I think John has been running his Grids on the track with a fair whack of bhp for several years now and I'd be interested to rear what you might suggest as a suitable track wheel without getting into 'silly' money please ?
Almost anything, within reason. Tyre size, brake clearance, suspension clearance, budget are major factors, aren't they? I'm not differentiating between 'street' and 'track' use because these days using a wheel on the street is like sending it to war, considering the state of my local urban roads...
It's a bit of a '
how long is a...' type question. Personally I think the fact that modern tyres (construction, compounds) are so much better now than they were 45+ years ago has a major effect on the way these cars handle, and it's all too easy to over-tyre and over-wheel them as a sacrifice to looks. And tyres are
the black art. Literally. Wheels are just the things that the tyres sit on.
Back on topic: Richard, I reckon it's probably just crud in your pump. If it's got past the pump's internal filter even a tiny bit of crud can stop it working. Very simple fix!