VE tables vs. engine characteristics
Turbo Mini Forums

To close this thread from the original question about the effect of VE tables, I will now conclude the following (but the AE issues deserve more discussion in their own right, more later....)

With most of the accelleration terms vetoed I put the 1000cc injectors back in a couple of hours ago and reset "ReqdFuel" accordingly.

Starts / runs / hot restarts, all absolutely fine despite the much lower "reqdFuel" (and hence much lower pulsewidth) needed by the bigger injectors.

So, I'm afraid, StevieTurbo, I can eliminate your concerns over the RC/Honda injectors. I can actually get a better idle than with my previous 640cc ones.

However, the idle isn't as good as Paul's yet - I've seen/heard it for real at MITP - so I know what I have to work towards.

What was really interesting is that a swing of 0.1mS on pulse width, by cheating the mathematical fudge of injector openning time, could swing the AFRs at idle by nearly two (ie, high 13's to low 15's),

And, a swing of 10% on the outer VE table could put their AFRs equal to the inners with fixed timing rather than altering the individual injector timings.

I'll start a new thread in the "Trials and Testing" part of the forum tomorrow but I now think that - if you're running individual pulses - (Paul doesn't but runs the single hybrid mode) - then skewing the VE tables has as much an effect as altering the injection timing - if you can get the injection timing exactly within the right window and it's short enough not to overlap.

Schrödinger's cat - so which one am I ???

Nice to see that you're making good progress and finding interesting facts about the dual pulse behaviour. I suspect that even though you have two ways of getting the same result, in the end there's going to be a method that will be easier to tune for the entire range. But I look forward to see what you find out.

As for the TPSdot threshold value, you should start at around 50%/s and see if you get false triggers. If you do then you'll either need to increase it or find a way to reduce noise. In the case where there is no false trigger then you may want to lower the threshold so that you can have a more sensitive AE setup which should be a good thing with very large injectors.

Jean

http://www.jbperf.com/

Schrödinger's cat - so which one am I ???

It may be a good idea to start a new thread on AE once we get the hang of it.

We took the 998Ti to Stanford Hall last Sunday. Gave it lots of beans each way on the A14. A couple of times we had the familiar stumble when I booted it at around 2000rpm. We know AE causes it, because we have video and data evidence from the RR day, but have not got round to fixing it.

I've still got AE set to 100% TPS.

Anyway, last week we reduced the AE pulse widths and increased the sensitivity. Just took it out for a blast and the stumble has gone

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."