I've never played with a closed loop system Neil so I have no idea(but what
you say makes sense to some extent). Everything I do is open loop and the
best my new data aq system will read is 200ms(which I use here at the shop
and haven't had on the course yet).
A closed loop system I imagine samples much faster then that, more of a
question for someone like Dave D., or maybe even Jack since he's going to say
this is a wasted post as there's no actual data(not that I disagree with him
when it's actual answers(data) being sought). I know that surging on some of
these early FI Harley's(without a map sensor) is very noticable when running
without the air cleaner in place(wind gusts, leg postion, etc.). Looking
forward to hearing Daves(and others) thoughts on it though.
TD
> Todd;
> You bring up a good point about creating "dirty air" around a scoop
> intake. It seems to me that if there is a significant amount of
> turbulence in the intake it will create a variation in the engine
> manifold absolute pressure (MAP) that could be a problem.
>
> If the turbulence is bad it will create fast pressure waves that can
> be picked up by the MAP sensor. Depending on the system bandwidth (response
> time), the dynamic pressure may be simply averaged if the response time
> isn't very fast. If that is the case, half the time during a pressure
> wave cycle the AF ratio will be too rich and the other half it will
> be too lean. Of course, there are normal intake pressure waves as
> the valves open & close; if an EFI system can deal with those maybe scoop
> turbulence really isn't a problem and I'm "crying wolf".
>
> Any ideas on this, anybody?
> Regards, Neil Tucson, AZ
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