Forgot to mention that I got a SB a few months ago. Not cheap, at around 250 USD. I had the car in for some servicing. Guy says: "ever tried a sprint booster? I can hook one up in two minutes and you can take it around the block". I did so, walked back in and gave him the cash. HUGE difference. While of course I can see no way in which it actually adds to the speed of the car, it DOES add to the chances of dominating in a race. When I put my foot down from a standstill, the car GOES now, instead of going and making a cup of joe before deciding to haul ****.
Just my 2 cents.
Incidentally, with the SB,code 3,needswings CAI, I'm mid twelves. about right I guess...