I have had some issues with my dipricol rail gauge and i have decided I need something that reads rail pressure from the ECM not the rail sensor, which should be accurate if you aren't running a pressure box. What stand alone guage or combo of gauges (like the quadzilla) do you all like for rail pressure, any recommendations? Thanks, Jay

 

I thought Quad was doing something for Rail Pressure with the Recon Platform. Haven't heard anything for awhile.

 

We actually got a final proof for the overlays in today. I believe wiring harnesses are due in next week sometime.

When that is done you can have a Rail Pressure only gauge or a Rail Pressure/Lift Pump pressure gauge if you want?

Beyond that the Commander will also work just fine. You can use either of them with a pressure box as well and they will still be accurate.

 

Hey quad, where does this read the rail pressure from? Because my dipricol gauge is reading from the rail sensor and isn't in accordance with what the drb3 says. Jay

 

There are 2 trains of thoughts on that.

We are going to read directly from the rail pressure sensor. That is the only way to reliably read it. That is the way the ECM reads it as well.

The DRB is reading off of either the OBD2 bus or the Chrysler SCI data bus. Either way the info on a scan tool is sort of second hand. The raw data goes to the ECM and the ECM then filters it. The Scan Tool/DRB then goes online and has to send a request to receive a data message. the ECM sees this and responds with the correct data, the tool then decodes it and shows it to you.

To your eyes it seems fast, in the world of ECm's, micro controllers and gauges it is slow as a dog! If you have a pressure enhancing module of any sorts, plug in or a downloader then the DRB info will be flat out wrong. If not then it should just be slow.

Now, there have been some issues with the Di-pricol gauge itself. remember some one ( a human) has to calibrate these gauges. I do not believe that the calibration is wrong due to the fact that I know who put it together and I think a lot of what he is capable of doing.

I think the problem lies in the stepper motors and or the other internal parts of the pricol gauges. I have heard and seen the same things with their pyros in some instances. These motors tend to build a memory and they cause the motor to not be able to sweep properly. I am not sure what the exact problem is as I am not a stepper motor expert but, this does appear to be a known problem.

The last thing I would ask it, how wrong is the Di=pricol gauge? The best you should be able to tell on the Dipricol gauge is 100 psi. Anything less than that is a guess. I am betting the accuracy is more in the 200psi range because of the motor and needle setup. The DRB is probably accurate although tardy to the tune of about 10 psi or so. The CP3 pulses pretty badly trying to remain stable and I doubt that the analog gauge can respond quickly enough to show you this.

 

My dipricol was thousands of #'s of without the pressure box on the truck. It also seems like the dipricol interferes with the signal somehow as before I last took it off it made my truck run like crap. I've heard of many others with the same problems, mainly after a modified CP3 is added.

 

Where is the TST reading it from...you would think it would be direct from the sensor as they are also using this signal to add rail pressure? ks

 

I haven't heard of many other CTDs having trouble with the RP gauges after CP3 mods...

Since the DiProcol harness adds a short length of wire to that sensor bus, the signal could be slighty attenuated - but I doubt it would be significant.

Like Quad posted, 100-200psi variance on a gauge that reads in thousands is hardly visible.

Besides, analogs are great for viewing trends on the fly - not capturing exact values at a particular moment.

 

If you run a pressure box then anything you read past that harness will be fooled pressure and can't be compared to anything. The only true reading for rail pressure with a pressure box would be at the rail sensor with the gauge plugged into the sensor first and then the pressure box and then the stock harness. The commanded pressure and the actual (rail pressure sensor) will differ because of the pressure box at that point. Normally a code would be set but the pressure box keeps that from happening. I can't see where a pressure gauge would interfere with a modded CP3 or vice versa but....the ratio of trucks with modded CP3's running a rail pressure gauge is likely higher than stock trucks running rail pressure gauges so it might just be the odds.

 

That's why the DiPricol plugs into the sensor, followed by the fueling box (if applicable)

 

After my problems John at Floor-its told me of 4 others that have had the same problem. I think Omaha Ram, Big Mak, can't think of the other and myself. All were great without a modified CP3. It doesn't make sense to me what the difference is, but get in my truck and you can tell a difference.

 

My truck runs like a raped ape so everything is working right. I am sending the dipricol off today for a replacement and if that doesn't fix it I will be looking at something else. Jay