|
|
Al Gietzen wrote:
Al, been there, doing that with the RC thing - .04"/1mm and a cheap
generic plastic fuel filter work very well at all RPM and load ranges. I
can send you some datalogs if you wish. If the orifice is too small, the
ECU has to wait a few tenths of a second for an accurate MAP signal.
This causes a short period of enleanment and a momentary stumble. It's
actually the flow in and out of the capacitance that you're restricting,
not the extremely miniscule flow that the sensor diaphragm generates, if
any. I think most MAP sensors are strain gauges. You want
Manifold->R->C->MAP sensor as your sequence of parts. I've spent many
hours getting this right by trial and error and have extremely smooth
sensor response even at .01 second data logging intervals at 800 rpm idle.
-Mike
Can’t argue with success. Yes, you would not want a very small restrictor upstream from the accumulator. My logic was telling me that the most effective pulse dampening with the least effect on response time would be a smaller restrictor on the controller side. But logic doesn’t always match reality, and I suppose that option was one of your trials.
What application and ECU are you using? Do you suppose it is independent of those things?
I'm running a streetported 12A rotary in an '83 RX-7 using the MegaSquirt fuel only ECU, Weber Alpha 2x50mm bodies (very similar to the TWM bodies) w/ an approximately 19" tract from the rotor face in each port to the end of the TB intake bell. I'm no EE but from what I can tell, most pressure sensors up to the job of reporting MAP are pretty much the same as far as operating theory. A Motorola MPX4250 is the sensor used in my app. Another thing I'd like to mention is that I also have approximately 6' of 1/4" line from the manifold to the RC/MAP sensor combo so there's definitely some extra volume from the hose run. I believe that each application/install has it's variables and no one solution will be perfect for everybody though we can all learn from each other.
Al
-Mike
|
|