adjusted the pressure back down to 2.5 bar, and spent 10 mins tweaking the map down a bit as well, and opened up the max lambda trim to -20%.
as expected it stil trimmed some off - but only up to 18%, so not a bad guestimate.
car goes well, and now I've got all the dwell time I'm ever gonna need, so it's a resounding success.
just got to get this oil burning problem sorted out now - head and sump is off, bores look ok.
I CT'd it before I took it apart and all four were 175psi, so the top rings are fine it seems - it must be an oil control ring problem.
however, something unrelated I found was badly worn big end shells - the incident with the oil cooler hose did take it's toll then it seems, so a new set of BEs will be going in, and make sure this time I don't run it low on oil again.
it's worth noting that it only idled without oil pressure for about 30 secs - and thinking about it now I've had a bottom end noise on startup ever since - I think it was because the engine was fresh the damage occurred - on a high miler engine losing pressure at idle for a few seconds probably wouldn't harm anything.