Dual CP3's and lift pump supply pressure...

W

wespruett

Cummins Fanatic
Joined
Apr 20, 2009
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Is there an optimal Lift Pump supply pressure (or pressure range) for dual CP3's utilizing stock Dodge and DMAX pumps?
 
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depends on who's controller you're using. ATS allows for more than PPE's. Don't know of any others but, that's what determines the psi they need to see.
 
My AD150 is supplying 15-16.

I guess it's not intuitive to me why duals like to see a lower psi than singles. Please explain.
 
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I don't accept the premise that twin CP3s require less inlet pressure than a single... 10-20psi at the internal gerotor lift pump is ideal.
 
triton said:
depends on who's controller you're using. ATS allows for more than PPE's. Don't know of any others but, that's what determines the psi they need to see.
Click to expand...

I just recently tried both my PPE and a brand new ATS controller back to back...It didn't make Any Difference at all with my cold start / cold engine loping issue..

Didn't matter if I used 15 psi or down to 8-10...
 
Big Swole said:
I just recently tried both my PPE and a brand new ATS controller back to back...It didn't make Any Difference at all with my cold start / cold engine loping issue..

Didn't matter if I used 15 psi or down to 8-10...
Click to expand...

If I put my psi any where near 15 the truck doesn't even want to run. It spits & sputters as if injectors have gone bad. Dan@PPE is right in that their system doesn't want/need high psi. ATS on the other hand will allow much higher psi. I guess maybe PPE works off the premise that the Dmax pump doesn't need a LP and the stock Cummins pump runs off of 8 to 10psi from the factory..... idunno
 
Running 15-20psi from my ad2 will result in a cold idle p1012 fp too high code and idle between 7-9krp. Once its warmed up then all is golden until I go 70+% throttle which results in a 21-29k rail surge like a yo yo. Bad enough to even murder spool and bark my turbo.
 
On a buddy's truck we had to set the return pressure around 8 to keep the idle rail pressure under control. Anything more and the idle RP soared uncontrollably.
 
Here's a prime example of rail surge and the ecm not knowing what to do.
player.swf


Rail is the second number from the top on the left. Less than 150* coolant temp and _raising from stop sign to stop sign. Watch particularly the surge below 1k rpm.
 
What are you seeing at wot Wes?(I just figured out my field supply issues and damn she runs better)
 
I have ran 20+psi on dmax pumps in the past and as of last night both our race trucks now have dual kits with dmax pumps. On both, supply is 21psi. No problems at all. I have seen a few dmax pumps that didnt like over 12. But I dont understand why some do and some dont.
 
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