View Single Post
      06-19-2012, 12:46 PM   #33
e90pilot
Freight Dawg
United_States
54

 
e90pilot's Avatar
 
Drives: E90 325i
Join Date: Jul 2005
Location: Oakland, CA


Posts: 2,109
iTrader: (3)

I just wanted to interject here about some observations I've made regarding valvetronic. I'm not sure why BMW keeps saying the the throttle plate remains in the full open position one the engine is warmed up, because it's simply not true. I hooked up a data logger to my car (2006 325i sedan N52) and logged throttle plate position, pedal position, and valvetronic angle. I drove the car for 45 min and observed the movement of each variable. I noticed that the throttle acts just like a normal throttle plate in any car. If you give it gas, it opens. If you take lift, it closes. If you don't move your foot it stays the same. It doesn't matter weather you're driving on the street or freeway, or just revving while stopped. Valvetronic also increases and decreases with pedal position. When you start the car, the throttle angle is about 10-13 degrees and then CLOSES to about 4-5 degrees for normal idle. Max angle is 81 degrees.

I also noticed something else that's interesting. The throttle plate action is heavily dampened. If you lift suddenly, the throttle and valvetronic will not close immediately, especially while cornering. When increasing the throttle quickly, there is less damping and the response is better.

I'm not sure if there have been updates to the way the system functions since it the generation they installed in my car, but the way it works in my car is contrary to the way everyone has portrayed it.
__________________
--Marcelo
'06 Arctic Metallic 325i | Sport Package | 6MT | Dinan Stage III suspension | Dinan exhaust | 330i manifold swap! Click here! | Active Autowerke tune | 135i Brake Calipers | Deiselboost caliper brackets | E46 M3 front rotors