Get underneath and pull the wastegate arm and see if its strong.. Run the engine spray wd40 around the inlet manifold where it joins the head, if it revs up, your gasket is shagged and thats where all your boost is going... Saying that if your on fmic you have alot of pipe work so spray wd over every join and if it revs up its leaking from where you just sprayed. Hope this helps 
Edit: aswell try not to coal on full boost, coaling means everything is getting very very hot, thats how you melt stuff, then you'll be going backwards not forwards
Edit: aswell try not to coal on full boost, coaling means everything is getting very very hot, thats how you melt stuff, then you'll be going backwards not forwards
Doesnt even own a 306.