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Thread: Rail Pressure tuning help?

  1. #1
    Lifetime Member AdamRRT's Avatar
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    Default Rail Pressure tuning help?

    Ok I have really no idea what is preferred for pressure tuning. That is as it applies to a daily driver. I have a theory of how I'd like the process to work. I'd prefer to keep stock rail pressure across the board. That way I minimize injector wear. Then at WOT of course crank it up as much as it makes power yet still cap it safely around 25,500psi.

    But I know almost nothing about tuning rail pressure for power and for mpg.

    All I really know about pressure is:
    1 it makes the truck a blast to drive
    2 it doesn't help my mpg. That's a marketing ploy IMHO. I believe we are already above the pressure at which we get optimal atomization. At least that is based upon multiple tanks of fuel at differing pressure settings. Yes despite the theory. I'm aware.

    Anybody care to share a little info on what you've found to work best for a daily driver? No trade secrets. Just some basics. Thanks in advance. I appreciate the info.
    2006 Mega 2500. EFI Live, ex-Smarty Retardie, XZII, HTS trans, Edge TC, GM gov sol, AirDog II, Quadzilla intake, muffler, -cat, 35's on 18's, 4" lift, E.D. 62/68/12, 70 hp tips.
    Every ball player use a ton of steroids, every vehicle should have a big shot of nitrous, and every woman should have big fake tits. If it's available, use it. And don't whine when someone else does.

  2. #2
    Lifetime Member 2007 5.9's Avatar
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    I run pressures for DD close to what a 03-04 CR operates at.

    70mph@2000rpm 15,000psi

    My graphs are smooth and linear from my 5500psi idle to 23,500 peak.

    I don't run pressure over stock peak.
    Les Szmidt
    2007 5.9 Dodge Ram
    2014 Ram 3500 Aisin tuning Emissions Equipped
    EFI Live Cummins BETA Tester
    Silver Bullet Tuning
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  3. #3
    Lifetime Member AdamRRT's Avatar
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    Thanks Les.
    2006 Mega 2500. EFI Live, ex-Smarty Retardie, XZII, HTS trans, Edge TC, GM gov sol, AirDog II, Quadzilla intake, muffler, -cat, 35's on 18's, 4" lift, E.D. 62/68/12, 70 hp tips.
    Every ball player use a ton of steroids, every vehicle should have a big shot of nitrous, and every woman should have big fake tits. If it's available, use it. And don't whine when someone else does.

  4. #4
    Junior Member CIDRAUGHN's Avatar
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    Ive been finding that with larger nozzles (mine are in the 110% range) that a slightly higher RP results in a bit cleaner burn. Now Im not nearly as far along in the learning curve as you all, but thats just what Ive found so far. In the cruising range, im running 19k ish rail, with a smooth increase all the way up to a WOT RP of around 25K. That has helped get rid of much of my cruising haze. Also, making a pretty fast smooth ramp up to cruising RP from acceleration has helped clear out some smoke issues.
    06 Dodge RCLB 2500 5.9L Hamilton, Maxxspool, Wicked Diesels, Bullseye Power, Industrial Injection, South Bend Clutch, Amsoil, K&N, ARP,EFILive, T&C Diesel, ATS, GDP...

  5. #5
    Lifetime Member killerbee's Avatar
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    Quote Originally Posted by AdamRRT View Post
    All I really know about pressure is:
    1 it makes the truck a blast to drive
    2 it doesn't help my mpg. That's a marketing ploy IMHO. I believe we are already above the pressure at which we get optimal atomization. At least that is based upon multiple tanks of fuel at differing pressure settings. Yes despite the theory. I'm aware.

    Anybody care to share a little info on what you've found to work best for a daily driver? No trade secrets. Just some basics. Thanks in advance. I appreciate the info.
    High rail pressure is parasitic. That is the first thing to accept. No free lunch. So use only enough pressure to meet your torque and power needs. Steady empty cruise requires only 25-35 HP, so minimal pressure is required to keep pulse manageable in duration.

    etc.
    Michael, Systems Engineer 04.5 D-max LLY, Phoenix, Arizona Email
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  6. #6
    Lifetime Member AdamRRT's Avatar
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    Codraughn: thanks man. Makes perfect sense in bigger injectors. Just the relation of the fluid dynamics.

    Killerbee: thanks man. Pretty much as I thought. But I had no clue about cruise settings. Thanks.
    Last edited by AdamRRT; October 22nd, 2011 at 07:07 AM.
    2006 Mega 2500. EFI Live, ex-Smarty Retardie, XZII, HTS trans, Edge TC, GM gov sol, AirDog II, Quadzilla intake, muffler, -cat, 35's on 18's, 4" lift, E.D. 62/68/12, 70 hp tips.
    Every ball player use a ton of steroids, every vehicle should have a big shot of nitrous, and every woman should have big fake tits. If it's available, use it. And don't whine when someone else does.

  7. #7
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    I'm playing with rail pressure some and minimizing wear is part of my goal. My thought is to find the minimally effective pressure, keep the curves smooth and nothing more than stock. Right now I have a tune that is running about 17-18k at cruising speed and kinda flattens out there until the commanded fuel gets up. That way the pressure doesn't change too much with the usual accelerations of highway driving.
    06,QC,4X4-ARE top, Bedslide ,EFILive tuned my me and Anarchy, FASS, DTT, ATS 5000 twins, PDR cam, BD IC, Carli/Thuren, Warn Air/Winch, F1 Springs, Studs
    01,QC,4X4-Banks PowerPack, RV275s,PDR35/14, FASS, Carli/Thuren/Lorenz, OnBoard Air, DTT, ARB/Warn

  8. #8
    Lifetime Member 2007 5.9's Avatar
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    I have actually bumped mine up slightly at cruising speed to aid in some little hazing i have left ....so far its proving to be helpful in eliminating that last little bit of cruising smoke.
    Les Szmidt
    2007 5.9 Dodge Ram
    2014 Ram 3500 Aisin tuning Emissions Equipped
    EFI Live Cummins BETA Tester
    Silver Bullet Tuning
    silverbullettuning@gmail.com
    www.youtube.com/ljszmidt
    http://www.facebook.com/SilverBulletTuninig

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