Dropping rail with 3 CP3s?

05_LLY

Out-A-Time
Aug 7, 2006
1,756
1
36
42
Norvelt, PA
Had a lbz truck do similer was only a twin cP3 truck though but only 100% inj..ended up being a bad/wrong controller. It was a wcfab controller. I believe it was made by fish at the time. I put that controller on a lly truck and worked perfecton that truck
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Last edited:

DPC

Member
Jan 2, 2012
323
1
18
Adams, TN
Change your scaling to this

1800.000000
1648.500000
1488.750000
1326.750000
1215.750000
1159.000000
1121.500000
1088.000000
1056.000000
1020.000000
1000.000000
993.000000
986.000000
930.000000
878.000000
826.000000
770.000000
000.000000
000.000000


Then go to table B1009 and set to "0" as well.

That will force the regulators to go wide open, essentially no real control over the CP3's/CP4's so you should get the max rail psi out of it.

They also have a set of billet rails now, supposedly flow way more fuel and uses LLY #2 and #6 Injector lines and have a larger cross flow rail between both banks IIRC.

Good Luck

If I do this will the desired pressure stop when it reaches commanded or will it keep on going?? It's an LB7 so the fuel pressure sensor will only read to 180mpa. Thanks.
 

CaptPhil

Active member
Sep 10, 2011
1,012
0
36
Delaware
If I do this will the desired pressure stop when it reaches commanded or will it keep on going?? It's an LB7 so the fuel pressure sensor will only read to 180mpa. Thanks.
It depends if you are commanding over 180mpa. If you are then the rail will keep going and you won't know how high, but you will make some serious power. If you are commanding 175mpa or so it will go as open as it has to in order to make the desired pressure.
 

DPC

Member
Jan 2, 2012
323
1
18
Adams, TN
I'm commanding 179 and my max rail is set to 180, I think it's time to upgrade the rail psi sensor so I know for sure what's going on.


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IOWA LLY

Yes, its really me
Feb 23, 2007
2,275
4
0
I've seen over 240 MPA on LLY injectors and never damaged them. This was a competition application but still, it saw those pressures for 2 seasons with no ill effects.

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DPC

Member
Jan 2, 2012
323
1
18
Adams, TN
I've seen over 240 MPA on LLY injectors and never damaged them. This was a competition application but still, it saw those pressures for 2 seasons with no ill effects.

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240mpa! That's about 35K correct?!
 

x MadMAX DIESEL

<<<< No Horsepower
Dec 30, 2008
7,535
1
38
34
Lexington, Ky
Y'all are lucky you can scale the lly and less to read higher pressure? We can't with an lbz. I'd like to run higher but don't have any way of knowing real psi (or the Ecm knowing rather)


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