Hi folks,
I would like to apply a megasquirt system to a Hirth F-33, but before I spend the >$1000 on it, I wanted some basic advice.
This engine has the following characteristics:
Single cylinder, two-stroke, aircraft engine
Displacement: 313 cc (19.1 cu in)
28hp @ 6500rpm
I'd like to use high resolution MAP sensor pulsations rather than CPS or cam trigger sensor as my basic "where is the engine at in its cycle" sensor. If the MAP sensor is connected to the crankcase, it should tell me not only the max vacuum, but also the supercharge pressure, before the piston port opens. From that sudden dip in the crankcase pressure, I should know exactly what part of the cycle the engine is at, and I should be able to time EFI and ignition. It would seem to me there are a couple limiting factors: (1.) The resolution of MAP sensor output, (2.) the latency of the MAP sensor output, (3.) Telling the MS to use X time before peak pressure as BDC.
Any advice on if this is mechanically possible and what MS system to use would be helpful.
Hirth F-33/MAP sensors at the limit
Moderators: jsmcortina, muythaibxr
Re: Hirth F-33/MAP sensors at the limit
I would run alpha-n and leave the map open to atmosphere for barometric correction.ColorDog wrote:Hi folks,
I would like to apply a megasquirt system to a Hirth F-33, but before I spend the >$1000 on it, I wanted some basic advice.
This engine has the following characteristics:
Single cylinder, two-stroke, aircraft engine
Displacement: 313 cc (19.1 cu in)
28hp @ 6500rpm
I'd like to use high resolution MAP sensor pulsations rather than CPS or cam trigger sensor as my basic "where is the engine at in its cycle" sensor. If the MAP sensor is connected to the crankcase, it should tell me not only the max vacuum, but also the supercharge pressure, before the piston port opens. From that sudden dip in the crankcase pressure, I should know exactly what part of the cycle the engine is at, and I should be able to time EFI and ignition. It would seem to me there are a couple limiting factors: (1.) The resolution of MAP sensor output, (2.) the latency of the MAP sensor output, (3.) Telling the MS to use X time before peak pressure as BDC.
Any advice on if this is mechanically possible and what MS system to use would be helpful.
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Re: Hirth F-33/MAP sensors at the limit
Sensing of the engine phase using the MAP sensor is supported in MS2 and MS3, but a crank sensor is still required.
James
James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk
My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
Re: Hirth F-33/MAP sensors at the limit
Did you go ahead with this on the Hirth?
I’ve got a Hirth F23 and am looking into the microsquirt.
Thanks
I’ve got a Hirth F23 and am looking into the microsquirt.
Thanks