Flashwing

Where is the proof of this? Has anyone taken readings of intake vacuum at WOT?

Use whatever filter you would like but the fact remains that the intake system was well designed and there are very little gains to be had from there.

Here's the exit question: Which end of the system is restricted due to federal law? Answer that question and you'll discover where the true source of restriction is.

olddragger

iTrader: (3)

Misunderstood. I wasnt referring to our car--just in general as the topic suggests. Paper versus K&N.
However it is safe to say that where ever there is corrugation in a pipe--there is restriction. Now how much versus what our engine needs in its NA form--I dont know. FI does change things though.
If you run the oem corrugated rubber pipe in an FI system-then I would bet you have some restriction going on.
It would be interesting for someone to do some vacuum readings---you are right.
OD

9krpmrx8

iTrader: (46)

It's funny because I was watching Horsepower this morning and they added a Magnacharger SC and a ton of other mods making it put down over 500WHP and yet the factory air box and paper filter remained.

Flashwing

Ok understood. I won't get in the middle of a factory vs. aftermarket filter. I put that in the same category as oil filters. Even thought there might be objective information out there (which I used to decide which type/brand to use) there will still be examples where one or the other caused a failure.

I would be curious about the overall surface area that many of those cars have with their filter elements.

ASH8

Yes you will get HP gains from using this type of Air Filter or that type...you will get even more gains running with no Air Filter at all, but how long will any Engine last with no filter?..

K&N may give you 1 HP gain, this is only because it is letting in more Air...so more air will mean less is being filtered....less filtration means....pretty simple really.

olddragger

iTrader: (3)

yep cost versus benefit on just about any modification. Agreed. I think a K&n filter can be used in the right situation.
Actually I think people need to talk about what flow rate they need first--then go from there?

9krpmrx8

iTrader: (46)

From the looks of it, it was smaller than the RX-8's stock filter.