Drop in filter VS CAI

[Apex Motorsports]

Originally Posted by 1Canuck

having trouble understanding this. would not the surface area of a filter be the limiting/restriction for flow. does the cone filter have more surface area than the flat stock? it does not appear to. the cone filter material is same/similar as the replacement flat filters. that is where I have trouble seeing a different flow rate if both are used with the same other components.

That was my point, cone filters have significantly more surface area than a panel filter thus immediately increasing the amount of air flow available. When I get a chance I will snap a side-by-side photo.

[Dark_Horse]

The difference between the cone filters and the stock flat one is that the stock flat pulls air only from one side. The cone filter pulls air from all sides so it's essentially multiplying the amount of air the engine is taking in by almost double. Performance replacement stock filters help by increasing air flow but a cone filter is ideal because it pulls air from all the way around itself, not just from one side.

[tazman]

Originally Posted by Apex Motorsports

The gains from the scoop really come on just before 3000RPM and climb from there. Driving around town you are not going to notice it but when you jump on the throttle you will.

I thought the gains would have been more at higher sppeds from the supply of cooler air. I was concerned there would be no advantage at the lower speeds when you are not getting the extra cool air pushed into the area.

[Dark_Horse]

I would think it would be more of an rpm based effect. After all your engine acts more like a vacuum that sucks air in and then pushes it out in the form of exhaust. The more air you can push to it with little to no restriction the better it is. That's why forced induction works much better at higher rpms. It forces more air in than the engine would normally be able to draw in on it's own creating a boosted air flow.

[Apex Motorsports]

Originally Posted by tazman

I thought the gains would have been more at higher sppeds from the supply of cooler air. I was concerned there would be no advantage at the lower speeds when you are not getting the extra cool air pushed into the area.

Originally Posted by Dark_Horse

I would think it would be more of an rpm based effect. After all your engine acts more like a vacuum that sucks air in and then pushes it out in the form of exhaust. The more air you can push to it with little to no restriction the better it is. That's why forced induction works much better at higher rpms. It forces more air in than the engine would normally be able to draw in on it's own creating a boosted air flow.

It is both. The scoop will actually show about +5 rwhp on the dyno sitting still with no air flow across the car. Like Dark_Horse mentioned, your engine literally sucks in air and when it is sitting on a dyno that gain is 100% attributable to the scoop simply opening up a much larger channel for fresh air to get to the air box than it has otherwise. The engine can simply inhale better. On the street your forward movement is definitely forcing a lot of cool air thru the scoop and into the air box even at relatively slow speeds. Not only in the engine able to breathe better but it is also getting a "ram air" effect. This does not continue on endlessly though. You reach a point/speed where the "ram air" effect reaches maximum efficiency. The filter again becomes the weak link because more air is being forced into the air box than it can handle.

[1Canuck]

OK, so I went out and got the K&N replacement flat filter. dropped it in and hit the highway. acceleration felt stronger and indeed looking at the speedometer this was confirmed with a rapid rise to illegal levels. Of course seat of the pants dyno means nothing to others, but I like it and have saved $400 Canadian in the process. I cannot imagine what the CAI kit would produce in comparison, but I already have what conditions locally can handle.

[tazman]

Thanks for the info I will keep all this in mind when I am ready to take that step.