Buttock-clenching

At the end of a buttock-clenching trip, we landed to find Eritrean helicopters crouched on the tarmac of an airport that had just been bombed by Ethiopian jets.

I would zoom through the uphill left-hander at Coppice at a buttock-clenching 90mph (145km/h) in fourth, but on the climb up to Charlies the revs would fall away and third was needed just to maintain speed up the hill.