I have never raced one but some of my friends have. From a stop a Mustang should be able to pull. From a roll they pull quite nicely and unless you are pretty modded the S2K will get a stang from a roll. I am talking about GT stangs.

 

Your absolutely right. From 45-90 the S2K is strong. Post 90 the lil engine just can't cut it compared to a v8, below 20mph your not in vtec. If driven correctly you can consistently run 13.7 @ 103 in an S2000, it's just an extremely hard car to drive that fast. Everything has to be perfect and 95% of the owners can't even run a 14.5 in one of them. Putting 3 cars on one to 120 doesn't sound unreasonable, but make sure you get them to run you that long, otherwise it will be a close race(stock for stock).