Me too...I was driving top-off in 60-70 degrees weather...So I put it back on...I absolutely agree that it sounds much more rumbling. Pretty cool...Maybe I will try again when we have 40-50 degrees weather!!!

 

This isn't relative to the discussion. Heffeme's question is related to the initial pressure drop and system dynamics of the filtration system. The throttle body is the metering device itself and it's area is variable depending on throttle position.

 

[QUOTE]Originally posted by Bigal:
[B]This isn't relative to the discussion.

 

Watchout!!!Here comes FLAMES

 

flames are fun aren't they!

 

first of all, thanks to mingster for the awesome info, and to all that responded.

Now to address cdelena and bigal's discussion. first of all, i didn't actually measure the size of the opening in the airbox, and i also don't know the size of the throttle body off hand. i do think that bigal's argument has value. the dynamics of the whole air box/filter/intake etc is EXTREMELY complicated. the fluid dynamics involved with the system was probably calculated by a wonderfully brilliant honda engineer.

cdelena, pulling air through a restriction (the "5 by 3" hole, and around a few corners) before it even reaches the throttle body does provide more restriction. with that in mind, my first post was about power (of course) so whatever anyone wants to consider a part the issue, feel free to comment.

one more thing, aren't there just a few thin little cuts (in the plastic piece above the radiator) just in front of the airbox inlet for fresh air to come in?

maybe somebody out there can calculate theoretical gains in considering out side air temps???? any engineering phds?

 

Not much new to add but I do notice a drop in performance with the top off. And that annoying drone as well.

 

[QUOTE]Originally posted by heffeme:
[B]

 

Sorry Cdelena but there is a restriction by definition. However, it may not be a detriment from a system design viewpoint.

Thanks to mingster for the data. The data confirms Cdelena's point that it is well designed.

 

Here's some hard data on why you don't want to replace the aitbox top with a mesh version:

[QUOTE]Originally posted by jeff:
[B]First, I drove around on a 25mile loop, with about 15 miles of interstate to get the car fully warmed up. The ambient temp outside was