Which one is likely to give a more stable power increase?

I've heard rumours of cone filters drawing in warm air from the engine bay, whereas the panel filters are supposed to avoid this due to the airflow going straight into the airbox.

I've had a K&N cone filter and it made a difference, but at the same time when the engine was hot it seemed to tail off possibly due to the warm air being drawn in.

I've gone back to the standard airbox at the mo due to fault finding trying to eliminate things one by one, and I've sold the K&N, so its a lot slower with a standard air filter!!!!

Ta

Stick with the standard air box and get a good panel filter, best imo.

I've got the green one and it seems fine.

Cheers

A lot slower? Probably a placebo effect. It'll work against the engine. Standard paper here renewed as per maufacturers suggestions.

Recently had K&N panel filter fitted by Awesome with Major Service and Cambelt change it seems to drive really good now.

The service probably helped too...

I know but seems smoother!

only go for a cone if your going to provide a source of cold air to it from some pipe work comming up from outside and try and sheild it from the engine. as the engine will make the under bonet area very hot and thus reduce amount of cool (more dense air entering the engine). and the lower down the scoop the better as the lower down the cooler the air (but more likely to pickup water.)

Interesting reading here:

Browser Warning

Great writing, but complete rubbish. Factory airboxes are designed as much to silence the intake as to flow air.

It's going back to before there really was an interweb, but the late lamented Cars and Car Conversions magazine's Gerard Saurer did a comparitive test of standard paper element, wire gauze, K&N, and Pipercross foam filters for a specific application, using a proper manometer flowbench, rather than a 52mm gauge.

His results were that the K&N had a slight edge using brand new filters, but double the flow rate that the paper element could manage after 5_000 miles.

thing that concerns me is how much the paper element catches compared to a foam filter is the paper one is significantly blocked after 5k when a foam one isnt.

It's not got the same scientific validity and repeatability, but there have been tests done with the "dump a specified dust into an intake plenum, and see how much gets through" technique. Paper, foam and cotton gauze tend to come out roughly equally on mass of dust caught, but the paper filter loses badly on a depression test after the dust test. Again, I'm going by memory from when K&N and Pipercross were pretty new to the UK market.

If K&Ns didn't filter dust, would Baja racers use them?

must agree that the foam filters seem to last longer and generally perform better than the paper elements.