Seeming I'm on a roll with the graphing gadgets on DataLogLab (it's like the EcuTek logging thingy but not ), here's another 'interesting' graph with knock. Well, not knock as such, just noise level as recorded by the knock recording gadget the ECU listens to. It's recorded over a 30 miute or so run, all compacted into one funky little graph

For anyone with a KnockLink, the maximum knock recorded here counts as the lowest LED flickering when it's set to maximum sensitivity.



Goes up, just as you'd expect, the higher the rpm. But there's the 'interesting' bit at 4,500 which I remember reading/hearing about somwhere but can't remember why... Anyway, 4,500 I think is the point that the advance is most critical - someone who actually knows what's going on could probably explain it if they felt like it
Whatever. These are the noises that your engine makes, shown as a piccy rather than one of those strange whizzy noises that sometimes get uploaded that make all engines sound like they're Scalextrics

 

The EJ20 engine's volumetric efficiency seems to peak around 4,500 rpm in OE engine setups. Hence it can get a little "sparkley" in that region.

 

Oooo, well there we go!
Ta!