You need to l listen at the safety brief in the morning - every track day there the same thing.
"No timing of any form is allowed today" Doesn't stop anyone but that's why I said you are not allowed - they even mention you can't have your mate on the wall with a stopwatch and no using phone apps - The guy in the GTR just laughed and said mines built in
Never thought I was that quick to be honest Captain I think does a 1:26 in an NA - he did spend a lot of time there so he knows the track, one of the guys from DJCC is supposed to do sub 1:20's - Tiff has done a 1:10 (or so I read)
Either it's a relatively new thing that there is no timing allowed or I'm never listening properly at the briefings. Probably the latter.
Tbh I haven't done a track day at Castle Combe in quite a while now. I know Combe very well as I did loads of track days/race days there each year but mainly through the late 1990's up until 2007/08.
Best time's I ran where; 1:39:00 in my unmodified 1992 Rover 214si, 1:45:45 in my unmodified 1996 Vauxhall Corsa Sport and 1:35:28 in my 1998 Ford Mondeo ST24 again unmodified (apart from an induction kit).
When I started doing the track days it was so funny in comparison to today ~ no queues, just turn up & pay (around £20/£25 odd), overtaking on corners allowed (not even mentioned in safety briefings as far as I recall), you could use hand held cameras in car and no helmets needed as long as you where driving a tin top. Old school rules.