10 replies to this topic

[Dusky]

Here I am again ;)

To those who drilled their airbox before: where did you dril the hole(S), how many and how bad was the noise?
Im trying to figure out if 1 big hole would be better than multiple small ones, and where I should drill/dremel it to give the best performance without too much noise

Cheers!

[Fast Ivan]

will it make much difference to performance?

[Dayo76]

when i drilled my air box it made it quieter for some reason, i drilled holes around where theres a bit of an indent where the throttle cable is i think i put 5 or 6 13mm holes in it only because 13mm was the biggest the drill could take. i dont know if its the same air box but its off of a mk 3 

[nicklouse]

I would not bother. just make sure you are ducting cold are to the inlet.

[Dusky]

I think it would improve things a bit because the biggest limiting factor I have in the box is the big snorkle wich has an area ( at the entrance) of 1060mm² , where the elbow has an area of around 1900mm² and the 44mm carb throat is 1520mm² .

Another option might be to try to drill/enlarge the snorkle?

cheers

[tiger99]

Aerodynamics are not simple and intuitive, which is why drilling holes made one quieter and why drilling holes in the wrong place will reduce performance. You may be best to leave well alone, or prepare for a very long program of trial and error. Or maybe copy from one that has been proved to work on a rolling road on the exact same engine...

[1314cc]

Check out www.calverst.com , look under technical info then air filtration. You'll see everything you need to know, according to his tests a drilled box with kn came out favourably

Edited by 1314cc, 20 June 2016 - 12:44 PM.

[nicklouse]

Check out www.calverst.com , look under technical info then air filtration. You'll see everything you need to know, according to his tests a drilled box with kn came out favourably

http://www.calverst....air-filtration/

[blacktulip]

4 holes 3/8" diameter at the front as you look at it then chamfer the edges to eliminate whistling

Edited by blacktulip, 20 June 2016 - 01:51 PM.

[monkey]

Check out www.calverst.com , look under technical info then air filtration. You'll see everything you need to know, according to his tests a drilled box with kn came out favourably

http://www.calverst....air-filtration/

Interesting reading!

[Dusky]

I've read that article a few times before, but he's not so clear on teh noise.