Im working on a buddies truck. Im a peterbilt CAt guy and know My way around Cats only. I know nothing about Macks so I need your help. I have driven plenty of MAck rd trucks that i believe were e7 350's. They had plenty of power down low for what they were as i remeber pulling 23 ton payloads.
The truck im dealing with is a 2000 mack rd triaxle dump with e7 400 motor in it. I drove it empty and it is indeed no power. No Boost gauge in truck but working on that. Put a load in that truck and its not going anywhere off the line. Heres the biggest thing that is the issue. The previous owner put a S400 turbo on it. Mack part number 631gc5173amx. According to the previous owner, MAck dealer installed it a few years back. I called local mack with vin. Truck came with from the factory an s300 part number 631gc5174amx. Borg warner cross reference to 174822.
With that being said, no stage 2 injectors or tune was done with this. Would this s400 make this much lag and no power without supporting mods? And will the s300 wake this truck back from the dead on the low end? I have seen this on Cats before. Where the nimrod would slap a bigger turbo on thinking its gonna do anything but make life hell without supporting mods. Complete dog. Like i said, i know NOTHING about macks and thats why im hear. Dont want to assume ANYTHING and cost someone money. Yes i did pressure test on the system to check for leaks anywhere going into the cac and motor. Fuel filters done etc, Turbo spins freely and all good
