Air Filter Size

[chrisryder]

Hi there, i'm looking at picking up a K&N filter for my 1275 engine. i've got a HIF44 carb, but there are choices for filter depth. 45, 54, 63 or 83mm depth. i'm guessing the choice is normally for installation limitations. with the minor, there's not much of a limitation, so would bigger be bestest to give biggest filtered area?

Any advice much appreciated!

[chrisryder]

having said that, the 83mm looks rather large from the picture!
[frame][/frame]

[bmcecosse]

Bigger IS better.

[chrisryder]

thought as much, wasn't sure if anyone had tried an 83mm one and had any problems, or used a 63mm one and wished they had a bigger one! i suppose an 83mm one will give more room for a ram pipe or a short stack inside

[bmcecosse]

To get any real advantage - you must either file the mouth of the carb into a nice radius - or fit a stack thing - to eliminate the vena contracta.

[chrisryder]

yep, i have access to a vizard bible, and a lathe, and stainless billets... so i may use vizards research and make myself a radiussed ring to go around the carb throat

shame really, as it'll never be seen, but it should make a good differece!