Here in Sweden a company called BSR (www.bsrab.se) sells a step 3 upgrade for 850T. It includes chip, fuelpressure-regulator, airfilter, 3"downpipe and exhaust, supposed to give 315 hp(sure). The reason for the regulator is that, at 1,25 bar verboost, the fuelsystem can't supply enough fuel.

With a 1,2:1 regulator the engine gets something like 5% more fuel.

I wouldn't remove the regulator without removing the chip, cause the chip assumes the regulator is there, and then it might run a little thin on the air/fuel mix. Check if your ECU has been modified, and in that case where and call them!

From your description, it sounds like what we call a "rising rate fuel pressure regulator" (rrfpr) and if so, it's suppose to add more than stock fuel pressure to the injectors at full boost ONLY. I'd gather then that someone has probably altered the turbo boost and that's alot higher than normal.

Simply disconnecting it wouldn't lower the cars power in the lot as that salesman said but maybe it was causing other problems? I know that if it's not adjusted right (too much fuel pressure), it'll slow the engine down and visable smoke might be seen from unburned fuel. Too much is not a good thing but the idea of it is to add more fuel when overboosted to prevent detonation during a lean condition while overboosting (very bad).

Unless you're using a fuel test guage and calibrated turbo boost guage to calibrate it, I wouldn't hook it up again (its vacuum line that is).