Filters..

[561design]

I've never thought much of aftermarket air filters. Unless you have alotta work done to the engine, you really don't see significant gains (dyno). Most studies I've seen show only about a 5-6hp increase. On the "butt dyno" I don't really feel a difference either. Supposedly you really can't feel an improvement on the butt dyno unless it's 10hp or more.

However, I never paid much attention to the additional mileage gained after install. I do remember alot of problems with the MAF's and CEL's on my car after install. Oh and the arguments with the service department.

***DISCLAIMER: All of this stuff occured on a VW and NOT a Streamline filter.

I understand that ISO procedures are related to the production aspect of a product, but I still find it hard to believe that it won't cause premature wear on the MAF sensor.

I've never had a BMW previously. How does the service department react when you take it in with a cone filter installed and not an OEM one?

 

[sp3ctre]

I've never thought much of aftermarket air filters. Unless you have alotta work done to the engine, you really don't see significant gains (dyno). Most studies I've seen show only about a 5-6hp increase. On the "butt dyno" I don't really feel a difference either. Supposedly you really can't feel an improvement on the butt dyno unless it's 10hp or more.

However, I never paid much attention to the additional mileage gained after install. I do remember alot of problems with the MAF's and CEL's on my car after install. Oh and the arguments with the service department.

***DISCLAIMER: All of this stuff occured on a VW and NOT a Streamline filter.

I understand that ISO procedures are related to the production aspect of a product, but I still find it hard to believe that it won't cause premature wear on the MAF sensor.

I've never had a BMW previously. How does the service department react when you take it in with a cone filter installed and not an OEM one?

I think you have a good point there... it's the fact that there may not be an obvious benefit that is making me reluctant to fork out for one of these filters over the stock one.

However, I do believe it is still a panel filter, not a cone... either way, if they saw it I suppose they could bitch about it (knowing BMW!)... although to be honest they'd probably blame the faulty rain sensor on run flat tyres while they're there!

I may be able to get hold of a K&N to test at some point, in which case I'll happily write it up on the how-to section, along with findings in terms of feel, performance and sound, but at present I don't think it's high up on my list of purchases.

Who knows, I may be surprised

 

[IMZ4N]

561design

The filter that I have fits in the OEM filter box. It is not a CAI, which is the cone type you speek of. I don't know if there is any hp gain, what I notice is the difference in the shifting of the steptronic trans. With the stock filter I was not able to get second gear when I wanted it ( needed it ) when in the twisties. With the HP ( Streamline filter ) ,I am much more pleased with the ability to get second gear in that instance.

The increase in MPG is an actual measurement not what the computer says ( they both agree there is an increase ).

I tell my service guy that I have an after market filter and that I would like it to be there when they get done. There has not been a problem to this point. There again it is not a CAI.

 

[561design]

I was refering to both panel and cone style filters. I imagine the panel filter would reduce it's risk of contaminants from being in the stock airbox. But I imagine it would still cause premature wear on the MAF. I'm also interested in seeing what the ECU's parameters are for airflow. Having more air is great but not when it's out of bounds for the ECU. That's when the CEL's pop up.

 

[IMZ4N]

561design

I can not answer that one. I have had mine in for a year and have had no problems. I'm not very technical that way, sorry.

 

[Rick Hunter]

I've got the K&N filter in my box. Haven't noticed anything good or bad yet.

 

[zee42]

I have the cone in the Gruppe m....no problems

 

[Battlewagon]

I was refering to both panel and cone style filters. I imagine the panel filter would reduce it's risk of contaminants from being in the stock airbox. But I imagine it would still cause premature wear on the MAF. I'm also interested in seeing what the ECU's parameters are for airflow. Having more air is great but not when it's out of bounds for the ECU. That's when the CEL's pop up.

A properly oiled panel filter will not harm the MAF or wear it out prematurely. Part of your annual maintainance on these cars should be to spray down the MAF with MAF cleaner anyways whether you have an aftermarket or stock filter.

The Streamline filters are precision oiled by robotic sprayers and the nice dry packaging that you receive them in is your assurance that they are safe to install.

You will never see a CEL with these panel filters as the stock DME can handle the 20% flow increase easily.

However, once you add headers and full exhaust, you might want to think about aftermarket software to pull everything together.

A panel filter is one of the easiest and safest mods you could do. If you are worried about the dealer making an issue of it, easy, swap in the OEM filter before you take the car in. Simple.