honestly i wish you could guys hear my motor..... the v3si is a silent trim charger so it sounds how it did before without being charged, but at very low revs 1-3000 rpm you can just hear it spooling, at very high revs all i hear is blow off noise, its a very very mecanical noise, but perfectly in tune with the s54, its just works, its fab, most people would not detect the s.c noise at all! but ontop of the s54 noise which is completely present still, its sounds like a monster, it really is very impressive.
390bhp normally aspirated is fab, i bet that feels so nice to drive, what are your cam specs?
what i love about the s/c power delivery is the torque all round and driveability is astonishing... the car drives better than it ever did stock, the tuning is bang on, no hesitation, no flat spots, just power from idle to redline, also fyi Ess weighted the stock parts and matched the s/c kit so it didnt add extra weight in the nose of the car...... email em for a more detailed answer ;-)
on 100 octane the car made 460 bhp... on weaker fuel it drops considerably as the car pulls timing.
if i could liken how the z4m Ess feels in the car?? it feels like the engine has been swapped in the night for the V8.... power, torque, and complete drivability.