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Discussion Starter · #1 ·
After having had this mod sitting under my desk at work for 10 months, finally...

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Thought I'd make it just that bit more stealth before fitting:

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Unfortunately I want to take it off and put the factory system back on already - I think this is the biggest and most expensive, or make that first modding mistake I've made. It sounds bloody awful at anything above idle.
 

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[:O] You dont like it! [:O] Making me think twice now! Or could the noise be increased due to your induction kit??
 

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oh dear! thats not good! unlucky! is that the Milltek discrete back box by any chance or something else? heard the discrete one can sound loud for some reason! [:S]
 

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[:(][:(] thats no good mate, are you going to give it a week or 2 for the noise to settle a bit once it's bedded in? I love the stealth paintwork though [y]

you also have the same intake cleaner spray as me, how powerful are those aerosols??!
 

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The noise isnt anything to do with all those currys you are eating is it...still,you could always try stuffing a few neons up there to muffel the sound whilst making it look wikid at the same time. [;)]
 

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cant believe after having it under your desk for so long you finally fit it you dont like it, thats just not funny. If i remember right its a Miltek system aint it, i might be interested in taking it off your hands if you do decide you want rid. PM if your interested.
 

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Sorry to hear that shiuming, i only have good things to say about my milltek. Although mine isn't a discreet version like yours, it quietened down & mellowed a lot once it carboned up (at first I thought it was loud too). Now its no louder than standard when cruising, but under WOT it is louder but only a sporting tone (no corsa/saxo 'Paaaarp' here, thank-you!).

Of course, from the many threads i read before buying my milltek, i think some people have said they found the discreet versions uncomrtfortably boomy. All I would suggest is to give it a little time to carbon up, and then if its still not for you, then swap back to standard.
 

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Discussion Starter · #15 ·
[:O] You dont like it! [:O] Making me think twice now! Or could the noise be increased due to your induction kit??
It's not the induction kit, the noise from that is very distinctive, a very fruity burble which is real nice to listen to, which is why I'm well peed off that the exhaust now drowns it out almost totally [:(] It's basically the stock sound, amplified.

There are two main factors affecting the sound. First of all the bore of the pipework - the Milltek is only about 15mm larger diameter than stock, this deepens the sound. Secondly, the OEM silencer boxes - certainly the centre box, can't see the back box without cutting it open - use carefully spaced baffles to dampen the sound by wave cancellation, whereas the Milltek, both centre and back box, use perforated cores (cheese grater shaped like a toilet roll), which are then surrounded by material like steel wool to dampen the sound by wave absorption. It's more or less a straight through system and from what I can tell lets out far more sound. I did some tests before having it fitted, I took the two silencer boxes and played various sounds through them and listened at the other end to get an idea of how they modify sound. By the way, this should help explain why I take so long to fit stuff [;)]

I don't know if a baffled system has more scavenging effect (due to the longitudinal interaction between opposing pressure waves versus absorption into the side walls) - a large bore straight through system certainly doesn't, you're just peeing in the wind.

oh dear! thats not good! unlucky! is that the Milltek discrete back box by any chance or something else? heard the discrete one can sound loud for some reason! [:S]
Yes it's the discreet, I wanted it to look standard, but sound maybe just a bit more aggressive. It's been discussed to death on here but I don't think anyone has a real answer as to why the discreet should sound so significantly more boomy. The pipes are angled down as well not pointing straight down like the factory system, so I don't think it can be to do with sound being trapped under the valance - the pipes are not high enough or far inside enough for this to be the case. Surely the back box itself must be the same between the 4Mo and discreet versions...

WOOOOOOOORRRRRRRRRRRBBBB

VRRROOOOOOOOOOOOOMMMMMMMMMM
It's not that type of sound at all (Ripspeed Coffee Can Hollow Fart Special). It's a solid, tiresome boom, like being strapped to a subwoofer playing a continuous tone. No rasping, no throbbing engine type noise. Although it does pop and growl a bit at low revs.

[:(][:(] thats no good mate, are you going to give it a week or 2 for the noise to settle a bit once it's bedded in? I love the stealth paintwork though [y]

you also have the same intake cleaner spray as me, how powerful are those aerosols??!
I'm going to have to leave it on for a bit now, no time or money to revert back to stock. LOL @ the carb cleaner, yeah I also use it for exterminating flying insects and pests! Incidentally, I used to work for the company that designed and hosted Wynn's UK web site </useless fact of the day)

I hate loud exhausts. You still got the old one?

By the way, you got the same hairdryer as me! [:p]
Yes still got the old one... under my desk at work!

I don't need a hairdryer, grade 1 back and sides, me.

I cant see anything

At work and they block Most pictures [:'(]
So you click on one of my threads, in Members Rides no less?! [:p]

Sorry to hear that shiuming, i only have good things to say about my milltek. Although mine isn't a discreet version like yours, it quietened down & mellowed a lot once it carboned up (at first I thought it was loud too). Now its no louder than standard when cruising, but under WOT it is louder but only a sporting tone (no corsa/saxo 'Paaaarp' here, thank-you!).

Of course, from the many threads i read before buying my milltek, i think some people have said they found the discreet versions uncomrtfortably boomy. All I would suggest is to give it a little time to carbon up, and then if its still not for you, then swap back to standard.
Thanks for the explanation. I'll live with it for a bit now. Actually it sounds like a bad-ass old skool modded Mk2 GTI, and with the black rub strips and old-ish style BBS cross spokes it kinda looks the part too.

I've sent an e-mail to Milltek to quiz them about their sound absorption material and the boominess, let's see what they say.

I do have another issue right now and that is when I asked the garage to sort me a new battery, they were a bit too helpful and fitted it for me as well (fair enough I didn't tell them not to fit it, but they know me quite well and I always buy parts, but I had said I wanted it as a spare), so my ECU has been reset as well. Right now my car runs like poo and I don't know how much of it is down to the exhaust and how much of it due to the ECU reset, I've thrashed it for 50 miles and pick up is better in 1st and 2nd now, but in 3rd... where's my mid-range and top end gone?! Contrary to reports I've read here, it doesn't feel more revvy at all, it just makes the noise and doesn't shift. Gone is the point-and-squirt eagerness.

I think this exhaust has added turbo lag to my NA car!

Oh well it looks all nice and shiny through the back wheel.
 

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Discussion Starter · #16 ·
Another thing that pees me off... why are the flanges on the hangers about half and inch too far apart to fit the rubber mount properly, allowing the box to slide left and right?! How difficult is it to make parts that fit properly?!
 

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I used cable ties to stop mine sliding from side to side, it'sa shame to hear you're having so many problems, hope you get them sorted soon
 

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Discussion Starter · #18 ·
Tom, which centre section do you have, resonated or straight through? Also did it really quieten down noticeably?

I have to say, I really do notice how my factory system, at 5.5 years old, does sound quieter than when it was new. It's a very quiet system indeed. Hope the Milltek doesn't take that long [:O]
 

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Discussion Starter · #19 ·
cant believe after having it under your desk for so long you finally fit it you dont like it, thats just not funny. If i remember right its a Miltek system aint it, i might be interested in taking it off your hands if you do decide you want rid. PM if your interested.
Cheers dude I'll bear that in mind [Y]
 

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I did some tests before having it fitted, I took the two silencer boxes and played various sounds through them and listened at the other end to get an idea of how they modify sound. By the way, this should help explain why I take so long to fit stuff [;)]
I know I shouldn't laff but I can just imagine you with your milltek on your desk with a triangle next to it and some elaborate heath robinson esque contrapation to allow you to ring the triangle from t'other end of the milltek so you can hear it [:D]

Regarding peeing in the wind - Perhaps you could flow some liquid through it and measure it's velocity on exit relative to it's velocity on entry and decide how it's being arrested on it's path through the aforementioned pipe, thus determining how it MAY be changing the sound.. [;)]

sorry bud, I couldn't resist..
 
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