darkrider

This recommendation is spot on. The N54's will benefit when using higher boost for aftermarket mapping, but otherwise you are better off running stock!

A properly oiled aftermarket filter shouldn't cause any issues with your MAF sensor, but it's never going to filter as well as traditional paper. The good oiled filters go down low enough that it's rather negligible in terms of filtering, but would only be worth the tradeoff if you're actually seeing proven performance gains.

star69me

Ok cool....

2007 550i

AutohausAZ-Mike

When it comes to using cone style filters or cold air kits, the gains areminimal on a naturally aspirated car. With K&N lifetime filters, you have tobe careful not to over oil the filter after cleaning it, or you will get oilon the MAF sensor and your ride will run rich. The OEM(Mann) filters are more than sufficient for the daily driver car.

biz77

The stock air box and filter is a restriction on the N54 when tuned. See my tuning and build thread here:
https://5series.net/forums/e60-parts...ourney-139155/


Pay particular attention to post # 30, where I show a peak gain of ~4 WHP using no filter in the stock air box, which will be your best case scenario for a replacement filter such as a K&N. I also show a peak gain of ~14 WHP over the stock air box and filter using an Injen intake. Here is the graph comparing the stock air box and filter (red lines), the stock air box with no filter (blue lines) and the Injen dual cone intake (green lines). All runs were performed on the same day in the same exact ambient conditions back-to-back-to-back.





I'm not sure why this forum feels like the stock air box is the greatest thing in the World, but it is in fact a restriction. All of the 1 and 3-series boards have come to that realization and I can only suspect it's because there are many more members on those boards doing significant modding and many making a significant amount more power than stock. The only comments you hear about on this board is how dual cone intakes suck in hot air. Well, do you want to talk about your intake temps or do you want to make more power? I can tell you from the logs used to make the graphs above at any cruising speed and when under significant load, there is at most a 5 degree Fahrenheit delta between the stock air box and the Injen intake. Not enough to make a difference in the amount of power your car is making.


A couple things to keep in mind about my results:
1. I'm not trying to sell anyone anything. If I thought the stock intake worked great I would be telling everyone that it works great, but it doesn't unless the rest of the car, tune included is stock.
2. The results are done on the road, not on a dyno. I suspect that, like me, most of you don't drive your cars on a dyno. You drive them on the road. Testing intakes on a dyno will definitely inhibit them. No matter what anyone tells you, there is no fan on any dyno that provides similar airflow to what your car will see on the road going 60+ mph.

bmwmonkey

biz77, can you explain by what you mean by "The results are done on the road, not on a dyno" yet you posted a plot that says dynojet on the top. Also did you measure your car without the Cobb maps enabled?

It doesn't matter if a dyno lacks the airflow of a 60 mph ride, the airflow is static for all measurements when on a dyno, that's the variable that is being eliminated.

I think this is a pretty clear case for the Injen intake system ultimately being a net loss of power.
https://5series.net/forums/e60-parts...17/#post832216

Booyaazaa

He is using a program called virtual dyno which uses data from a datalog to estimate dynojet results. In the end just changing your air filter will not get you more power. Understanding how your engine creates power is key to understanding what each mod does and how each supports the end result you are trying to achieve. Like I said I run dci's due to increased air volume needs. I don't care if it is hot air since it's going to get hot anyways from being compressed by exhaust driven turbos. All that hot air will get dramatically cooled once it passes the fmic.

IMO for a NA engine I would only do a drop in filter upgrade or the Mr Snorkel type mod which gets air from outside. Other then that your wasting money.

Bill109

is this discussion referring to an e60 with a turbo or is this both turbo and na.
would a cai benefit a n/a car vs the turbo since the turbo needs the cooler air?

Boland01

Another forum N54tech has quite a bit of info on this and it supports biz77's results.

biz77

Sorry if there is any confusion, but speaking specifically to the N54 motor, which has at least been tuned to run more aggressive boost etc. I would not put in the effort to replace the factory intake system on any naturally aspirated car nor would I mess with it on a stock N54 car. The stock intake does become a restriction once you start increasing boost on a N54.

biz77

First question answered by Booyaazaa.

The testing was performed in a manner that made thier product look superior. The manner in which the testing was performed is not how I use my car. I drive my car on the street where airflow is sufficient once the car is moving.

If you want to believe these results from someone trying to sell you something, then by all means do so. It holds no water with me, but neither do vendors claims of thier aftermarket intake systems showing often huge gains. I will take independent infromation based on real-World results over vendor claims.