sequential injection timing by request

[Piledriver]

Pics attached.

engine-and-sequential-settings.jpg

timing-table.jpg

timing-table1-ms3.jpg

[Mr.Larsen]

Thanks for sharing!

How come you don't use End-of-pulse (normal) as Timing Trigger?

[jhoefer]

I'm confused by the injector timing you've chosen here. Starting the squirt at 90 degrees BTDC means you are injecting fuel on the compression stroke just after the intake valve has closed. That fuel then sits there for around 420 to 450 degrees of engine rotation before it can be sucked in during the intake stroke. Are you doing it this way this for a reason? The more common setup for this is to inject so the end of the fuel squirt reaches the intake valve just a few degrees before it opens, typically resulting in an initial setting of 400 to 360 degrees BTDC (depending on cam timing, rpm, and travel time of the fuel charge).

[Piledriver]

OEMs typically start to inject just as the valve closes.
YMMV.

That strategy and table provides the richest mixture reading for a given amount on fuel on a mildish cam, on MY engine.
Gives maximum time for the fuel to evaporate on the very hot intake valve and port.
Also noticeably improved drivability once VEAL got done with the VE table changes.

On a wild cam, (high overlap and free tuned exhaust) it would probably be far better to use the other strategy.
With a turbo stopping up the exhaust, you'd have to try both strategies to know what's best, might vary greatly by load.

It only costs you a few minutes to find out, the WBO2 tells all, at least for this.

[jhoefer]

Interesting. I suppose when it comes down to it there's not really a fundamental difference between the two strategies, you're spraying against a closed intake valve either way (as opposed to spraying into the open valve). Like you say, it's just a matter of finding what works best for a specific setup, for me I believe that was at about 450* with end-of-squirt timing.