12 b


My objection to all EFI's on the market is; I am not sure what they will do in some unforeseen scenario. In an aircraft it is a life or death environment.  What goes up MUST come down.


The flooding of all new RX8's is a good example.
Ford was involved with Mazda then and Ford extensively tests all new vehicles. They missed it. They also missed it on the apex seal oil injection.

I don't begin to know what some bodies EFI is going to do under all circumstances.  Even if I had total access to the source code.
If it was written in C it would be Greek to me anyway as it takes years to learn C. With most EFI's the source code is secret anyway.

I suspect this is the reason the FAA refuses to certify EFI and they do have the source code.

I have written my share of complex software in assembly language and it is near impossible to predict all possible situations or scenarios.
At least In assembly you know exactly what every instruction is going to do.
In any high level language you do not. BASIC however is much much easier to learn than C.

That is why I suggest one Maximite per injector.  It is as simple as possible and highly redundant. Same goes for the throttle pot and a 555.
If you want engine parameter recording and or instrument  panel display use a separate Maximite and software. If there is a bug in that no big deal.

If there is a bug in your EFI software that is a big deal. Megasquirt is not widely used in aircraft. That is true for all after market EFI's with the exception of Tracy's. Tracy had his share of unforeseen problems as well. They called it glider time :-) He wrote it in assembly language so he knew far more about it than anybody using it. He did not release the source code until recently and believe me it was very complicated. About half just to control the ignition.

I used to be a fan of Megasquirt back when they published the source code in Motorola 6800 assembly language. The 6800 was simpler than the
6502 I used so I could at least understand what they were trying to do.
They now use C.

That is fundamentally why we fly the Motec TTC at Oxnard airport.
If the engine quits we are always near enough to the air port to dead stick it in.


Paul Lamar


Hi Paul,
    I cannot understand why anyone would want to go through all this
B.S. for EFI when a simple mechanical throttle body is just as good with
MANUAL control of leaning (Ellison or Rotec) I had an Ellison in my
previous Long EZ for EIGHTEEN YEARS ! It NEVER gave me any trouble and
was the most economical device ever. When I took off the original
antiquated carb (M.S.) the improvement was amazing, more power, better
economy etc. It appeared to be extremely resistant to carb icing as I
tried to get it to ice up on known icing days, it wouldn't ice up!
    Cheers Chris Hoskins.

I think you will need two if your looking for 250 HP.

Paul Lamar

Hi Paul,
   I have a rotec TBI 48-4/5. The guys at the factory tell me it is good for 300HP easily.
   Chris Hoskins




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