k&N cone filter

[viali8]

i have heard some mixed opinions about the K&N cone filter. Does it really do anything for the car? i heard it is not good (counter productive) in stop and go traffic. i also heard that i might feel a difference on the high way. Any noticable sound difference? sorry for the noob questions. just trying to gather as much info. as possible. thanks Matt

[Garageaholic]

If you make a heat shield, which isolates the filter from the rest of the engine compartment, that may help. bc otherwise you'd be sucking hot air ... and that's counterproductive

Other than that, use the search function. I'm sure there's alot on this subject....

[PeaveyBassist]

Sound difference only. Louder intake sound. (which sounds awesome if you ask me btw)

Will

[RCWells]

Not to argue with Will here, but honestly, mine (and it's for the M30 AFM which is larger than the M20 AFM of course and therefore should be sucking even MORE air) does NOT create much more intake noise, at least not very noticeable from inside the car. I thought it would, and was a bit disappointed, but it just didn't.

I've yet to install a heat shield, but it's coming eventually even though I question it's effectiveness/usefullness.

The way I see it, and I don't know how it would be proven, unless on dyno (I've never seen figures from such), at idle, just sitting at a red light or stop sign for example, yes, it would be sucking hot air. However, once underway, moving down the road, air flow would have to push out the hot air from underhood, so I don't see how it would be sucking hot air then.

If someone wants to explain, I'm open to education here.

[PeaveyBassist]

Bobby, do you have stock exhaust or some aftermarket catback one? I havent had a cone filter but I have had my intake box drilled which would basically be the same effect and I noticed the intake sound a lot.

Will

[RCWells]

Stock exhaust. You know what's really wierd? When I drilled my box on the black car, it DID make a big sound improvement (it had a stock exhaust too), but when I drilled the box on this car, it didn't. ??? but true.

[PeaveyBassist]

Veeeiiiiirrrrrrrddddd

Will

[E30/M30]

The way I see it, and I don't know how it would be proven, unless on dyno (I've never seen figures from such), at idle, just sitting at a red light or stop sign for example, yes, it would be sucking hot air. However, once underway, moving down the road, air flow would have to push out the hot air from underhood, so I don't see how it would be sucking hot air then.

If someone wants to explain, I'm open to education here.

Your are right, some one with a stand alone ECU data logged a couple of trips, one with a cone filter and one with the stock air box, i think he said the data from the IAT said that the cone filter was a little warmer when driving along but not by much.(depending on the placement of the filter)

A cone filter will suck hot air in when the car is stopped but generally with a halve decent engine traction in first gear from a standing start will be the bigger loss performance wise than the higher intake temps costing 5-10bhp(?) ?