Is it possible to take the restriction of the crossfire. As we know we are restricted to 155 top speed.
Has anybody done this if so what difference did it make to 0-60 and top speed.

 

ECU reprogramming will set off the limiter.
A number of companies do this the ones i can think of right now are:
Powerchip (Well rated and cheap, but not from well known company)
Renntech
Kleeman
Startech (Brabus)
Carlsson (Europe Only I believe)

You can actually do this yourself, but I am not exactly sure on what you need and how to do it, but there are people who remap the ecu's themselves.

And one more thing... if you are talking about a regular crossfire I don't believe it is limited by the ecu, but by the engine performance...

Hope this helps.

 

Removing the limiter will not affect 0-60 times or any other times just top speed if the car is capable of more than 155.