I agree with 303, the blinky settings in an ESC are often very aggressive in the throttle ramping and can make the car have more punch than almost anyone can control. BUT, if you have a radio with servo-speed adjustment like my Sanwa MT-4, 20-30 ticks to slow the slew rate in the throttle can make even the most punchy modified motor much more tame.

I found it easier to leave the ESC on a more normal setting and take the excessive punch out with the radio because you can adjust the settings during a practice run instead of pulling the car off the track and plugging in the ESC. When it is running right, the car feels a lot more like it has an engine instead of an electric motor with its max torque at 0 rpm.

As for boost and turbo, most of my running modified has been with an old LRP Stock Spec V2, and its first tick of boost is a LOT of boost. I imagine if I was using my Hobbywing with its extremely fine boost and turbo tuning I would add a little to keep the car accelerating down the end of the straight, but I am still a little scared of overshooting the sweeper and then visiting the parts section of the hobby shop.

On a related note, turn down the minimum drive or initial throttle setting in the ESC, if you have one. Some stock settings have 7-10% throttle as the minimum drive to prevent cogging of high-timing strung out 17.5's, but 10% throttle running a 4.0 is going to make lining up on a starting grid or putting slowly around the track a little difficult.