a few wwks ago i went from my stck T3 to a larger airesearch t3/4,secondhand, has a much bigger compressor wheel and inlet, it had no shaft play and seemed in good condition, but i seems to take ages to spool up, i cant even get it to hit 10psi unless its under alot of load, basically it revs out before the boost winds up. i reckon the old t3 was atleast as quick, if not quicker, my mate has the same engine but with an old T4b, and hits 10psi easy and is way faster than mine, whats goin on? Some original photos have not been recovered yet.

got any leaks anywere?

lottsa questions arise, got good oil flow ? when engine off and cool does shaft turn easily ? (btw: Is there much forward to backward motion of the turbine shaft) as ICUL8R asked - leaks anywhere ? What sort of wastegate - is it a very tight fit ? Do you have or can you get an optical tacho to see what speed the comp is turning at idle ? (btw Can start and run car on idle without AFM just dont unplug it when its already running)

got an exhaust on?.... silly question i know but if you dont.. it wont boost as well.

just put the stock t3 back on with dose pipe, and it wont even dose! just flutters, its acting just like the t3/4, it used to dose crazy, with the t3/4, the compressor was barely turning at idle,duno bout the t3, havnet looked yet, i did add a catch can about when all this started, running both breathers to it, and plugged the pcv valve. could that cause it? yea its got plenty of oil flow, and full 2.5 inch exhaust. btw, how much pressure should the actuator rod pull on the wastegate?

u want about 1mm preload on the actuator, enough so it has some resistance and wants to pull ontp the housing causing it to seal

yep you want it to be pulling hard...

''i did add a catch can about when all this started, running both breathers to it'' does your catch can have a filter on top if not i wouldnt be running both breathers to the unvented can

Problem solvered! was just the blooody filter on the end of the dose pipe, not enough surface area to suck the air through, and yea i got 2 filters ontop of my catch can.cheers for tha help

Good to know its fixed, was wondering about this... So the T3/T4 hybrid spools up ok, got a pic of the type as I have one and wondering if I should hang onto it <shrug> Edit: Actually this raises an interesing issue:- From the pure control systems perspective, it makes more sense in terms of stability and fuel economy to throttle the input to the compressor instead of throwing away pressure at the other end...