My brother inlaw got a o4 Dodge truck 6spd and 5.9 Cummins. Is it possible to adjust the rail pressure release valve,or maybe do something with the pressure regulator on the cp3 pump ? Since some programmers bump up rail pressure I imagine the release valve is already higher than what the computer commands the high pressure pump to put out. I heard that unpluging the pressure regulator on the pump will make max pressure,but don't know if thats such a good idea. I would like to do a little something to give it more fuel,untill he can afford to buy a smarty. We are putting 6 inch stacks on it this weekend.
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04 Common Rail
- Thread starter 6.2 turbo
- Start date
- Staff
- #2
I don't think there is much you can do along those lines without putting it into limp mode. You can probably put a resistor inline with the rail pressure sensor and bump the pressure up some that way to get a bit more fuel, but don't know how well that will let it idle.
I have a OTC scanner,I might check the rail pressure ,if it gives me the psi. I did some research, and some people are modifying the FCA valve that controls fuel to the plungers,but maybe not that usefull,by itself. If I did a resistor I would need a mechanical gauge,as the scanner would read incorrect ,and too much it would dump rail psi out the release valve,probably need to adjust that also. There is also a internal supply pump pressure regulator set at 75 psi,that feeds the plungers,maybe I could adjust that,it might let more fuel through the FCA ? Looks like its right on top the pump, and looks similar to a P- pump return regulator,pressing the ball in farther will increase pressure. Could be that the computer would just override this ?
Cumminalong
Doghouse Diesel Performance
DO NOT DO ANY OF WHAT YOU ARE TALKING ABOUT!
The stock CP3 is capable of supporting a bit over 600 HP without significantly increasing the rail pressure. Rail pressure is the LAST thing you want to mess with to achieve power.
Stock, the ECM commands a max of 20K psi. The relief valve opens at 24K psi. The stock sensor can read a max of 26.6K psi. Injector damage happens ar around 28K psi.
Whatever you see on a RP gauge, there is usually a 1K - 2K psi spike above that.
The CP3 needs to have a supply pressure between 10 - 20 psi, 13 - 17 psi is ideal.
Pressure isn't the problem, volume is. BUT, not until you get up into that 600 HP range.
Example, I only run my truck at a max of 22K psi, but I run dual CP3's to supply the volume.
Do yourself a favor and call me before you get crazy on this thing. This isn't like tweaking a p-pump.
Here's what happens if you don't know what you're doing on that pump. This is a customers truck messed with his pump and didn't understand the implications.
Ask yourself this. Which is cheaper? $1000+ for a CP3 or less than $700 for a Smarty?
The stock CP3 is capable of supporting a bit over 600 HP without significantly increasing the rail pressure. Rail pressure is the LAST thing you want to mess with to achieve power.
Stock, the ECM commands a max of 20K psi. The relief valve opens at 24K psi. The stock sensor can read a max of 26.6K psi. Injector damage happens ar around 28K psi.
Whatever you see on a RP gauge, there is usually a 1K - 2K psi spike above that.
The CP3 needs to have a supply pressure between 10 - 20 psi, 13 - 17 psi is ideal.
Pressure isn't the problem, volume is. BUT, not until you get up into that 600 HP range.
Example, I only run my truck at a max of 22K psi, but I run dual CP3's to supply the volume.
Do yourself a favor and call me before you get crazy on this thing. This isn't like tweaking a p-pump.
Here's what happens if you don't know what you're doing on that pump. This is a customers truck messed with his pump and didn't understand the implications.
Ask yourself this. Which is cheaper? $1000+ for a CP3 or less than $700 for a Smarty?
Cumminalong
Doghouse Diesel Performance
This is what happens when you cap the rail or crank the pressure up too high.
This is a cracked injector body and nozzle.
As I said, rail pressure is the LAST thing you want to add to achieve power on a common rail.
You can see the crank in the fuel bore in the 5 o'clock position in the picture below.
You can see the discoloration in the fuel bore in the 5 o'clock postion which indicates a crack. What you can't see in this picture is the face of this nozzle is actually spider webbed. Much longer and the entire nozzle would have come apart and this would have meant rebuilding the motor and getting a new head.
Remember, you can build it cheap, powerful and reliable, BUT you only get 2 of those 3 at any one time.
This is a cracked injector body and nozzle.
As I said, rail pressure is the LAST thing you want to add to achieve power on a common rail.
You can see the crank in the fuel bore in the 5 o'clock position in the picture below.
You can see the discoloration in the fuel bore in the 5 o'clock postion which indicates a crack. What you can't see in this picture is the face of this nozzle is actually spider webbed. Much longer and the entire nozzle would have come apart and this would have meant rebuilding the motor and getting a new head.
Remember, you can build it cheap, powerful and reliable, BUT you only get 2 of those 3 at any one time.
Cumminalong
Doghouse Diesel Performance
The injector was too much rail pressure and it cracked the injector.
The pump was what happens when you turn up the low side pressure and it blows out the seal. This blows the plugs and destroys the pump internals.
If you don't have a test bench to calibrate the pump, you DO NOT want to mess with it.
If you want to cheaply modify the CP3, your best bet is what's called the "Bag of Parts".
https://stores.myregisteredsite.com...I&Product_Code=IISBOP&Category_Code=CP3+Dodge
This comes with the parts to up the volume of the pump by 15%.
The pump was what happens when you turn up the low side pressure and it blows out the seal. This blows the plugs and destroys the pump internals.
If you don't have a test bench to calibrate the pump, you DO NOT want to mess with it.
If you want to cheaply modify the CP3, your best bet is what's called the "Bag of Parts".
https://stores.myregisteredsite.com...I&Product_Code=IISBOP&Category_Code=CP3+Dodge
This comes with the parts to up the volume of the pump by 15%.
searstractorfan
New Member
I was cheap and Cuminalong told me what i really needed(hes smart lisen to him!!!) he sold me a smarty jr. its like $500, and got it almost next day!!!! It made a WORLD of difference!! I had the edge mileage max and it was ok, but this smarty jr WOW!!!! I can make black smoke ALL day in performance mode!! then in economy or tow mode its calm no smoke but lots of go still......My edge didnt do that...Is the 04 you got an 04 or an 04.5??? Ive got my edge to get rid of cause i will NOT use it again....I LOVE the smarty jr....I can even slip my clutch in performance mode!!!!! I DID NOTHING to my truck except install a K&N air filter, and the smarty, i still need to install my boost elbow to get more boost.... You might look into the smarty JR as a cost saver and talk to cumminalong, if you dont intend to build your truck(he can explain as he did to me!!!) this was the best way to go for me!!!
Cumminalong
Doghouse Diesel Performance
It's not that easy to just move the tone ring.
It's bolted and pinned behind the crank damper. You have to drill new holes in it. Moving the crank sensor isn't happening either, unless you do something like a Roktech.
Besides, 2 degrees isn't going to net you squat on a common rail. Electronically, you can add up to 9 degrees of timing.
Seriously man, as easy as these things are to tweak electronically you're crazy to mess with some of the stuff you're wanting to. You're treating it like a 12V.
I work on these things every day man, trust me on this.
Cumminalong
Doghouse Diesel Performance
I hate to say it, and don't take this the wrong way, but I think a lot of it is in the owners head.
You can pull the crank sensor off and the truck runs just fine, it just throws a code. The only thing it does is send the signal for the tach and acts as the primary sensor to the ECM for engine speed.
The actual timing is done via the cam sensor, behind the injection pump, which is the primary sensor for timing and is the secondary sensor for engine speed. Unplug that an the truck won't start.
The only thing you did by sanding down the tone ring is tell the computer that the engine is running slower than it is, which can cause it to bump the actual engine speed up to put the idle within the correct parameters. Opening the gap in the tone ring simply increases the amount of time that the sensor goes from 0 to 5 volts, which tell the ECM the engines speed.
Again, don't take this the wrong way, but it's not a 12V. There are better ways to do it.
With the push of a button, timing goes up or down.....boost goes up or down.....power goes up or down.
You can pull the crank sensor off and the truck runs just fine, it just throws a code. The only thing it does is send the signal for the tach and acts as the primary sensor to the ECM for engine speed.
The actual timing is done via the cam sensor, behind the injection pump, which is the primary sensor for timing and is the secondary sensor for engine speed. Unplug that an the truck won't start.
The only thing you did by sanding down the tone ring is tell the computer that the engine is running slower than it is, which can cause it to bump the actual engine speed up to put the idle within the correct parameters. Opening the gap in the tone ring simply increases the amount of time that the sensor goes from 0 to 5 volts, which tell the ECM the engines speed.
Again, don't take this the wrong way, but it's not a 12V. There are better ways to do it.
With the push of a button, timing goes up or down.....boost goes up or down.....power goes up or down.
Cumminalong
Doghouse Diesel Performance
If he wants to get decent mileage out of it, just have him get a Smarty Jr and call it a day.
Set it on the 60 - 70 HP tune, bump up the timing and that's as good as you'll get without swapping cams.
Set it on the 60 - 70 HP tune, bump up the timing and that's as good as you'll get without swapping cams.
We installed a Smarty S-06 POD . He ran it like that for a while,ran great. We recently downloaded the REVO TNT. With it on number 9 and timing set on defaut #0 torque set on #3 or #4 it pops /cuts out at about 3000 rpms on a quick rev only. I tried all the timing settings,works best on #0. Only tried #3 and #4 torque. I checked the rail pressure ,its from 16000 psi and 18000 psi when popping. With the rail pressure set on #4 it only peaked at 27000 psi ,if wound out to the top of 4th.
Cumminalong
Doghouse Diesel Performance
You really are gonna destroy that truck.
TNT is for heavily modded trucks, not daily drivers with stock fuel systems.
Put it back on the Revo tune and don't set it higher than 70 HP if he still has a stock trans and torque converter / 90 hp if it's a manual.
Level 9 on the TNT program is a 230 HP tune......you're popping because you're running the rail dry and cavitating the fuel rail.
Do you not see in the instructions where it say DO NOT run rail pressure on #4 as i may damage the fuel system.........
Torque management of 3 or 4 with a stock trans?......he'll be rebuilding that trans in short order.
27K psi......that's because you're seeing the max that the rail pressure can see. 26,600 psi is all it can see. It's based on a 5V signal and 5V is 26,600 psi. Anything beyond that, you'll never know. Rail pressure spikes between 1 - 3K psi when you get off the throttle.
Even on my truck with dual CP3's, dual feed lines, and stainless injector bodies, I don't set the rail pressure over 2. That puts me at about 23,000 psi at WOT. On a stock rail, you blow the relief valve at ~24,400. Due that a few times and it'll fail.
You have been warned.
TNT is for heavily modded trucks, not daily drivers with stock fuel systems.
Put it back on the Revo tune and don't set it higher than 70 HP if he still has a stock trans and torque converter / 90 hp if it's a manual.
Level 9 on the TNT program is a 230 HP tune......you're popping because you're running the rail dry and cavitating the fuel rail.
Do you not see in the instructions where it say DO NOT run rail pressure on #4 as i may damage the fuel system.........
Torque management of 3 or 4 with a stock trans?......he'll be rebuilding that trans in short order.
27K psi......that's because you're seeing the max that the rail pressure can see. 26,600 psi is all it can see. It's based on a 5V signal and 5V is 26,600 psi. Anything beyond that, you'll never know. Rail pressure spikes between 1 - 3K psi when you get off the throttle.
Even on my truck with dual CP3's, dual feed lines, and stainless injector bodies, I don't set the rail pressure over 2. That puts me at about 23,000 psi at WOT. On a stock rail, you blow the relief valve at ~24,400. Due that a few times and it'll fail.
You have been warned.
He has a 6spd with a Valair twin disc. Not sure if the rail is dry at 18000 psi,could be air bubbles. It still has the intank lift pump and no fuel pressure gauge,so its probably at 0 when it pops. Only reason for trying the #4 pressure was because it was popping. I did install a pyrometer and boost gauge. I plan on turning back the power untill it's right on the verge of popping. In the future we will mess with the lift pump,and the cp3 if needed,and install a fuel pressure gauge. Is 12 psi considered max safe lift pump pressure or can you go up to 15 or 20 psi ?
6.2 turbo....
Do yourself a favor and listen to Cumminalong. Of all of the forums I've been on, this cat is one of the most knowledgeable of them all and he goes through the trouble of taking and posting great pictures of what he is talking about. You want to save money and get power without breaking something? Listen up.
Do yourself a favor and listen to Cumminalong. Of all of the forums I've been on, this cat is one of the most knowledgeable of them all and he goes through the trouble of taking and posting great pictures of what he is talking about. You want to save money and get power without breaking something? Listen up.