Did you fit your coilies as shown in the box, cos the springs are the wrong way around, the helper spring should be at the top or at least they are on my spax. Other than that, schweeeet looking engine bay man and i bet it sounds immense! 
Helper springs should be at the bottom.
Reason? On my super cool racelands, my spax, my mates kw's and my other mates spax the helper was at the top.
Just had a look about online and it seems that the big hitters are saying run helpers at the bottom on the front and helpers at the top on rears but cant give any reason for this?