I'm looking for an inexpensive mod to add a few HP and MPG to my 2004 Bonneville SE. I've read about gutting the airbox -- and that seems like a good idea. I've also thought about simply taking the airbox out of the equation and simply putting on a cone filter.

Will the cone filter (sans airbox) work just as good?
What are the advantages / disadvantages?
Which brand is better -- keeping "inexpensive mod" as the theme?

THANKS!
CharlieJ

There'* no significant gain either way. With the gutted box/cone you'll get more air into the engine that'll allow it to run a little more efficiant. Some guys say the cone allows more air into the engine then the gutted box. Bottom line: More air equals more sucking noise which makes folks believe car runs faster. All in all there'* posts that claim a intake mod alone yields about 5-7 hp max.

THANKS!

I'm looking to give the car to my soon-to-be 16 yr old daughter, so I don't care if it goes faster. However, I would like to get more MPG out of it. While I have it (these last few months), I'd like to enjoy the power increase, if any (thus the reason for asking about HP).

BTW, the airbox on my car looks nothing like the pictures I've seen on the forum. Mine is HUGE -- and it looks to be two-piece.

I gutted the airbox on a 1998 SE. It made the car noisier, particularly at start up, but gave me no noticable increase in power and no measurable improvement in fuel economy.

In my opinion the factory airbox is not a constraint on either horsepower or fuel economy. In the first case it would only be remotely possible at wide open throttle near max RPM for the airbox to come into play; and in that condition several other factors would be more important.

In the second case, fuel economy is controlled via a feedback system including the O2 sensor(*) and computer programming; so if the system was restricted the ECM would adjust the air fuel ratio to deliver the right fuel economy.

Back in the bad old days (when carburetors ruled the earth) restrictive air intake, usually caused by poor maintenance and clogged filters, power and economy could be improved by cheap and simple means. Today with modern engines, computer controls and CAFE standards, all you'll get by gutting the airbox is more noise.

If that'* your cup of tea, break out the dremel!

neither.