when the dumpvalve is dumping, the airthat its letting our the management system thinks the engine is using, so it puts in the fuel to match, this makes the car overfuel whilst it is dumping.

ever noticed that RSTs with dumpvalves work better with flamerkits than those without DVs?

also if youre on part throttle and th car is boosting but the dumper is open (ever got it where its hissing on qtr throttle?) then the car will over overfueling its tits off.

MAF based cars aren't designed with dumpvalves in mind... if youre gonna use one, use a re-circ one