Mysterious big loss of power/drive on Spa circuit during parade laps.🤔

[Pride]

Does anyone have any suggestions please.

Last Saturday during the parade laps on an open straight I floored the throttle in 3rd, 4th or 5th gear.

When the revs reached about 6500-7000, the whole car suddenly jumped and the revs rushed up but all power was gone.
My first thought was that I blew the engine and I immediately slowed down. To my surprise, I noticed the car was still pulling well when I gave some throttle. There was no smoke, no suspicious sounds and no lights on the dashboard - everything seemed normal?

I continued driving and everything seemed just fine under normal acceleration and loads but as soon as I gave it maximum power over 6000 rpm the same thing happened again and again.

After 3 or 4 times of this happening I decided not to go flat out above 6000rpms. Now I want to know what might have happened, because it was a first time experience in 21years of ownership, much spirited driving, lots of track days and a far few wild parade laps at many circuits and now I don't trust the car like before.

Has anyone ever experienced this fault and if so what cured it for you???

I will be sprinting it up the Beaulieu house drive tomorrow morning and afternoon when the chequered flag drops, it may well do it again under these conditions so I will report back as to what happened.