4JB1T turbo comparison

[mudgrip4]

There are several turbos available for the 2.8 4JB1T - the VI58, VI73, VI74 and VI87. There are slight differences in size of impeller, inducer, exducer? and possibly housing etc between them. Have been running the VI58 on my current bighorn but tried experiment last week and fitted the VI74 to see if it gave more power or altered torque curve.

Result virtually no difference. Very slightly earlier spool up of turbo but very slightly less at top end. In all, hardly perceptible differences in power - you wouldn't pick them if you didn't know your truck.

So experiment not a great success in terms of power increase, but I do now have a spare VI74 for sale which I will soon advertise. If someone on this site wants one, it appears good - some wear on impeller blade edges but no movement at all in shaft where it matters so bearings will be good. Usual trace of isuzu whistle under boost, runs well, and should give years of service. After maybe $275 for it - $450 from Bits For Isuzu in Akld.