The journey begins - purchased a truck.

Injector mysteries solved. Engine brakes mystery pending.

When my injectors went down January/February, I had my mechanic order a 6 pack off the engine serial number and installed them. I remember driving it home thinking "Hmmm, this thing should be a race car with a new set".

Turns out, after he back searched invoices, they (Freightliner in Joplin) supplied R5235580 which is for an 11.1 S60. Freightliner in Joplin will not back their mistake, and my mechanic is eating the cost. They should have been R5235575. Mechanic had employee install, employee did not double check (and I argue should not HAVE to) part number, yet Freightliner walked away.

Test drove it today, and even bobtail - whammo, boost is back to 36-38lbs and spools up like it used to. I had him order R5235915, after a quick consult with @Ruthless. From what I see, 5 degree spray angle difference and same holes. GK60 motor without piston cooler nozzles.

Midway through this, Fernando got back to me (he's notoriously difficult to reach) and his GK60 550hp 1700 ft/lb tune to run with the smaller (his words) 5575's will result in actual peak torque and HP higher , with the 5915's vs the 5580's.

Fernando's tune was 'middle of the road' , as I was nervous about 'hotting it up' too much, so I'm thinking I'll monitor EGT/boost/EOT and see how it goes. The problem with the wrong injectors only reared its head pulling that last load - heavy/wide/tall/grades/wind - most of the year I'd been light and empty half the time.

@DDguy has offered to remote tweak the tune, I'll just have to clear out my old HP laptop , buy a cable, and purchase software to do it - vs. pulling the ECM and sending to Fernando.

The engine brakes are another issue.

 

Weak PACBRAKE on 1995 12.7 S60