Modifying Air Box?

[zola]

Where's the best place to drill the holes on the air box for more air intake and do you notice a real difference? I know not to drill them at the side as this may cause hot air from the cam belt if that's true?

[johnatstroma]

i would suggest just to buy an induction kit to replace your air box.
Drilling holes in your air box just makes a bit more noise than a standard air box. does improve th car and have heard it can also make ur car worse sometimes too.

Any way fitting an induction kit would make ur engine bay look alot better

[Alex]

Not necessarily. One car magazine (Fast car IIRC) tested a GTE with a drilled airbox and performance filter (K&N) against various top induction "kits". Suprisingly the drilled airbox performed better than all of the others.
Not sure if the site is still up but www.tomstickland.co.uk had the results on

[Alex]

If you do decide to drill your airbox, then make sure the air still has to pass through the filter before it gets into the engine (i.e. drill them on the bottom of the box.
The site is up, and it was Revs magazine

http://www.tomstickland.co.uk/astra/astradata/gdata.htm

[zola]

Thanks for the advice people, much appreciated.

Paul

[Jules]

Revs magazine did a test ages ago on a GSi Nova and the best result were from a Jetex panel filter and drilled airbox, also Total Vauxhall did something similar a year or so ago and got the same results - they used a Blydenstein modified airbox rather than a drilled standard one - but I expect similar results could be achived by drilling the standard one and removing some of the junk restricting airflow to the airbox.

Also imo the standard airbox looks better than a cone filter induction kit - but that's just me!!