Cummins/82 C10

[cmann250]

Hold the phone! Ellis is turning something up? Didn't you learn last time?

FYI, I made stock-ish Durmaxes my itch-bay once I had a sturdy transmission. You can out run them at about 300 horse if they have the usual intake/exhaust/cheap tuner. EFI live is bad news though

[ellis93]

Hold the phone! Ellis is turning something up? Didn't you learn last time?

:

This is different,it's not a vehicle I need to have functional 100% of the time.

[ellis93]

Got to fiddling around making a pressure test port there on my filter housing and got to test the supply pressure to the injection pump......9 whole pounds No wonder it's been feeling lax in the power department

Did a Google seqrch and seen where 20 or 25lbs was stock and where some were running upwards of 60 pounds on the 160hp pump,which is what mine is. Folks running that pressure said that it allowed more barrel fill quicker to make up for the short profile of the pumps cam.
Anyone have first hand knowledge of this?

I don't want fuel puking out into my crankcase over some bs info.


For the time being I pulled the overflow valve and shimmed it to where the pump is seeing 35psi.

[PToombs]

A p-pump shouldn't puke fuel into the base like a VE, the fuel is in the top of the pump and the bottom is lubed with oil. I don't wanna say it can't happen, but the pumps are way different than ours.

[ellis93]

So,probably would be a plus to run a little higher psi then?

[PToombs]

Yeahhhhhh, maybe. I don't know if I'd run 60psi, but 35 for sure. I'm not up on all that hotrod p-pump stuff. I can grind a mean "bury your pyro" plate though!

[dazedandconfused]

45psi is what most P pump guys I know run on the street. The little 160 pumps seem to do well at higher pressure. 95 junker drag truck thread on Comp D has a lot of cheap mods listed. Big blue has done a lot with it.

[ellis93]

Yeahhhhhh, maybe. I don't know if I'd run 60psi, but 35 for sure. I'm not up on all that hotrod p-pump stuff. I can grind a mean "bury your pyro" plate though!

Yeah I've done a little research into that myself

[ellis93]

45psi is what most P pump guys I know run on the street. The little 160 pumps seem to do well at higher pressure. 95 junker drag truck thread on Comp D has a lot of cheap mods listed. Big blue has done a lot with it.

I believe one of the post I was reading had him comment on it Andy. He said,iirc, that after 45 he seen little to no gain. I'll have to look at some of his treads.

[dazedandconfused]

I know he is running more then that now since he has done more pump mods.

[RCCUMMINS89]

PSI depends on the setup of course............But I'd run 35 to it for starters.

[DMan1198]

The lift pump that's going on The Roo Hunter is made to do 70psi, but that's going to be feeding a 13mm p pump

[ellis93]

I know he is running more then that now since he has done more pump mods.

Yeah he hinted at looking into it and apparently I misread his post

I honestly think pressure is one of those things related to overall tuning. Pressure vs horsepower will change from pump to pump. Based purely on my testing with my 160 pump, (which has a cam design that is most likely to benefit from higher pressure), HP increased tremendously going from 35 psi to 65 psi. HP increased an average of 83 HP throughout a 1/4 mile pass. The biggest seat of the pants difference is in the 2500 RPM+ range. I am currently working on yet another switchable lift pump to test power gains in the 75-85 psi range to see if power continues to increase with added lift pump pressure on this 160 pump.

On my 98' daily driver with 180 pump, I experienced a mild 25 HP increase going from the stock pressure that fell 25 to 15 psi at WOT to a modified stock setup that falls from 45 to 35 psi at WOT. I have a feeling that with further testing, HP gains will cease once it maintains 45-50 psi WOT. The 180 pump's cam design allows for a lot more fill time than a 160 pump.
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I figure that I'll be served best by leaving it as is for now,then go nuts later.

[ellis93]

Made some progress on the dash pod






That's the basic shape I'm after,I just smeared a little bondo on it to smooth it out. Tomorrow I sand and see what's up

[PToombs]

Be careful! If you make it too nice that could turn into a full time job!