Shakespeare county raceway 30-10-10

[volvo-tom]

just a quikck vid of my 480 being driven by my dad, we got thrashed by alot of impreza's and a modded 240 but won 2/3 races against another 480 turbo (black) which was a surprise as the owner had had his chipped. and ours just had a £16 boost controller and a cone air filter! we upped the boost throughout the day and found that 22psi is the best pressure to run at becuase anymore causees boost spiking. but its amazing that the little engine can take this much boost without adjusting the fuel!
[ame]http://www.youtube.com/watch?v=GMedQEBCoWw[/ame]
although oldly as soon as i put on the cone air filter (standard boost) the car still makes a flutter dump sound(you can probably hear it in the first part of the vid), sounds awsum but wot do u rekon cud have caused this and is it something i should be worried about?

cheers, tom