K&N filter

It's amazing how a bit of extra noise cons the brain.

You would think so wouldn't you but there's actually less noise. With the paper filter (which was new) there was a lot more air induction noise on open throttle.

I remain unconvinced about your claims.

It did nothing for Kermit's quarter mile time nor his fuel consumption, but it has more than paid for itself by now since it's washable and reusable.

Are you talking about a K&N kit or a replacement for the original filter?

Just the replacement filter. I'm a sceptical person by nature but read various other posts from people with a similar car (Daewoo Lanos 1.4) who were more than surprised at the difference in performance a K&N made. Now I don't know if this could be partly down to a bad design of the air intake system on these cars, but when pushing hard with the original paper filter you would get a loud roaring noise through the air intake system and little power increase. It sounded like it was struggling to suck in enough air. The airbox itself goes into the side wing behind the plastic splash guard and into another large box. I don't know if this is normal but I was surprised how small the hole is that sucks in the air and also that it points towards the rear of the car.

All I can say is that a K&N has definitely made a big difference in my case and well worth the £28. I drive the same roads & inclines and know exactly where I would previously have needed to change down a gear but now has much more pull and response to the throttle without the loud roar through the intake.

Righto, they're OK.

The air intake will have been designed to compromise in almost every area - noise, power, economy and emissions.

That's possible, yes. However, also make sure it doesn't upset the emissions, you wouldn't want to fail a road-side test!

The roar will probably be because of the restriction in the air flow with the OE filter, it will probably cause a harmonic resonance to build up under certain conditions. This is actually desireable to a small extent, as it can agitate the air flow and aid complete burning in the cylinders.

One thing is for certain, if a manufacturer could attain all their specifications using a K&N design of filter, they would have used it. There will be a loss somewhere, although probably nothing much.

For sure cost is a factor, but at the volumes of units sold to a manufacturer, it wouldn't make much, if any, difference there.

Hmm. How would you recognise this sound? :)

It's reasonably normal. But since you are using the same induction system, just a different air filter, it won't make much difference. The reason for this is because of the size of the air filter relative to the intake and the trunking. It's much bigger, right?

There _may_ be a difference because air can pass better through the filter, but it won't be significant.

Yes, but have you checked the data (say using an OBD-II Scanner* or similar), or had the car on a rolling road? With ours (yes, not the same engine of course) there's no statistically provable difference in throttle positions for various cruising speeds.

Unless you're using lots of throttle, the ECU won't enrich the air:fuel mixture and you'll still burn the same amount of petrol to produce the same amount of power to produce the same amount of torque...

I can make a bigger difference running higher tyre pressures.

If it's producing less noise (ours is quieter wearing the K & N replacement panel filter), you may be mistaken for believing that you're using less throttle.

"DervMan" wrote in news:EzMGe.15527$ snipped-for-privacy@newsfe3-gui.ntli.net:

I tried a K&N element once. It *seemed* faster at first, but I eventually accepted that it had made bugger all difference. Mind over matter, placebo effect, call it what you will, but I reckon that's what it's all about (IMHO).

Any performance increase must come from less resistance in the filter. This worries me a great deal. If you live in or near a large city, there will be a lot of dust in the air. My car is covered by a fine layer of dust just 24 hours after washing.

If you switch the Eastcoast power booster to the maximum-27bhp on the Citroen/Peugeot hdi engines, they stipulate the paper filter be replaced by a K&N. £38 but you never buy another filter. Wash in solvent every couple of years and spray the cotton element with light oil. (The extra performance is definitely not bollox). DaveK.

BANG ON!

K&N is a competion filter. It's just a bit better than a wire gauze. Wire gauze stops big stuff like small birds, bumble bees, stones and large grit geting in. Also prevents damage from other teams crews flicking nuts at you! The K&N stops finer muck than a gauze but really fine stuff eventually passes though.

That's what the oil is for...

Mind you, I find the K & N great for stopping puppies and small children from being sucked up into the engine. :)

The focus owners club took various induction kits for diesel and did some RR tests. The general conclusion was that a K&N gave maybe a 1 to 2% increase and that's probably within the equipment error anyway.

Correct, and in any event, you're not going to feel or see 2% on the road, not even if you're doing a traffic light shoot out against another car of the same type, heh.

You can achieve a greater difference through tyre pressures, ambient air temperature, or whatever.

Snow on the intercooler is always fun but it doesn't last....

Sodastream CO2 as well...