You said "autoslalom". Never heard of it. If you mean AutoX, i'm surprised you're nto always in 2nd gear. We design them for 2nd gear - and when we have airport runways at our disposal, 3rd (e.g.: PCA Zone 1 runoffs at Fort Devins in MA).
17s are lighter, cheaper.
Want fast, get slicks on dedicated wheels. Of course, then you;re re-classed against people who will likely kick yu around for a while.
Grant
Grant
gee-lenahan-at-gee-mail-dot-com