If you feel like a new chassis will make you faster, get one. You need to eliminate everything you think could be costjng you time. If you get a new chassis, get it set up by one of the best, and you are still a little off, you KNOW without a doubt that you have to focus on tires.
The only question is, is it worth $4000 to you to figure that out?
The only question is, is it worth $4000 to you to figure that out?