I had the lid off for nearly 2 years and can't say I really noticed any real power loss. I raced an 02 with with the airbox on and the difference was negligable.

 

Kmpowell got a rolling road read of 246 hp (or theres abouts) with his lid off so it can't be making that much of a difference.

 

Maybe it varies from car to car?

I took mine off last night for the first time. Driving to work today, the difference in performance was night and day (and it wasn't particularly hot today). I loved the noise but no way can I live with the power drop. It went back on tonight...

I've got an AP22 performance meter somewhere so I might dig it out and get some comparisons when I get time...

 

throttle response is 'spongy' with the airbox off......

 

And with air from the fans blowing straight onto the filter, rather than the soaking up the hot air from under the bonnet, so would probably in that case give you more power.

So the moral is run without the air box lid and have holes cut in your bonnet, anyone fancy a nice air scoop or just run with no bonnet, but watch for when it rains

 

the power loss is when you put your foot suddenly down - the acceleration simply isnt so full on. If you lardy drive, doubt you will notice it.

 

This is exactly how I'd describe it. I've had the lid off for a couple of weeks now (howling through underpass tunnels around town in 2nd with the roof down is awesome!).. but the lack of throttle response is starting to bug me now.

Performance seems slightly down, but this is probably due to the above mentioned "soggy" throttle.

I expect it'll go back on in a week or so, which is a shame because I love the noise! (and can't afford a snorkel!)

Tim

 

well ive put it back on now. its too annoying. my engine managment light has just turned on. ive only had the car 5 days. ive hot to take it to honda to c wat the problem is

 

Had my airbox lid off since I fitted the rad cover. Yes the throttle is soggy and I can really notice this. That will be why I go back to stock or get a CAI.

 

So there is a difference though!! If another stock car with the lid on pulled even just one car length ahead of you then that is significant enough. Times that one car length on every straight of a track then again by 5 laps and suddently your car is sh!t-slow by comparison.