In Reply to: K&N Intake posted by SSW on September 05, 2001 at 19:24:44:
I've been playing around with the intake on my M5 for a bit while I rebuild the top end and it should be easy to put a K&N in. The lower sensor is the air temp sensor and you can put it into a shield on the intake side (not engine side) with probably decent results.
HOWEVER, I have heard that the M5 intake is pretty well tuned and should not be messed with. I do not understand how exactly this is so because there really is not much resonance charging possible at that distance from the cylinders (plenum and air horns are about it for that), but I've heard reputable people claim that they have tried changing it on the dyno and lost power.
Intake sound is another matter, however, and is the only reason to use a K&N, IMHO. Most people are psychologically convinced of the power from the sound increase. Very few K&N setups make any power.
If you like the sound do it, but don't expect any power increases. There is a lot of development work that goes into an intake (I know, I did a lot of it for some near-400 HP cars) and, trust me, we did not leave out such obvious sources of power. Yes, noise standards are a limitation that precludes K&N use, but even so.
Anyone know if K&N makes a cold intake for a 1991 M5?