What is normal to see for RP going down the highway at 70-75+? I want to get some feedback from other bombers to make sure my Rail Pressure gauge is working properly and that im not causing damage somewhere. Mine hovers around 20K psi normally.

Is 20K psi to much? Am I hurting my stocker injectors at that pressure all the time?

I have tried running my MP-8 on various settings but my Smarty is always on 9. My truck just seems to run it's best with the MP8 at 100 percent. I don't beat on the truck but it's nice having the power at my foot peddle when/if I need it.

EGTs run between 650-750 degrees. Boost is around 6 or 7psi most of the time FWIW. Thanks!

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@ a 75mph cruise with beta 4.4 my truck runs right around 20k...seems normal to me?

 

No it is not all right, this topic has been beat to death over and over. 20k cruizing on the freeway is not good on injectors and even Don himself cruizing around at 20k plus will destroy a injector. Here is the thread in which I am refering too https://www.dieseltruckresource.com/...d.php?t=198317.

 

I would turn that pressure box off just cruizing around, which program do you have o the smarty some all ready add rail pressure. SO you are even throwing more pressure into the mix. I cruize at about 16,000-17,000 at 65-70mph.

 

Well here is another one I have to agree with you on too Kman. My gauge reads between 15,500 and 17,800 at 70 mph, and if you hook a DRB(Chrysler Diagnostic Computer for 03-06 DRs) up to my truck it reads right along with my after market gauge. Working on as many stock truck as I have and reading their pressure readings you usually see a reading anywhere between 13-17,00 at cruising speed and a max of 22,500 at WOT. This is typically what i would see no matter if it was an 03-04, or an 04.5-07 5.9L or an 07-08 6.7L. So like I said I would have to agree with Kman on this subject.

 

Smt3V312DD311B.Smt This is the Smarty program version at the current time. I haven't switched to the REVO yet. I love the way my truck runs right now and im reluctant to make a change (so smooth). It runs like a scalded ape as is. I guess if im killing my injectors then I will have to turn down the MP8. But, I just hate to do that because the truck runs so good and seems to get better mileage.

I don't like to fool around with settings etc. It is just in my nature to find what and how I like to run it and leave it alone. In fact I have noticed when I do turn down the MP8 it didn't seem to make any difference in the RP.

I appreciate the link to the thread...........good reading and lots of great info from Don. But not good news for me because i don't want to lose my mileage gain or awesome, smooth, performance for dd or playing.

I want my cake and I want to eat it too.

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Switch to the REVO software and run setting 2 on the rail pressure. I think you'll like it just fine.

 

ah bummer...

I've been running Revo on wild RP... guess it's time to back it down and get an MP8 for when I want to play

good thread. everyone I asked about what was safe said I was fine. I even emailed Don about it, but I guess I wasn't clear about just how high I was seeing at cruise.

 

hmm interesting...I am going to pull my Smarty off today and see what my stock program cruises at....my truck(G56) is pretty rapped out when I get up to a 75+mph cruise....I wounder if my trans low gearing has any thing to do with it? There are guys in that other thread who have trucks that DO cruise 20k with stock programing..... and Don never responded about it.....so what now?????

 

very interested in this as I've got an extended crank condition while hot, and I'm looking at tearing into the injectors and connector tubes to see if I can get rid of it. I don't want to cause the problem again with extended higher RP if that's what caused it in the first place!

 

My 1st post in a while here because I've been busy dealing with a cracked injector due to what I believe was high rp. Ive been drivin my truck for 3 years and last month I drove 3 hrs at 70mph with RP at 21.5k. next day.... starts to pop at high rpms on certain levels with white smoke. Went through 3 programs thinking that was the problem. finally.....2 weeks ago, shaking, white smoke 100yds and oil level 4 gallons too much full of fuel... cracked # 2.....Stay away from high Rp when not needed. Im a believer now

 

Well yesterday late afternoon and tonight coming home from work I did a little test to see where my RP was at running with the MP-8 at Zero percent and at 100 percent. The difference was almost non-existent.

My RP ran between 17.5k and 20k cruising 75ish either way. So either my gauge isn't working? or the MP-8 doesn't raise it much or any? Or the Smarty tune im running must already increase the RP?

Any ideas? I just know I love how my truck runs with it on. Im still on the original stock sticks for now at 92,500 miles. Hopefully some flux sticks are in my future, but I want them to be because I want them and not due to an avoidable problem.

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that was a very informative thread. i had been seeing around 20,00psi with TNT rp3 while cruising. i'm happy i read that, i changed to rp2 and that put me right in the paramaters that don m had mentioned

 

Pressure is bad every day. Adjust it down or pay the piper so to speak. I keep mine off most of the time. On Quad X2 Std. 1 or 2 pressure tune I am still O.K. Right at 18,000psi cruising down the road. I just prefer not to use it. Quad boxes actually are perty good about not being to high a pressure just cruising down the road by themselves.

 

My mp8 makes a big difference. Now, I guess I can't say that I've run Smarty on RP#4 and then played with the mp8 to see if it changed it at all. I run the Smarty on RP#2 and then if I'm gonna play I turn the mp8 up.