K & N air filter question

[petestubbs]

Can anyone advise me on upgrading my air filter to a K & N system, i.e. Which system fits our car etc?

I dont want to replace the cartridge in the black holder, I want to put on a complete replacement and remove the black dustbin altogether to get the extra power and the better sound!

Also would I need to replace the pipes as well (I have seen some cars with the new filter with coloured pipes running out of it)?

Any advice would be appreciated,

Pete.

[Sy V]

So your after a K&N cone filter - almost an induction system.

[theelanman]

this has been discussed before....and IIRC the conclusions were...

there is a std air filter from k&n which drops in the bin....
there is also an induction kit.....
it was decided that the induction variety lost you power due to the fact it sucked in hot air from the top of the engine bay rather than having free flowing cold air coming in from under your bumper straight into the 'bin'..

i was going to do this but after what people whod tried similar said..I just went for the drop in one

cheers
G

[abmunro]

Has nobody enclosed the induction kit.

Then utilised the pipework leading to the Dustbin

[Paul.P]

Has nobody enclosed the induction kit.

Then utilised the pipework leading to the Dustbin

I looked at doing this with the Hurricane unit the Elise boys we're raving about, but it was gonna work out pretty expensive & then wasn't sure if was gonna gain anything apart from looking pretty, so have left alone at the moment to see if others have a go.

[petestubbs]

Thanks very much for that info,

If it is going to lose me power I will avoid it and save myself the expense!

So that is a great help.

A quick question about the one that drops in the bin though, does it give better performance?
Or more to the point does it sound better than the standard filter?

Thanks again,

Pete.

[ailwyn]

Or more to the point does it sound better than the standard filter?

Who cares, if you can hear the air coming in then your driving like an old woman anyway

[rip]

Or more to the point does it sound better than the standard filter?

Who cares, if you can hear the air coming in then your driving like an old woman anyway

[Enright]

A quick question about the one that drops in the bin though, does it give better performance?
Or more to the point does it sound better than the standard filter?

Good question.
ESM reckons not. In fact I recall him saying that K&N's allow bigger dust particles through, which are more likely to damage your engine long term.
But who knows how big the effects will be, and how long term?
It's almost impossible to quantify whether this would mean that a 200,000 mile engine rebuild was shortened to 190 or even 150 because of it.
He has also questioned the merits of big exhausts too.
These give a lot of increased performance because the turbo tends to creep towards overboost, but before you hit fuel cut-off it goes like a train!
However, once you have ported the wastegate the ECU should be able to control things properly again.
And that's the point - the ECU (and therefore his chip) has a pre-designed boost profile, so in theory the performance should be no different.
Despite this, lots of people have gone down the filter and big exhaust route anyway to increase airflow through the system - including myself.

I noticed more induction noise (which I liked) when I dropped a K&N in.
But I also noticed the wastegate chatter/impeller blade stalling noise much more, which I found a bit disconcerting, especially when I found out what it was and what it could be doing to the life of the turbo.
So I fitted a Bailey re-circulating dump valve and it cured it.
Now that I've got a 2 1/4" exhaust on with a "minimalist" silencer, I can't hear the what goes in at the front because of what comes out the back anyway!

Just a few pros and cons so that you know what you're getting yourself into (and potentially confuse you even more)!

[max and andy]

Ive been reading the forums,on K.N open filters.The forums seem to suggest that there are problems with them taking in hot air.And that closed filters are now thought to be a better way to go.I was also reading the Upgrades section at the top of the index page.This says that in Summer and when the engine is running hot.The filter and pipe and the area around the filter,felt cold to the touch.Which is now thought to be the best choice ?Open or closed. Max&Andy

[MattDon]

what i did was to fit a pipercross viper induction kit and plumb it into the current piping, with a little fiddleing i got it to fit plus i now have an easy way to plumb in the recurculating dumpvalve when it arrives. cant say if its given any extra power but it has freed up some space under the bonnet and looks alot better than the trash can. The only bit im not 100% on the the sensor thingys (where the two small hoses joint into the turbo inlet), id like to tidy that up but im not sure how, as a botch i cut a small hole in the silicone hose and stuck the fitting from the trash can in.

[surfboardfiller]

There is a lot of myth and Bullsh_t floating about regarding filters. Most of the negative things you read are based on assuption.

Paper filters are cheap and have an uneven filter structure, which is not as efficient compared to the surface area they have. The gaps between fibres vary in size which does not help air flow. So A paper filter will let in a certain size particle but will have a low flow speed. A mesh filter has evenly spaced gaps so can let in the same size particle but more air flow for its surface area. Mesh filter: like a seive, paper filter: like a dirty seive. So a mesh filter does not have to let in bigger particles, to have a higher flow rate.

If you have an open filter, you can build an air dam between the filter and the engine bay. See the pic in SyV's post, Just box the filter in with a gap to let the air in form out side the car. This stops warm (less dense) air entering the filter. The Hurricane on my Elise had a dam, and it was very loud!

[ektrolleyboy]

I like Sy V's photo' above. And on normal cars it is said to increase horse power by having an induction system.
No-one here seems to be able to answer absolutely whether an induction system on our cars is not a good idea. But it has been branded around.

I'm fitting my dump valve on the 6th and was wondering about an induction system upgrade at the same time... Confused!
And do the Magnecor leads free any more horse power would any say?

[tweetdriver63]

Ive been reading the forums,on K.N open filters.The forums seem to suggest that there are problems with them taking in hot air.And that closed filters are now thought to be a better way to go.I was also reading the Upgrades section at the top of the index page.This says that in Summer and when the engine is running hot.The filter and pipe and the area around the filter,felt cold to the touch.Which is now thought to be the best choice ?Open or closed. Max&Andy

There's a thread on here somewhere where somebody took temperature readings in the engine compartment. The results showed that the area where the filter is (open or not) isn't significantly hot compared to the ambient air. The hotest area is behind the engine/plenum. Presumably there would also be some cooling from air coming in through the duct from the wheel arch, which goes into the trashcan. (Perhaps somebody can provide a link to that thread??) If you find the thread about putting vents in the hood/bonnet, you'll find a link there.

Based on that little study, I don't think an open filter would cause a problem due to warmer air being drawn in. Additionally, if it allows more air to be drawn in, that would balance any detrimental effect of the air being a little warmer.

[ektrolleyboy]

Ooh... Look what I've just found.

A K&N Apollo. It a cone filter in a sort of airbox-ish sleave is the best way I could describe it. Isolating the cone from engine heat and still giving the benefits of a cone!

I want one!

[F1 LOTUS]

Temps -I monitored engine bay temps and found the air around the trash can to be reasonably close to ambient.
Noise - Turbo whistle and 'fluttering' sounds were more noticeable.
Filtering - LGM either had her oil, a friends or, read about someone who had their oil analysed (I believe oil co's do this FOC?) after running a K&N, and found evidence of particles suggesting inefficient air filtration?
In my experience F1 teams used to favour foam type filters - the best trade-off between weight, pressure drop [lack of] and filtration - probably in that order

[ektrolleyboy]

Hmmm. So we're no nearer an answer of what's best.

Who's gonna solve this mystery?

[F1 LOTUS]

This may help - air filter test.
http://www.bobistheoilguy.com/index.php ... &Itemid=66

Perhaps a group oil test could be arranged / negotiated - here's what it's about: -
http://www.bobistheoilguy.com/index.php ... &Itemid=56

[rip]

Does intake air temperature matter too much with a turbocharged/intercooled engine? All air will be heated when it flows through the turbo or wastegate, then cooled again by the chargecooler.
May be an awkward test to perform. By the time the air filter had been changed, ambirnt temperature would likely to have changed too, which would screw up the results of any such test.

[surfboardfiller]

Does intake air temperature matter too much with a turbocharged/intercooled engine? All air will be heated when it flows through the turbo or wastegate, then cooled again by the chargecooler.
May be an awkward test to perform. By the time the air filter had been changed, ambirnt temperature would likely to have changed too, which would screw up the results of any such test.

Hot air contains less oxygen as it's less dense. The hotter the air the less oxygen. Cool air is best. No point in doing half the job. just put a simple heat shield in and lag the pipes that get hot.
Put hot air in a cooler and it will be warm, put cool air in a cooler and it will be cold....


A temperature sensor in the inlet manifold pipe would give you the info you need. Maybe an O2 sensor?