Small K&N cone filters: How well do they flow?

[RealMcCoy]

I've got this car at the shop that I'm trying to clean up and make right... It's been worked on by too many people too many times.

What's the consensus on the above filters? They're hooked to some mid sized t3/t4 style Comp turbos, with a goal of around 600AWHP. I've never run them before, but they just don't look up to the task to me...

[Chris@Rvengeperformance]

I have no scientific basis, but I did always wonder why people put the tiny filters on when the cylindrical ones will still fit. I always try to put the biggest filter on that will physically fit. Really I just don't like the look of the tapered ones either.

[NOMIEZVR4]

If you get a set of replacement filters that still fit the intake pipes, please post up. I'm also interested in larger filters. I've got the same ones.

How do you feel about those filters feeding evoIII 16g's, still too small?

[RealMcCoy]

I have no scientific basis, but I did always wonder why people put the tiny filters on when the cylindrical ones will still fit. I always try to put the biggest filter on that will physically fit. Really I just don't like the look of the tapered ones either.

That was pretty much what I thought the first time I opened the hood... In fact I asked him: You want to make how much power through those motorcycle filters?

If you get a set of replacement filters that still fit the intake pipes, please post up. I'm also interested in larger filters. I've got the same ones.

How do you feel about those filters feeding evoIII 16g's, still too small?

I would think we'd be talking about similar power numbers to this car... The turbos are only 47mm inducer, so an evo III is slightly larger, but the spool up on the DBB Comps is pretty amazing.

I'll post up what I come up with... I'm pretty sure it isn't leaving with those filters on it.

[sergechronos]

Just some food for thought from me,which may or may not be right, however I would assume that the piping would be your limiting factor, not the filter.

If we assume 2" inlet piping, regardless of the size of the filter (either in surface area or volume) the inner diameter of the pipe should still be a bigger factor. A cone is going to have less surface area and less volume than a plain round cylinder filter for sure, however without knowing the CFM capabilities for the filters it makes no difference. So long as there is sufficient surface area to filter enough air to meet demand, the rest is irrelevant. That said, there isn't a ton of information available (even from K&N) on what the filters ratings are. Best bet would likely be to try it as is, then swap on bigger filters and see if it makes a difference, or try to email and get information from manufacturers. E3 16Gs are what, 500-600CFM turbos?

[KeithMac]

My car happily runs 30 psi using filters over the turbo intakes that are slightly smaller than that.

You will be fine using those.

[donniekak]

Filter Selection

[RealMcCoy]

Filter Selection

Hmm.. Measuring them out, and using that guys numbers, they have 118 square inches of surface each, and would flow 717 CFM each....

[NOMIEZVR4]

Hmm.. Measuring them out, and using that guys numbers, they have 118 square inches of surface each, and would flow 717 CFM each....

So if e3's are 600cfm turbos each then these filters should be sufficient according to the math?

[RealMcCoy]

Just pulling numbers out of thin air, let's say you needed 850bhp to get to your goal of over 600 at the wheels... Most of the airflow calculators are going to tell you you need over 1000 cfm to accomplish that. Even at 550 each, the numbers would seem to support these filter's ability to do the job.

Of course that has little bearing on service interval... The smaller the filter, the more often it will require cleaning to maintain that airflow, where a larger filter will have enough flow even half plugged.