Milltek question again

[blelock]

I am busting to buy a milltek exhaust but dont want to car to be really loud. So do you guys recommend

1. Milltek non res with valves
2. Milltek res with valves
3. Milltek res with no valves

[edge]

1. Milltek non res with valves

best of both worlds.............

[RSKiwi]

If you can afford it

Number 2

I find mine plenty loud enough valved and resonated. It is ideal when cruising along as it is nice and quiet until you put your foot down and the sound is unleashed. I do have a ludicrously loud airbox so I may be a bit skewed by that.

[neilc]

Go for resonated with valves as the other guys suggested. Just had one fitted last week and done 750 miles in the last 10 days with it. Perfect combo of burble with valves closed and NASCAR with valves open.

Try Roadrunner motorsport , they are well priced I thought.

Neil

[blelock]

Is the exhaust any louder with a res with closed valves than a standard exhaust with the valves open?

[RSKiwi]

Is the exhaust any louder with a res with closed valves than a standard exhaust with the valves open?

Yes. But by how much I couldnt tell you or even begin to guess at.

[edge]

Amended mine, ment to select NON res

Best option, hit the national meet and listen to all the option!

[Nobber]

Sorry but I can't remember who it was but someone posted decibil readings from a Non Res Valved over Std. I seem to remember that STD with open valves was 70db in the cabin and Non Res valves closed was 74db, so not a massive difference.

Hope this helps. I'll try and find the thread.

[Nobber]

http://forum.rs246.com/viewtopic.php?f= ... rt=15#wrap

[RSKiwi]

Sorry but I can't remember who it was but someone posted decibil readings from a Non Res Valved over Std. I seem to remember that STD with open valves was 70db in the cabin and Non Res valves closed was 74db, so not a massive difference.

Hope this helps. I'll try and find the thread.

Just to nerd out for a second *pushes imaginary glasses up bridge of nose*

A 4db increase is actually pretty significant. 10db is perceived by a human to be roughly double the loudness (often mistaken for 3db increase) so 4db is definitely going to be noticeable. (not that you implied it woudlnt be) primarily the 'intensity' of the sound as opposed to 'volume'.

Thats not very clear is it?.....Ill get my coat....

[Nobber]

another 'nerdy' friend of mine said something along those lines about db increases being considerably more than they look on paper. I just pretended to understand what he was on about and promptly ignored it because I want the non res!!

[P_G]

Increases in sound intensity and volume is not linear essentially.

[mark758]

Had a F430 follow me down the last stretch to Goodwood FOS; we parked up next to each other - he was full of praise....'I didn't think an Audi could sound like that'

[adsgreen]

I'm one of those who got confuse over this.
+3db is a doubling of the sound pressure intensity.
However the human ear has some funky evolutionary adaptations to be able to deal with a wide range of sound pressures. So this isn't interpreted by the brain as double volume. It's approximately 8-10db that the human eat recognises as double volume which represents over 8 times sound intensity.
dbA is the db scale but weighted for human hearing frequencies.

My view is that the non res valves is by far the best option.

[gareth_oau]

Ive just gone non-res non-valved and loving it. i dont find it too loud at at all, and nor does the other half.

ive just spent the weekend crusing round the countryside at 100kph + and the noise wasnt intrusive, nor was there any drone.

the only thing I did notice was the number of approving/admiring glances whereever I went.

Going valved is a big step up in price where you could throw that same cash somewhere else