Open Air Kits

What is y'all's advice regarding open air kits? I have been researching the internet and find some conflicting reports. I know that open air will allow for more air to pass through; however, once the engine becomes hot the air filter will suck in hot air which is not always necessarily good. It seems as if open air kits with heat shields are the way to go, but I wonder do those shields really prevent heat from being sucked in?

Has anyone just dropped in a direct replacement air filter (such as K&N) and noticed a difference?

What's the best way, open air or direct replacement air filter (keeping the filter box)? thanks!:sun:

Hi,

I am currently having the same dilemma. I am waiting to install a K&N cone which I got three weeks ago, but after trawling through dozens of web sites and various technical white papers it seems that a cone filter WITHOUT a heat shield is only going to produce approximately +2 BHP on a very, very optimistic day! A cone filter will also definatley let in more dust particles to the engine than the standard air box, but this is a secondary concern to the BMW modder who wants to speed up his/her car. A cone with a heat shield will not suck in any air from the hot engine but on a hot day will suck in warm air from outside!!! It's a case of "You're damned if you do, and damned if you don't". In the mean time I'm going to look for a UK company who supplies heatshields compatible with the E36 325i K&N cone that I have 'cos even after all I've said I definatley want that beastie under my bonnet.

Good Luck

Anyone else have any opinions or input concerning open air kits?

my opinion? they are not worth the money, but if for some reason they make you sleep better with the knowledge you've done whatever it takes to make your car faster... then go for it!