I removed the cover on my airbox a few months ago. My "S" is a not a daily driver and during the winter it's just a few short trips per week, i don't think i noticed any power loss but than again I'm not doing any summer driving so maybe heat isn't building up under the hood leading to heat stroke or is it soak?

Anyway what do you guys think? I'll be buying a new intake soon, but not for another few months.

 

Import tuner showed a +2 hp gain just by removing the top of the airbox. Of course that wasnt run for a few hours, but for just a quick drive it should add a tiny bit of power

 

Try this. Just leave the front of the air box open and the back pinned. This will give you a nice sound without heat soak. If done right there should be a crack about a
| | this wide. To make sure it stays i put the clamps in the way of the lid.
There is a big difference in throttle response with it off.

 

This is only approximate: A loss of 1 HP for every 3 degrees of intake air temp rise. Your engine bay, during hot days in city traffic can go up as high as 70*C.

 

Leave it on!


Just gut out all the plastic inside.

 

In my Type R the bottom half of the airbox fell off while I was doing a Solo 1 event. The first day my lap times were very consistent. I took the corners better each lap, but my times stayed the same. My fastest lap was usually my first. The second day I fixed the airbox. Each lap got quicker by a couple tenths.

You might gain a couple horse power or two on a dyno, but after a lap or two you will lose a fair bit. Either way it's really not enough to notice unless you're being timed.

 

I really noticed the loss in throttle response with the cover off.

I had it off for around a month. Once I put it back on, I couldn't take it off again!

 

I had the top cover off for a day but put it back on. The induction noise is nice, but that weird humming noise bugged me. Time to start shopping for an intake I guess.

Proud new owner of an 03 gpw/tan with only 7k miles!!!

 

It's weird that everyone claims there is a decrease in HP when you take the top off... However, isn't the AEM V2 a short ram intake? How about the AEM V1 Short Ram? These are marketed to consumers as a HP increase. Essentially, isn't it just about (key words: just about) the same thing if he took the top off his current intake?

 

I have dynoed my car with the cover open and I gained 2whp low mid but I lost 2whp during up top.