Project E39 M5: K&N Filters and HPS Intake Hoses
So far, the goals for the modifications to our BMW E39 M5 project have been to enhance the performance of our ultimate driving machine without straying far from its original design or ruining its daily drivability. Will these goals always remain? Probably not, but before they change we're going to continue to extract every last bit of “no bad side effect” performance out of our M5. In this installment of Project E39 M5, we will test two very easy to install intake upgrades – the high flow K&N drop-in filters and HPS Performance Parts silicone intake hose kit. We will be doing individual dyno tests for each part to see if they will free up the S62's intake tract and yield some easy power gains.
Although the E39 isn't the latest performance offering from BMW, it was produced at about the start of the new era when manufacturers started to really optimize the peripheral parts of their engines in order to squeeze every bit of efficiency (aka MPG) out of them. Modern vehicles intake systems are so well engineered that it's usually very difficult to find significant power gains from simple intake bolt-ons. Gone are the days of being able to bolt-on a well designed cold air intake and experience double digit gains.
The E39 M5 is no exception to this new trend towards engine efficiency since it was one of BMW's technical flagships at the time of its production. The E39's S62 comes with a short tract, dual intake system from the factory that seemed to be pretty high flowing. So, we were a bit skeptical going in about being able to find any real gains from just panel filters and silicone elbows.
The K&N high flow filters are washable and reusable. They are also covered under K&N's bulletproof million mile warranty. On top of that, all K&N filters are backed by K&N's Customer Pledge. K&N will stand behind their products and will warranty costs caused by legitimate claims of any damage specifically caused by their filters.