Originally Posted by
Haz
firstly, has the ecu been modified? this is the main thing.
setting the afm to 650 is mainly done to increse the fuel coming on boost, adjusting it has more effect on idle as once it sees 5 volts it sees it as full. also as its a hotwire type temp can affect it too, on a couple of cars i've played with even opening the bonnet can make a difference.
the throttle switch has a 'click' in it, this activates the ecu to its base map settings. you could rotate the sensor just enough so it never clicks and try to adjust idle using the idle screw, tbh the idle control valve would help here. leaving it disconnect will work but you loose the 'accelerater pump effect' of the ecu as it only reads map/afm. at higher revs the ecu will see the afm at max, and with ecu mod it sees boost differently so it wont run as smooth but WOT isn't affected.
a rising rate reg helps for an increase in boost, but larger tb and cam affect the full rev range so you'd be forever playing with it.
without modifying with a bypass hole volvo 740 turbo green injectors with factory resistor pack will be the smoothest you can try, runs nice throughout the rev rang. boost limit varies between 18-21psi on different cars but should be enough to crack 200bhp. with your setup i recon 12/13psi is gonna be the max boost but you'll prob make 175bhp at that.