Join Date: Dec 2013
Location: San Jose, CA
Vehicle: 1998 SLK230K Grey
Other Toys: B-Modifed Formula Car
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanked 1 Time in 1 Post
Why reloocate MAF of R170?
Evidently the factory relocated the MAF on later cars.
Does everyone agree it is a good thing to do on the early cars for slightly smoother acceleration?
Does anyone have anything to add to this explanation I read by Raindog a few years ago?
"I believe that it is rather turbulence than resonance that causes "bumpy" acceleration. Any bend or change in pipe diameter and/or shape will create some turbulence in the flow and the flowmeter (MAF ) can be "fooled" to give a wrong measurement and since the turbulence is not stable the reading may be going up and down even if the air flow is actually constant. I suppose that this could even cause your jerking.
To avoid such errors, it is good engineering practice to install flow-meters with a certain length of so-called "straight run" piping both up- and downstream. The requirements of straight run varies between different flow-meters but around 5-7 pipe diameters upstream and a little less downstream seems common. So if the air pipe is 3" in inner diameter, there should preferably be no bends or other flow disturbances 15-20" upstream and 10-15" downstream - difficult to adhere to in an engine bay! I guess the basic philosophy is: little is better than nothing and do the best you can. As I recall, there is a perforated plate in front of the MAF in our cars - this may assist in reducing turbulence over the MAF."
Thanks for any new comments on this!