when i got back into racing my local track, 360 rc speedway - rip, used to run black can paragon. grip was always amazing. 360 closed... and now i run at horsham rc and last year we used jack until we couldn't buy it anymore and started using either SXT v3 or sticky fingers. if you're lucky enough to have a bunch of racers jack/sxt/sticky is fine, but if you have a smaller crew you NEED ground effects (and maybe some aspirin, or a stiff drink as that stuff just smells)