Air filters

[flybobbie]

I have had fitted this last two years or so a K&N filter on my car.
I thought it made a difference.

Recently thought i would go back and try a paper filter (Bosch).

Only drove home last night and did some shopping, the car seems a bit flat now.
I think i will refit the K&N. I just wash it in petrol then use a petrol oil mixture to reoil.
Too much much oil clogs the filter up and it needs rewashing every six months. And i clean the air mass sensor.

The problem could be the paper filter has to many folds and is quite deep. Thus offering a lot more air restriction than the K&N.
More surface area, which ok if it was a flat sheet, but folded, it's offering a huge restriction to flow.
The k&N is shallower, by at least half and has probably one third the number of folds.

 

[baconJazz]

I have had fitted this last two years or so a K&N filter on my car.
I thought it made a difference.

Recently thought i would go back and try a paper filter (Bosch).

Only drove home last night and did some shopping, the car seems a bit flat now.
I think i will refit the K&N. I just wash it in petrol then use a petrol oil mixture to reoil.
Too much much oil clogs the filter up and it needs rewashing every six months.

The problem could be the paper filter has to many folds and is quite deep. Thus offering a lot more air restriction than the K&N.
More surface area, which ok if it was a flat sheet, but folded, it's offering a huge restriction to flow.
The k&N is shallower, by at least half and has probably one third the number of folds.

I have had fitted this last two years or so a K&N filter on my car.
I thought it made a difference.

Recently thought i would go back and try a paper filter (Bosch).

Only drove home last night and did some shopping, the car seems a bit flat now.
I think i will refit the K&N. I just wash it in petrol then use a petrol oil mixture to reoil.
Too much much oil clogs the filter up and it needs rewashing every six months.

The problem could be the paper filter has to many folds and is quite deep. Thus offering a lot more air restriction than the K&N.
More surface area, which ok if it was a flat sheet, but folded, it's offering a huge restriction to flow.
The k&N is shallower, by at least half and has probably one third the number of folds.

I just removed my K&N panel filter from my e86. (Actually on Ebay with cleaner kit at the moment) . I replaced it with a Mann (paper) air filter Which not only sounds better but the engine is definitely breathing better too. The reason for this is because I took the MAF out to have a look and found it was a bit discoloured and dirty and so I cleaned it. I Know if the K&N is not cleaned properly or it is over oiled when cleaned this can cause problems with the MAF and I didn't want to take the chance that I'd mess it up. I did quite a bit of research into the paper filters and decided to go for the "Mann" because of the reviews . They are more expensive than most but as I said it seems to be performing very well . Many M3 and M5 drivers use this filter so that's good enough for me.

 

[flybobbie]

Performance of paper filters might vary a lot, think i would go for one with a minimum number of folds.

 

[Silverstar]

This video might be of interest:

https://www.youtube.com/watch?v=GS69owXpGdY

 

[flybobbie]

Yes, i have seen that video, but the paper filters he uses are very open weaved filters, i will post my Bosch filter.
I would suggest the paper filter has a large surface area, but the pleats are tight restricting flow.

 

[flybobbie]

These are the filters used in the video test;

 

[Anonymous]

Following on from the yoof tube I see a Corrado test by 5th gear with various changes

Redex then oil n filter changes then plugs and leads..

Biggest changes were a redex clean and new plugs n leads...about 11 bhp total up in 180bhp

 

[flybobbie]

Well put the K&N back in and all spunky now