OK, a bit of an update on all this....
Firstly, cam timing:
I'm finding that increasing the intake timing sooner helps a fair bit. The timing table don't allow for -ve timing, so I'm assuming at the moment that the setup is a bit like the Honda VVT-I or Rover VVC setup. So there are two main points to consider.
- Advancing the Intake cam increases cylinder filling efficiency, but also increases exhaust overlap.
- Advancing the exhaust reduces overlap when the intake is advanced.
So the idea here is to advance the exhaust at low / light cruise to reduce pumping losses (maybe), and increase economy. Also have the exhaust and intake advanced at lower RPM high load to both reduce overlap and improve cylinder fill. Ten at higher RPM, bring the exhaust timing back to "0" advance to increase overlap and use the exhaust pulse to help fill the cylinder. Anyway, that's the theory. Get the timing wrong though and you get the exhaust contaminating the intake charge....
Secondly, I get the feeling that the standard injection timing is too late. Especially in the lower RPM / high load cells. Given the valve timing, I'm going to try and advance the timing a bit to see if that helps. Other than that, the last big test showed fairly good results. Averaging 13.5L/100KM while towing a large cage trailer full of holiday gear. It pulled OK for the V6, but I still miss the cammed 6Lt when towing.....