This is my air filter, as you can see most of the forward part will be up against the inside of the bonnet when fitted.


Air Filter
I am contemplating making a bonnet hole, just like the one below.



Somebody elses air filter hole
If I left it as it (without a hole) does this mean impared performance?
Will I notice any increase in performance with a bonnet hole??
Are there any other alternatives to making a big hole in my bonnet??

quote:

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Originally posted by Slater
If I left it as it (without a hole) does this mean impared performance?
Will I notice any increase in performance with a bonnet hole??
Are there any other alternatives to making a big hole in my bonnet??

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I would put a hole in it tbh but the main points doing so I’d say are

1) you'd get cold air into the engine so more power

2) unrestricted flow into the trumpets, yet more power

3) however in the rain you might get increased carb icing

4) some say the turbulent air can cause poor running at high speeds with bike carbs

5) you'll get a lot more induction noise and hissing (not a bad thing if you like it)

[Edited on 8/6/09 by Mr Whippy]

is your filter hard up against the inside of the bonnet? Either way air flow will be impeded. If its being squashed then hole as in pic might be the way to go. If it wont poke through then you could get inventive with the style of the cut out. I have some motorsporty looking triangular cut outs that i then bonded mesh to the rear of. However for the new bike carbs filter i had no choice than to cut hole and let it poke through.

I was worried about it getting soaked when it rains but its never been a problem.

Sorry to hijack the post, but i have exactly the same issue.
I have now decided to cut the hole to let the carbs get the air they need.
Could anybody be kind enough to advise me of the best and most neatest way to do this

what about an airbox, with a directed cold feed from infront of the radiator?

this is my plan for my new engine

here is what i did



HTH's