DIYEFI.org Forum

Regarding the math processing time on an Arduino, set a timer and measure the function. Send the result through the environment's serial monitor. At 10,000 revs a combustion cycle happens every 0.006 seconds. That's quite a long time to figure out a shot of fuel I think. If measurement proves not en...

Hey there Noisy, sounds like a fun project you're working on. I think you can get there with an Arduino. It's certainly a great learning process. Having to work within possible hardware constraints often produces creative solutions. And that process stays with you for life. Anyway, I have a couple o...

Perhaps so far in our discussion there has been a misunderstanding in the definition of a 'closed' throttle. Certain I've been referring to a closed throttle to be idle throttle demand, not fully closed. I suppose looking at the concept of a CLOSED, i.e. 0deg throttle, yes there are no pumping loss...

It depends on the engine. Direct injection? Port injection? I was just wondering is all. In the example you gave, PatAir 'outgoing air control' had the compression stroke reversing 85% of the intake charge back out of the cylinder, backwards through an open intake valve, and back into the manifold,...

[Example regarding MultiAir early valve closing.] You keep the intake valves of a cylinder open from the overlap TDC to 30 degrees after the overlap TDC. Then you close the intake valves. The volume of the air (or mixture) entered into the cylinder is about 1/8 of the displacement of the cylinder. ...

Thanks Manousos, for the short treatise on some of the differences between the two modes of operation. That is an interesting method of essentially eliminating the compression stroke, and taking good advantage of high expansion ratio. During 'outgoing air control' which crank angles are the fuel and...

Best of luck with your last few months of classes, jtw. [Keeping] all valves closed on deactivated cylinders, but this is not what decreases pumping losses. Pushing a piston up against closed valves, is the same as a pulling a piston down against closed valves. The two are the same in that neither a...

jtw11 wrote:As much as I wish it was, I'm afraid the dyno these tests were performed on does not belong to me, no.

Oh, I didn't mean 'do you own a dyno?'. I was asking about a 'motoring' dyno.

Hey there, jtw. Did you say you had a motoring dyno? The VAG GDI motors mentioned in your prior post have a mechanism on the cam to disengage the valves on the unused cylinders, that in order to eliminate pumping losses.

The 1000-units-per-month relates to a retail operation selling the OEM MegaSquirt products. If a person wants to design a specialized ECU product using the MS code as a base, then the high quantities do not generally apply.