2021 Ram 3500 H.O.

ShinerBock wrote:

4x4ord wrote:
Conversion kit for Cummins

I can’t imagine the labour being much on a Cummins. Apparently it doesn’t require tuning which makes me think this CP3 is modified to put out more pressure than the CP3 previously used on the Cummins.

It doesn't require tuning because it is not a stock CP3. It has a 10mm "strocker" camshaft which increases pressure over a stock CP3.

Something must be different. I don't know much about these fuel systems so I might be totally out to lunch but I thought even in stock form the CP3 puts out more volume than the CP4? Regardless, I thought it was the fuel control actuator (FCA) that let more fuel into the pump when the ECM called for more pressure. My understanding is that the CP3 did not have a pressure sensor capable of measuring 29000 psi. When ECM calls for higher rail pressure the FCA lets more fuel into the top of the pump, increasing the fuel delivery and pressure. The problem would occur when the sensor reaches it measuring limit. At that point the pressure continues to rise but because it's not measured the ECM keeps calling for more. It doesn't really matter how it works .... I hope Bosch is supplying Cummins with a high pressure CP3.... it would be even better if the Duramax and Powerstroke could get something as reliable. A CP3 conversion is available for the Duramax but not the Powerstroke ... too bad for us Ford guys.:(