the exhaust to drill it or just drill whilst fitted?
> 
> In your vid it doesnt sound bad on idle but in the one I saw on youtube it sounds really ratty tatty (as if its in the wrong gear sound) on idle and low revs? How does it sound normal driving?


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## bak (Feb 10, 2010)

I upload my video  This is my Audi TT 180cv with the 225cv muffler modded


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## bennyboy1984 (Oct 31, 2009)

sorry but that does sound bad, like a wet fart.
you need bigger holes in it, i cut the box open and removed the bends that go to the tips, so its straight through.


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## Charlie (Dec 15, 2006)

bak said:


> I upload my video  This is my Audi TT 180cv with the 225cv muffler modded


Sounds a bit farty at idle :?

Charlie


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## bak (Feb 10, 2010)

I did that I read. The holes are 12mm diameter each. Bigger then? how much size?


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## John-H (Jul 13, 2005)

I've got my old exhaust to sell still if anyone wants a spare to try out - or if having tried it out they want to put it back the way it was! :lol:


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## bennyboy1984 (Oct 31, 2009)

i have cut out 6"-8" sections of pipe on both sides of the box. but i did it but cutting two windows in the exhaust.
i should of taken pictures!! will draw a diagram tomorrow! also took all the wadding out!


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## Sh0x (Aug 29, 2010)

worst case scenario you just have the holes welded up right?

Is it hard to remove the exhaust yourself?

I want to try it but need more persuasion!


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## dpbayly (Mar 16, 2011)

In case anyone is interested in a modified stock system (drilled holes) I've modified my old standard exhaust top job no lash and thought id see if anyone would be interested in it.

Here's a link to ad:

viewtopic.php?f=15&t=204590


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## Sh0x (Aug 29, 2010)

TT51 said:


> harnz said:
> 
> 
> > anyone over here fancy doing this for us
> ...


Do the holes go through the top of the backbox, or the lower side (the side you would see if you jacked the car up?)

Am I right in thinking you dont need to cut anything, just a hole through (which ends up going through the internal pipe) then you weld up the outer hole which is visable?
Or have I got this all wrong.... :?



Camyam said:


> Camyam said:
> 
> 
> > Been waiting to act on this topic but after much deliberating decided i could open holes in the bends from the outside down the exhaust tips! So took a long masonary drill bit, about 14inches long,15mm thick and powerfull drill and went for it  10 mins later after checking with a torch to see i was on target a breakthrough into chamber, then up a drill size to 25mm , 5 mins more and a neat hole bypassing all the internalls of the silencer.If your doing it yourself start on the drivers side its more of a bend and you feel your achieving something quicker!
> ...


 Anybody else tried camyams method? Camyam, hows your method holding up?


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## kazinak (Mar 23, 2010)

Camyam said:


> Camyam said:
> 
> 
> > Been waiting to act on this topic but after much deliberating decided i could open holes in the bends from the outside down the exhaust tips! So took a long masonary drill bit, about 14inches long,15mm thick and powerfull drill and went for it  10 mins later after checking with a torch to see i was on target a breakthrough into chamber, then up a drill size to 25mm , 5 mins more and a neat hole bypassing all the internalls of the silencer.If your doing it yourself start on the drivers side its more of a bend and you feel your achieving something quicker!
> ...


 Anybody else tried camyams method? Camyam, hows your method holding up?[/quote]

i did ,i have use 20mm drill bit


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## Sh0x (Aug 29, 2010)

Kazinak - can you do it by only jacking up the car? Do you need to remove the backbox?


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## kazinak (Mar 23, 2010)

Sh0x said:


> Kazinak - can you do it by only jacking up the car? Do you need to remove the backbox?


have tou read this
Camyam wrote:
Been waiting to act on this topic but after much deliberating decided i could open holes in the bends from the outside down the exhaust tips! So took a long masonary drill bit, about 14inches long,15mm thick and powerfull drill and went for it 10 mins later after checking with a torch to see i was on target a breakthrough into chamber, then up a drill size to 25mm , 5 mins more and a neat hole bypassing all the internalls of the silencer.If your doing it yourself start on the drivers side its more of a bend and you feel your achieving something quicker! 
Now the sound , loverly tickover, very noticeably deeper and more of a 'pok pok', on the move more turbo sound and growl,but put the windows up and no difference inside from before, must be the tt.s exellent sound proofing.Iv'e done the wak box long ago and doing this to the exhaust is along the same lines, subtle OEM but well worth doing


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## Sh0x (Aug 29, 2010)

Yep, so you did it the same way as camyam..

Where exactly did you guys start drilling?

If I take a picture of the underside can you show me??


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## KammyTT (Jun 28, 2006)

Jurpo said:


> Oem Air box. Tyres are studded there is rattle from those.


I meant see the video from the link

Sent from my iPhone using Tapatalk


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## dpbayly (Mar 16, 2011)

My modified standard exhaust is still up for sale now a lower price if anyone is interested:

viewtopic.php?f=15&t=204590


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## John-H (Jul 13, 2005)

I've still got my exhaust for sale too: 
viewtopic.php?f=15&t=202510&p=1990046#p1990046

I'm currently contemplating cutting it in two for someone but it seems a shame to do so.


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## Sh0x (Aug 29, 2010)

Hello guys can I ask,

Would I be able to drive the car to a welding place If I drill the 3 holes in each side of the backbox and leave the holes on the outer layer uncovered (I would get the outer layer welded up) ??

Or would that sound like a tank and damage the car :?


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## Fictorious (Sep 15, 2009)

It won't do any damage, and will just sound a bit like the exhaust is blowing, but it's not too loud really.


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## Camyam (Mar 20, 2009)

An update.....
Couple of weeks ago drilled out further to 30mm ,thats as far as you could go with this method the slight curves of tail pipes start to foul the drill bit sides, its getting brutal by now and firm grip of the drill is needed!
But the sounds improved ,a deep growl on acceleration easily heard inside, but a steady throttle and its OEM, no drone,worth doing but it looks insane shoving a massive drillbit up its rear!


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## Johnclem88 (Aug 22, 2011)

Sorry to relite this thread...But I'm thinking about doing this, along with removing centre box and 3" downpipe and decat/or race cat.

My question is, what bore is the OEM Catback, as to me putting a 3" DP and DECAT on and having a smaller diameter cat back is a bit counter-productive...

Cheers


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## nathan88 (Oct 18, 2009)

Good thread. [smiley=book2.gif]


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## bennyboy1984 (Oct 31, 2009)

i have a rear section sitting in my shed if anyone wants one???
i am in lowestoft


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## nathan88 (Oct 18, 2009)

bennyboy1984 said:


> i have a rear section sitting in my shed if anyone wants one???
> i am in lowestoft


Price?


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## reece1591 (Sep 25, 2013)

Decided to bring this back to life.......

Looking for more noise from the tt after having full milltek on my mk2 Leon I'm missing the burble.

Seem the best way is to ram a long drill bit in the tip to drill hole either side correct?

Going to give it a go see what happens if not much change will get middle box cut out


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## J•RED (Feb 10, 2013)

I did this a few months ago. Iv got a deeper tone on idle and a nice noise when I boot it  iv left my resonator in place. The noise is not loud but gives it a more sportier sound.

Basically I cut all the tubing out you see in this picture. 









Then welded it back up.

Sent from AutoGuide.com Free App


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## uv101 (Aug 17, 2013)

great thread!

Given the total lack of availability of any 3.2 system, the crap that Milltek wang together with substandard quality control (if any) and schoolboy welding started me thinking about modifying the std system.

I've got a MK4 R32 decat and non res pipe on the way from R32OC forum after someone on here put me onto the guy selling them.

I missed a rear box on ebay the other day for £15! wasnt too far from me either :evil:

Would be good "adjust" baffles in the rear box!


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## J•RED (Feb 10, 2013)

Don't buy it, build it!  can imagine the v6 with baffles adjusted sounding very nice!

Sent from AutoGuide.com Free App


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## reece1591 (Sep 25, 2013)

will be doing this tomo if i can find big enought drill bit just going to drill down the tail pipes for ease of access see what happens


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## ScoTT (Mar 13, 2012)

so basically ram a large drill bit up your tailpipes?


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## uv101 (Aug 17, 2013)

I was thinking about something a little more involved than just drilling a few holes!

More like as shown in the pics, cutting a section open and then removing/shortening the internal baffles to make the box less restrictive.


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## theblob (Jul 11, 2009)

Decided to give this a go, went for the 14" drill bit straight up her rear end after about 10 mins both pipes were done. Went for a final size of 25 mm and must say very impressed how the standard exhaust sounds nice burrble and not at all loud from inside the cab. So all in all glad i did it 

Rob


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## John-H (Jul 13, 2005)

Rear 225 box going spare if anyone wants to experiment.


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## Chris.od (Sep 2, 2013)

I'm interested John, what you after for it?

Cheers, Chris


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## eddy_rooney (Feb 18, 2014)

im getting my drill out the weekend. haha


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## John-H (Jul 13, 2005)

Rear 225 box still going spare if anyone wants to experiment.


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