Rep Power: 527

I think I'm correct in assuming that one factor in how well an intake performs is how much air it allows in. But to what extent does this work?

Say for instance that the stock intake allows in a volume of air we'll call "x."

If it were possible to design an intake that brought in x^2 (x squared) air, how much would that benefit the engine?

I also assume that there's a limit to how much air a given engine can use. What happens if you bring an amount of air that's higher than what the engine can use?

Thanks.

IronFist

 
Rep Power: 423

You can only stuff the cylinders with as much air as they'll hold. What ever air doesn't get in, just stays in the pipe. Even now, the intakes are flowing more than the engine can ingest in one breath. Me and a friend figured this out, but I can't remember the exact numbers. The engine can handle about 210 CFM (throttle wide open) of air, and the Cold air intakes can suck up about 400. So you're already not using all the air. The only way to get the engine to use more than that is to force it in (i.e., Turbocharge or supercharge it).

 
Rep Power: 315

For the engine to benefit from more air, it also needs more gas to burn.

Aftermarket intakes are less restrictive, therefore the ECU can compensate for more air by injecting more fuel. When you want to go air^2, the car will run lean without added gas.

 
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An intake doesn't just suck up 400cfm of air by itself. Air is sucked through the intake because of vacuum, the only way to surpass the amount of air flow created by vacuum is to force it in as boiler had stated turbo/supercharged(nitrous, but that's not forced, it's sucked in and then expands(dry kit)). So basicaly you can have an intake that will easily flow 1000 cfm but will only suck what the engine needs. If your at WOT sucking in as much air as possible, when you shift your throttle plate will close and the air will be hitting "a brick wall" which will reflect it back down the intake tube (to an extent) but when you punch the throttle again, it will just be sucked back in. Hope that explains what you wanted to know. good luck

 
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That pretty well sums it up. The ECU on a 7th gen will only allow a limited amoung of extra fuel, so more air than to retain the fuel/air mix isn't going to be introduced. That and limited timing advance is also going to put a cap on the amount of air your engine can use.

 
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Well then it would be necessary to change out the fuel-rail and fuel regulator, and install bigger injector to handle the extra flow.
And you can get another ecu, if that is the only barrier aside from those upgrades.

 
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All an intake does is remove restriction, if there is any. Question is rather the oe intake is restricting the motor from taking in the max amt of air possible - NA. IMO, the oe intake is very good and that's why you can make out an intake type sound in the mid-upper rpms. Hondas in the past have had much more restrictive intakes, especially on the accords where noise is of great concern.

You need more fuel with the air but I don't think the ecu is the problem. I just don't think the oe design is really offering much restriction.

 
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good enough for me... that and everytime i click on this thread i get lost on that x^2 thing....