Road Rage

Silencers are always viewed as power robbers, but it is like most Web "knowledge": only partly true - a silencer can not only reduce irritating intake roar, but can actually increase midrange torque. The intake system can be tuned to a resonance point that optimizes flow, just like aligning the pulses in the exhaust system can optimize flow. The relevant physical principle is that of Helmholtz resonance (quo vide) for the engineering oriented.

An engineer from Volvo, for example, submitted a paper at an SAE convention several years ago, where he showed the loss of midrange torque when a "performance intake" was fitted to a hi-po Volvo turbo "S" model. Peak HP went up a few ponies, at the expense of midrange torque - I say that is a poor tradeoff unbless you keep the car at or above 6k RPM all the time.

HI SPEEDR

Sorry guys, I'm from the old school. Honda designed and engineered the box that way for a reason. Why question it?

JL9000

[QUOTE]Originally posted by HI SPEEDR
[B]Sorry guys, I'm from the old school.

fastpace

i did that EXACT THING to my friends s2k, there was actually a whisle sound that kept happening. Luckly we did this as an experament b/c his AEM CAI came in the same day....
It really doesn't do much of anything, go get yourself a CAI, the car sounds really nice afterwards, i love it when i mash down the throttle and the car just sounds totally pissed!!!!!

dolebludger

To my knowlege, there has been no change in the stock air box from day one. All have the divider with the tunnel from the front intake going through it to the top of the filter. There has been a lot of discussion and controversy about the s2k air intake, and options for making it better, and we all have our opinions. My opinion is that it is the only poorly engineered thing on the car, as it sucks in hot air right above the radiator, and cool air from the grill is blocked off by the baffle. I compare this to the air intakes on my wife's MB C320, which isn't even a performance car, to prove my point. The MB has twin TBs, one for each bank, with intake horns running straight to the grill with no radiator heat problem involved.

Solutions? There are many suggested, but here are mine. Make and install a Radmat to insulate away some of the radiator heat, as suggested by xviper. Buy an additional stock airbox, so the car can be quickly converted to stock for resale. Remove the divider from that airbox by "scoring" it with a sharp knife and tapping it out with a rubber hammer. Raise the point where the filter prong goes into the bottom of the box by about 1" so the filter isn't sitting with its bottom blocked. Shim out the baffle between grill top and radiator brace, right below the stock intake, as far as you can and still close the hood (about 1") to get some fresh air to the stock intake. Finally, cut a 3 1/8" diameter hole in the passenger side of the airbox and run a flexible aluminum 3" round bendable duct from the airbox to the hole in the passenger side of the fender cavity in front of the wheel well. Even without cutting out the fake side airvent in the bumper, a good amount of fresh air gets into this cavity when the car is moving. And oh, yeah, get a K&N or other low restriction filter element.

Results? I did this to mine, and "butt dyno" is about all you can use, as much of the "mod" depends on the car moving through the air. No additional noise at all. Better low rpm throttle response, and no dead spot at 5K or anywhere else. Smoother transition into VTEC. Very cheap costs, and almost instant convertability to stock. And better gas mileage.

Thanks,
Richard

Russ

After I dremeled away my stock air box (about two days into ownership), my subsequent accelerometer runs revealed an increase of 2.7hp. At that point, my intake tinkering life began. IOW, the intake design has SOUND CONTROL as its main priority, not performance. Hell, even with a sportscar designed from the floor up, they compromised for the masses. It is a functional intake, but not one which maximizes performance, just like the OEM exhaust.

dolebludger

Russ:

The odd thing is that my tinkering described just above didn't increase noise level at all. All it did was to reflect the effects of more than doubling the square inches cross section of air intake area, cooling down and making more accessible intake air, and, and increasing the efficiency of the filter itself by getting its "belly" off the bottom of the box. Now I'm no degreed automotive designer or anything like that, but I think a grade school child could look at the s2k stock air intake system, compared to that on the MB C320, and tell us some of what's wrong with the s2k's, if they were given the info that the purpose was to take in the max cool air possible!

Thanks,
Richard

gixxsu

[QUOTE]Originally posted by JL9000
[B]
There are always compromises from a factory car.

The air-box is well-designed to eliminate noise, and that *may* compromise the actual performance.

Bassem

if it makes a difference, spoon runs their racecar with thier snorkel and with their box gutted.

bassem

dolebludger

If you leave the "L" shaped airpath that is created in the top of the stock box as is, I can't see where removing the divider would do anything. But, as I recall, the Spoon set-up calls for removing the stock airpath, and using ram air principles to get air into the whole box, so the filter can use it. If this is true, "gutting the box" (including the divider and the "L" shaped airpath) would be the only way to get the full effect of the Spoon.

Thanks,
Richard:) :) :)