I can't back this up with dyno numbers but my butt is telling me that it is better to run w/o the lid.

Has anyone verified this?

 

PM Zerobanger.

 

well..

I ran extensive tests with the rx7fashion intake box which is made from the same design. I did tests at the drag strip while ramming air into it, and without the ram air effect. I have about 50 maybe 60 timeslips from these tests that I did.

one day I had 5 runs at sacramento raceway. During those runs I trapped 109.X to 110.X 3 times.

I trapped 107.X and 108.X 2 times.

The two lowest trap speeds I had were with the lid off. This is hardly conclusive but its probably the closest thing you will get to a comparison.

BTW, your butt dyno must be hella sensitive.

 

With the lid off, you may flow slightly more air into the box, but it wont be much. The problem is that you are pulling in warm air. That totally defeats the purpose of a cold air intake

 

Sometimes the "right" sounds make a huge difference in our perception of performance.

Can you hear a difference between lid on and off?

 

why do you want a CAI if you take the lid off? it'd be almost the same as a cone filter attached. on a drag strip you DO get more HP with a cone filter/hot air intake, probably because air doesnt have to be pulled in through those air intake tubes. but for daily driving, sitting at a stop light it is a bad thing i would think.