Originally Posted by
Cat 1
OK... Lots of theory flying back and for the so here is a little CCD (Crude Canadian Data) for you - Put my e-pressure setup to the first test - Seeing if it could indeed supply pressure as intended .. The setup is a simple brushed speed control with a linear curve (0-100%) on a mixed channel from the throttle stick. at idle - no pump - at full throttle - set bleed needle to about 50mmHG. Started up and Quick tune showed my fuel curve is now is a very flat S curve - much flatter than before - throttle response is very impressive as I think the fuel pressure is now leading the ramp up and its acting a bit like a accelerator pump - looking back at video I think I can decrease my throttle servo slowdown. I know I am static but the engine runs better than It ever has - At 50mm I have leaned the top end solenoid pulse by 30-40% and idle is unchanged -
So.. I know Bert has reservations as this is not going to forward load changes but the next stage is to take the control of the pump off the radio curve and give it to the RPM curve (using a simple MPU) - I have found some good engine load vs prop RPM data and think I have the math figured for a first cut at a "control strategy" based on Static RPM and unloading rise. Control shown by the pump systems very good and I'm hopeful a "simple" system will work with only a few parameters needed...
Not the best video but was busy today and in a hurry . This was the very first run - Last runs with tuning were approaching the "magic" zone.
https://www.youtube.com/watch?v=s6qn...ature=youtu.be
That works.... pressure response is better than I expected... only consideration is the added components, and something else that can fail... it does work rather well.... if you can get it all into one small box, to keep things tidy... its a move in the right direction to get rid of that crap trap, so you gain a few components, and you loose the trap bottle.
Originally Posted by
Glowgeek
Yes, I failed to mention the inlet check needed for 4 strokes. I have a set of Saito twin check valves well suited for the purpose.
Edit: Looking back at my posts it appears I failed to mention that I was talking specifically about 4 strokes. Sorry about that.
Yes, from the 300T, and it worked rather well... the odd fire 130T had the diaphragm pump with the same check valve.
It certainly would keep things simple