When I tried it at 18 Deg I got a lot of overfueling on quickly lifting of the throttle.
The pops and bangs and occasional fire ball from the exhaust was entertaining on track,
but not so great for the road. Car dosnt do it all now im Charged
Back to Op
as advised to a full service and then look at breathing
are you going to fit a new filter or the old trivck of just drilling holes in your air box.
But First of all I would fit better brakes..Braking 20 yards closer to a corner is worth more than a few MPH in speed.
and yes give MOT a try...Blyton is a great circuit for first timers and there is usually a lot of mx5's there so you can chat to other owners and see what they have done to their cars.
Alan

Max5 Mk3 race car 42 sponsored by
http://www.brynhilton.co.uk/
www.masbars.co.uk