cummins vs. psd

[TxPSD9673]

not to hijack but i did the fpr shim and as you said my idle rpms' bounce around by like 75 up and down, not smooth idk if its the mod or somethin else makin it do that

[gtspowerstroke]

On my truck I was fighting a nasty rolling idle that would a lot of times kill the engine when I'd roll to a stop. I had the pressure set at about 60 psi or so. Once I discovered that when my fuel pressure was lower the idle was as smooth as every I set my FPR so that it runs about 38 psi at idle and used the boost compensating port to raise the pressure to about 60 psi max as the boost comes up. I found that on the dyno if I ran my pressure to 80 psi I actually lost 10 or so hp. I do have a completely new fuel system with an Aeromotive FPR and pump. So you can't run the stock FPR like I have mine set up with the boost. Just giving my experience with the higher fuel pressures.

[pipelayerjdh]

On the first gen cummins, you are in about the same boat as first gen psd's. You can turn the fuel up on the cummins, but you will probably only see about 200 wheel HP. That's about the same as an OBS PSD with a tuner or chip. Both will need intake and exhaust.