It's definitely something I'd like to understand more.
On a log I've compared recently, I've had very slight FLKC appear at 6.8k after the PI ratio was decreased despite running the same timing. However, the IATs are also 10C more on the most recent log so I'm not willing to put this down to injection ratio alone.
It may also be worth noting that @
Shiv@Openflash uses the OEM ratios for the OTS maps. I've also heard that one tuner relies almost solely on DI for boosted applications and only introduces PI when the DI capacity is near it's limitations. It'd be nice to see some results from actual testing, and I recommend that if you do fancy testing that (a) you know what you're doing and (b) that you do it in similar conditions.
I am running a non-standard ratio map on my car, but as I've not had time to change and test for comparison sake I can't even be sure there's much/any benefit to having changed it.
This is as it currently stands:
My line of thinking is that the DI will be used to help prevent knock/cool cylinders in the mid range and at low RPM with high load (20% rather than 50% OEM). When the RPMs get higher and the DI capacity is getting near a "safe" limit then I re-introduce PI at a slowly increasing rate, but hit near stock levels at peak RPM as the ignition timing is increasing.