Thanks again Didcoop. Below are the results from the day for LE#134. It was a bit busy to take it all in but although the graphs below show it wasn't far off the manufaturers quoted details of 220bhp, there seems to be a bit too much of a spike and also concern that it was running lean.
Its down to be serviced by Rog in the next few weeks so I'll get it checked but strikes me that a trip to Flea beckons. If anyone can advise then I'd be grateful. There was thinking that the solonoid or actuator might be misbehaving - but lots of this went over my head so if anyone can explain in simple terms (ideally using puppets).
For info. its completely standard 98 LE. Supersprint exhaust, engine around 50k. On the day for Brooklands I filled up with shell v-power thinking it would do it good and weirdly it felt more sluggish than usual - but probably all in my head.