REV2RED - I too really liked the sound of the car with the airbox lid off, however I was very awar of the loss of throttle response and power.

The solution - a CAI - I went for the PRM as it was a 'no cut' install. (do a search - there are several good threads detailing this and other CAI's)
www.prmracing.com
I am really pleased with it - great noise, no loss of throttle response and possibly (but dyno ) a small increase in power from ~7000rpm upwards (remember, increasing stock power was not my motivation here - mearly retaining it!)

 

i raced another s2000 withmy airbox out and i lost 1.5-2 cars lenth!!!
so yes it does lose power!

 

This is a scientific assessment if I've ever read one. Seriously though, care to share with us the mod list of each car, the weight of the drivers and/or passengers, the amount of gas in each car, the model year, the parameters of the race (from a stop, from a roll, etc). Unless we know such information, how would your comment add to the discourse? Who did you race and what is the distance you usually lose by? Completing a mod that at best, might make 2hp at speed, and gauging it's effectiveness based on racing another car is about as unscientific a way to verify something as possible. Most folks, if not all, could not sense a .2 difference in a 1/4-mile race but at the trap speeds normal for the S2000, .2 seconds is nearly two car lengths. Please understand this isn't personal but personal observations regarding mods which make 1-2hp don't mean diddly squat if one isn't backing it up with either accelerometer or some other method which is a helluva lot more calibrated than one's butt dyno. Run your car with two bars of gas and run it again on a full tank and then attempt to estimate how the difference would affect your 1/4-mile time. See what I mean? I still haven't read anyone's assessment on why they think at 100mph, an airbox cover with the lid and baffles intact would make for better breathing than with the lid off and the baffles removed.
I said it already. Down low, the heat soak from lid removal reduces your performance. Up high, without the lid on, the performance is marginally better. The two results cancel each other out and running 1320's with/without the lid on will back this up. Your final times aren't going to change significantly with or without the lid on but your 60-foot time might change due to the heat soak however once the car hits 60mph, the increased air flow going over the filter will help to make up the loss you encountered from the start. In the end, at the line, the timeslips aren't going to be dramatically different so if one races from rolls or stop signs, keep the lid on but if you like the sound and don't spend much time street racing, you're not creating a 220hp S2000 with the lid off.
In the end, butt dyno observations add little to the actual truth, though they make for interesting reading.

 

well then it s comming back off...

 

Leave it on.

 

Hum.... I wonder if taking out the faux side-intakes does anything to help performance at all?

I'm talking about:
http://www.grille-tech.com/detail.html?prodid=40

Would this create more airflow within the engine bay and help cool things? Anyone got this mod?

 

as what i have read on this site it does not make any difference. So dont cut it out.

 

It depends on whether or not you intend to use that area for snaking an intake tube
or flex hose through the wheel well and into your filter housing. It DOES make a difference in that regard. It wouldn't make any difference if you're using the stock intake or an intake where the filter is not attached to a hose which is directing air
into it.

 

Hmm.... what oil temperature do you guys get with stock (or modded) air filter/intake?

I get up to about 110 degrees centigrade maximum... but I've got the ARC air intake.

 

wouldnt taking the lid off effectively turn our intake into a short ram? kinda???