Otherwise if you wanted it in an Airbox you may have just as well bought a sports panel filter.
I went for a K&N cone filter as I knew that they give better increases in torque over the sports panel filters. Additionally, the reason I went for this particular one was because I was on a budget (I don't have hundreds of pounds to throw at my car unfortunatly, as I'd have a V not a 182 if I did!)
I am not after serious increases in horsepower - I know that a filter change would never have that effect. Truth is I felt my car was getting a little breathless towards the top end so felt like a little more torque would help - the K&N sounds nice with its induction noise also. It's done that job, but I was just enquiring what effect the cooling ducts would have, and if the effect outweighed the effort of fitting one.
I've had my question answered, and a cold air duct would be canceled out by the hot air of an engine bay (as I thought), so an enclosure/sheilding would help with this.
Ok, rant over.
Don't get wound up bud, every forum has the know it all (well, they think they do), who likes to put people down. Plus, if you were worried about fuel economy, you wouldn't want to do 'power' mods, would you ?!
Everyone needs to understand that a production car is always a build with a large amount of compromise and, that they can always be improved upon.
If you have an open type filter like the 57i, you'll always suffer from some sort of warm/hot air induction, no matter what you do, unless you put it in and enclosure.
If you get a cold air feed to it, you'll get the benefits whilst on the move but, when you stop at lights etc... you'll just be sucking in warm under bonnet air.
When you are moving though, a decent sized cold air feed (70mm+) will help you maximise the better flow capabilities of the K&N filter.
As for enclosing it, the filter is designed increase air flow capacity into you engine, nothing else. It doesn't know or care whether it is enclosed or not. If you did enclose it though, you certain to see benefits, as long as you design the enclosure well. With this, what you're trying to do is not restrict the new found flow capacity of the 57i. So, regardless of the actual enclosure size, you'll need a good sized air feed into it.
As you're on a budget, I'd discount the idea of building an enclosure.
If it were me, I'd sell the 57i and go for a K&N or Green panel filter, in your stock air box. Seal off the hot air intake, mentioned above, and enlarge the cold air intake, connected to a nice large diameter cold intake pipe, to the front of the car or, somewhere it won't suck up warm air.
I'll be doing something similar when the other halfs R27 turns up.
