Been thinking about trying a smaller pulley on my G40 charger which has got me thinking about the implications of such a move..
What is it exactly that determines how soon it would need a rebuild?
Is it simply that the increased rpm means proportionatly shorter service intervals or is it that the boost pressures involved when it's spinning that fast causes additional damage to the seals/bearings etc or is it a mix of the two?
Reason I ask is that with my setup (Full blend charger, 65mm pulley, PSD intercooler, larger throttle body, big valve head, 1473cc) the pressure in the system is reduced from a standard setup significantly, sub 10 psi on my gauge.
If it's the boost backpressure (?) that determines rebuild time then my basic maths would suggest my setup with a 58mm pulley wouldn't result in significantly different boost pressure than a standard setup with a 65mm pulley? Logic then follows that rebuild time would be reduced from how it is currently but in absolute terms still reasonable?
Is my reasoning sound or am I barking completely up the wrong tree?
What difference would running a standalone oil supply setup make?
Cheers!