Resurrecting this from the dead.
I did some testing on EOI over the weekend and I have to say, that your statement about 280 working for everything but highly modified WOT is accurate.
I set my EOI to 280 degrees and lost some power according to my data logs. I have a 232/240 cam with a IVO of 31 degrees at .006 ATDC and IVC at 71 degrees ABDC (after bottom dead center). At the exact same RPM/gear/speed between two logs, my original setting of 330 had higher cylinder airmass and higher maf lb/hr compared to the 280. I believe that since my valve is opening sooner than stock, I am getting better mixing by starting injection earlier (piston closer to TDC on intake stroke) compared to starting it later with the 280 setting.
But I do want to make sure I'm thinking about this conceptually correctly when it comes to interpreting the number used in the SOI table in our tunes. The tune description for the SOI table is that it is in "crank degrees BTDC". In order to properly 'reference' TDC; 0 degrees = TDC where 360 degrees BTDC (before top dead center) is actually the start of the intake stroke so it is the same thing as 0 degrees or TDC. So in order to properly interpret the SOI number (in my case 330), you have to subtract 360 degrees to get you your crank angle piston position ATDC (after top dead center) of when injection starts. In my case 330 - 360 = -30; or 30 degrees ATDC on the intake stroke. Since my IVO event starts at 31 degrees, this coincides well with my specific intake valve event. Now for an SOI of 280, that would be a start injection piston position of 80 degree ATDC, or well past my 31 IVO event. Is this the correct interpretation of the crank angle degrees for the SOI table?
How about for EOI? With my 330 SOI, my EOI was 210, so would I subtract 180 degrees for the ABDC or BBDC piston position? So for my EOI of 210 - 180 would be a EOI piston position of 30 degrees into the compression stroke? The EOI for a 280 SOI setting was 163 for me.
The reason I have some confusion on this thinking is when I calculate the total crank degree angle injection time for my 330 SOI setting, I get 180 degrees (30-180 = 150 crank degree sweep to BDC plus the crank degrees to EOI of compression stroke of 30). But, for the 280 SOI setting, I am coming up with only 83 degrees. 180 degrees of injection vs 83 degrees of injection just doesn't seem right to me, so I must have this confused... No change in in fueling was observed (same .87-.88 lambda and basically same pulsewidth 3.7 vs 3.6 ms)