K&N Air Filter

[Guest]

Anybody using a K&N Air Filter on their 997?

If so, have you noticed any differences in Performance / Economy / Sound...

Cheers

Dave

 

[burrow01]

Or likelyhood of being able to claim on the warranty []

Pete

 

[Guest]

Pete,

The OPC will fit the K&N filter for you. It's just a basic replacement air filter, not a complete induction system...

Moster Boxster owners swap their air filters for the K&N equivalent. Gives about 8 to 10 extra bhp on a Boxster S for just £30

Just checked the K&N website, and this is the product that 997 & 996 owners need...

http://www.knfilters.com/search/product.aspx?Prod=33-2786

Dave

 

[burrow01]

Hi,

I thought OPC's would only fit genuine Porsche parts? also I would be suspicious of an 8-10Bhp increase just from an air filter, if it were that easy to up the power, Porsche themselves would do it []

Pete

 

[Rodney Naghar]

I've heard the K&N actually reduces BHP as it sucks in warmer air..and that the standard filter is pretty good....the K&N is supposed to improve induction noise tho.

 

[Guest]

It definitely made an improvement to the performance of my Boxster S and brought the best out of the Sports Exhaust too (I was looking for tunnels and bridges all the time)

8 to 10 bhp only represents a 4% increase which I'm told is fairly average for a Sports Air Filter

 

[Dave Wilkinson]

I just caught sight of this thread and am constantly amazed at the generation and belief of these "Old Wives Tales" which spread on subjects like this.

How, pray, would an air filter have any impact on the temperature of the air coming into an engine?? Given that a 3.2 litre engine at, say, 4000rpm, is sucking in 2000 x 3.2 = 6,400 litres of air every minute how long do you imagine it hangs around to get heated??

Why do Porsche not fit a K&N filter as standard?? Why would they spend, say £25-30 on an air filter when the corrugated paper variety works well and costs them 50p??? Now let me see????

Is 8-10 bhp believable?? Maybe, maybe not. The K&N is designed to give the airflow a freer induction path. If the freer path allows the air to move slightly quicker, without restriction, the fuel is likely to be vapourised more efficiently and therefore burn more efficiently. Plus it lasts the life of the car.

All in all I reckon it's a "no brainer" as our friends across the water would say. OK - rant over.

Regards

Dave

 

[burrow01]

ORIGINAL: Computamedic

Why do Porsche not fit a K&N filter as standard?? Why would they spend, say £25-30 on an air filter when the corrugated paper variety works well and costs them 50p??? Now let me see????

If they could get an extra 8-10BHP out of the engine for a £25-30 cost, why would they not do it - they could charge an extra £1000 for the car to cover it []

Pete

 

[Dave Wilkinson]

Pete,

All car manufacturers spend a huge part of their budget trying to reduce the build price of the car - what they don't need is a way to increase the build price. Bear in mind that a good 80% of buyers - Porsche models included - don't know what an air filter is, much less pay £1000 extra for the privilige of having one they don't have to change.

Having worked for Ford Motor Co. some years ago, I've seen Suggestion Schemes get maximum awards for leaving something off a car which costs literally pence!!! If you multiply the cost of a K&N filter - even to Porsche - by the number of Boxsters/Caymans/997s/Cayennes produced every year and then try and sell the idea to the accountants I suspect you will come away with your tail between your legs!! Not every purchaser is an enthusiast - a fact which the manufacturer has to keep in mind.

The fact is that they could get an extra 8 - 10 bhp out of the engine for free by changing the DME mapping, but they don't. The specification is decided by what the marketing department feels the market needs, not what the engineers can achieve.

Regards

Dave

 

[Guest]

I thought OPC's would only fit genuine Porsche parts?

Most OPCs will fit yoour K&N air filter free of charge.

 

[burrow01]

Fair enough, I understand the cost factors in mass production, but I still don't believe that a simple air filter will give you an 8-10Bhp increase. Power increases are possible via changed mapping, but I believe other factors restrict this - reliability, worldwide standardisation (engine must meet emisions standards in all countries, and work at all altitudes) When your engine is remapped, all you are really doing is accepting a lower safety margin, which is proably acceptable if you are only going to drive the car in Europe, on good fuel etc

Are there any dyno readouts with before and after comparisons for K&N filters? the filter is easy to change, so these should be readily available.

My engine is already producing 287Bhp, so maybe there is another 8-10 easily available []

Pete

 

[Dave Wilkinson]

ORIGINAL: burrow01

........but I still don't believe that a simple air filter will give you an 8-10Bhp increase.

Pete

I'm not sure I do either. I could be convinced that it shouldn't reduce the power but I think an 8-10bhp increase might be a bit ambitious. It does sound nicer though!!!

Regards

Dave

 

[Guest]

I've been searching for the webpage where I read this (unsuccessfully), but K& N claim to offer between 2 and 4% increase in BHP for most normally aspirated cars.

The 8 to 10 BHP increase for the Boxster S should translate to a 10 to 12 BHP increase for the Carrera S

Of course, this is all theory and cannot be proven without dyno testing.

As I mentioned earlier, for best results the K&N should be completemented by the Sports Exhaust! []

 

[burrow01]

I would agree that it should sound nice, with a K&N plus PSE, but if you look at what is involved in the engine performance upgrade option for the 997 to give a 26Bhp increase ( this is all from memory, so I apologise if it is incorrect) it is substantial, new head, intakes, manifolds and remapping

this costs somewhere in the region of £8k?

Pete

 

[Guest]

Pete,

It's worth it for the sound alone. To be honest, you'd barely notice a 10bhp increase on a Carrera S apart from slightly improved mid-range acceleration

 

[Rodney Naghar]

How, pray, would an air filter have any impact on the temperature of the air coming into an engine?? Given that a 3.2 litre engine at, say, 4000rpm, is sucking in 2000 x 3.2 = 6,400 litres of air every minute how long do you imagine it hangs around to get heated??

This is true under normal conditions. However, because you are exposing the air filter directly to the hot environment near the engine now, and if the flow of air is markedly decreased or erratic (ie when driving slower, say less than 50mph, or stop start conditions) you will lose power.

Then you have cotton filter oil issues....does it lead to MAF malfunctions?

Then you have filter dust issues.....the cotton versions like K&N clog up with dirt much faster, and when very clean, let in a lot more dirt. So there is a fine region where you might get the performance boost and not letting in more dirt than standard paper versions.

I don't believe you can compare Ford's marketing ethos with Porsche's. Porsche cutomers are one of the most brand loyal and have a much lower price elasticity of demand.They are prepared to pay more than Ford customers for better performance, because, in part, that is one of the greatest selling factors of the brand.

If these filters really worked, and didn't require frequent cleaning, and didn't produce a higher induction noise (which won't suit most customers) then I believe Porsche would add them and charge the extra.

2c worth etc

 

[Elliot Davies]

it MAY also increase your insurance as it is classed as a performance part
cost me an extra £40 ins. when i declared mine on last 964 !

 

[Dave Wilkinson]

ORIGINAL: Rodney Naghar

This is true under normal conditions. However, because you are exposing the air filter directly to the hot environment near the engine now, and if the flow of air is markedly decreased or erratic (ie when driving slower, say less than 50mph, or stop start conditions) you will lose power.

Then you have cotton filter oil issues....does it lead to MAF malfunctions?

Then you have filter dust issues.....the cotton versions like K&N clog up with dirt much faster, and when very clean, let in a lot more dirt. So there is a fine region where you might get the performance boost and not letting in more dirt than standard paper versions.

I don't believe you can compare Ford's marketing ethos with Porsche's. Porsche cutomers are one of the most brand loyal and have a much lower price elasticity of demand.They are prepared to pay more than Ford customers for better performance, because, in part, that is one of the greatest selling factors of the brand.

If these filters really worked, and didn't require frequent cleaning, and didn't produce a higher induction noise (which won't suit most customers) then I believe Porsche would add them and charge the extra.

2c worth etc

Rodney,

I have no wish to start an argument but I would like to give a reaction to your comments above.

Firstly, whilst what you say about air volumes is theoretically correct I am intrigued how anybody would determine a loss of power - even if it were true - at 50mph?? Even a difference of 100bhp is unnoticeable until you put your foot down - at which point the air volume rises steeply and any potential problem instantly disappears.

I think K&N would argue strongly about the "letting more dirt in when clean" - it's simply not true.

If the K&N filter clogs up quicker, where does the extra dirt come from??? This is Old Wives Tales again!!! You always have the option to clean it at each service if you feel it necessary. If the filter is correctly cleaned AND correctly oiled there is no risk of MAF contamination although it IS a risk if the filter is over-oiled.

I think the comparison between Ford and Porsche is not as misplaced as you might think. Porsche isn't the most profitable car manufacturer in the World through throwing away potential profit on unneccesary expenses. You can't judge the market requirements based on the opinions of a small (enthusiastic) minority. Just look at the pathetic proportion of Porsche owners who even bother to join the Club!! The reason companies such as K&N even exist is only because of the unwillingness of the manufacturers to heed the small numbers of enthusiasts who want something different. Given that many sales of new Boxsters and 997s will be made through company car schemes I struggle to see the enthusiasm on the FD's face having realised they've paid an extra £1000 for 8bhp extra!!! Whether you would have the same reaction is for you to judge.

I think you answered your own question in the final paragraph. It's not for everyone - so why would Porsche choose to install it as standard???

Regards

Dave

 

[nsm3]

I put a K&N filter in my M3 after 5k miles and ran it to 28k. The advertising claimed 5bhp increase but I could never tell the difference to power or sound.