ollie32

Hi there,

I have a 2003 Ram,

Just got my commander going to monitor rail pressure.

Just wondering what kind of readings I should be seeing for a stock engine. I am hovering anywhere from 4800 to 5300 at idle. I haven't been out on the highway yet to open it up.

Just curious what I should be looking for

Thanks

G

2007 5.9

I just got a commander, what else do I need to be able to read rail psi.?

tritont

you DON'T want see anymore than 25K psi @ WOT. You should expect to average between 18 & 24K while driving normally. The closer to 25K the better.

ohyeahfriday

So you are saying that high presusre is good, as long as it is under 25k?

tritont

well, I'm no expert, I can only go on what I'm told by those in the know and what I find out myself through research.

The relief valve is suppose to blow at around 28k. The rail itself is supposedly rated for a limit of up to 30K. Anything over that and you may have a bomb on your hands.

The closer to max pressure, the better the injectors will function in atomizing the fuel. Good fuel pump pressure and high rail pressure will help you avoid draining the rail if you get to that point in your mods.

Dodgezilla

My truck hits 26-27000psi with my current stack!!If I turn the Puck off then the max is 23500psi..... I idle at around 9000psi....

ollie32

Dodgezilla,

So when your Puck is off and you are getting 9000 is that with a stock lift pump?
My reading are a fare bit lower, flucuating between 4800 and 5400 and at 60 I'll top out at 15000ish. Wondering how accurate this box is or my pump might be weak.

Cheers

Dodgezilla

Yes, I have a stock LP but it does seem to keep better than average pressure. My pressure at idle is 10psi and drops to around 5psi on a WOT run. If I run the Puck along with the Predator on the settings where it adds pressure too then it drops down to 1-2psi. I removed the Predator today and installed the stock tune and I'm now at 7000psi at idle on the rail. Remember that I also have a manual trans so my idle may be a bit higher than yours if you have an auto. That may cause my idle rail pressure to be higher....

qzilla

03-04 trucks have significantly lower Rail Pressure at idle and less peak psi when stock.

I don't know how or why but, the 9000 psi seems to be the average for a 600 series truck with any downloader on it?? Seems odd to me.

I have lobbied and tried to get seperate forums for 03-04 trucks and 04.5-07 5.9L trucks because there are a lot of significant differences. It gets really confusing for some with the main issues being boost, rail pressure and dyno numbers. We are talking an 80hp spread from worst to best on the 03-06 trucks! That is stock!