1. Welcome to PlowSite. Notice a fresh look and new features? It’s now easier to share photos and videos, find popular topics fast, and enjoy expanded user profiles. If you have any questions, click HELP at the top or bottom of any page, or send an email to help@plowsite.com. We welcome your feedback.

    Dismiss Notice

more power out of fl70 with cummins

Discussion in 'Truck & Equipment Repair' started by grosser397, Nov 2, 2013.

  1. grosser397

    grosser397 Senior Member
    Messages: 196

    hey guys i just bought a new freightliner fl70 dump truck with a 5.9 cummins 12v and eaton fuller 6 speed manual. the truck has air brakes and glad hands out the back so im hopping to buy a air break deck over but i feel a little extra horse power would be nice
     
  2. snowpro44

    snowpro44 Member
    Messages: 45

    take it too cummins!!dont buy aftermaket junk...let a good cummins guy tune it!!might need overhead,injectors set up!!should need more power..cant be tuned right.
     
  3. 90plow

    90plow Senior Member
    Messages: 737

    Your goi g to have a hard time. Thats a small motor in a big truck if you turn it up youll lose reliability. Hp isnt the key its torque my mack has 275 hp but 1,100 ftlb of torque.
     
  4. Mark Oomkes

    Mark Oomkes PlowSite Fanatic
    Messages: 10,868

    You don't know much about the 5.9, do you?

    Where's JDip when you need him?

    There's a million things that can be done to get more power\torque out of the 5.9, just depends on how mulch you want to spend. Fuel plate for starters. Injectors, turbos, cams etc.

    I went with a Stage 3 cam in my F350 and turbo lag is gone. Completely. Nada. Zip. Zero.
     
    Last edited: Nov 4, 2013
  5. Dogplow Dodge

    Dogplow Dodge 2000 Club Member
    from NJ
    Messages: 2,981

    Is it a P-pumped motor, or VE ?


    Either way, you can do the mods yourself. The VE is the easier of the two to work on, and power increases can be as simple as increasing the power screw, smoke screw, advancing the timing, etc. If you want even more power, it can easily be had with injectors and such. one of the easier upgrades is changing out the turbo to a more efficient unit with a smaller diameter turbine housing.

    Since your truck is in a heavier vehicle, you may wish to consult with the guys on DTR to see where to take this..

    http://www.dieseltruckresource.com/dev/
     
  6. grosser397

    grosser397 Senior Member
    Messages: 196

    I know a fair share as far as turning up the pump goes and bigger injectors that stuff but like some one said I don't want to effect the reliability of the truck , the nice part about this truck it's really easy on fuel when your just spreading salt.
     
  7. Mark Oomkes

    Mark Oomkes PlowSite Fanatic
    Messages: 10,868

    If 5.9's are unreliable after modding, there are going to be thousands and maybe millions of surprised as well as pissed off 5.9 owners.
     
  8. grosser397

    grosser397 Senior Member
    Messages: 196

    I know there reliable in a pick up but in a medium duty application you could over work the small motor
     
  9. Mark Oomkes

    Mark Oomkes PlowSite Fanatic
    Messages: 10,868

    The 5.9 is a medium duty diesel. The only true medium duty diesel in a pickup.
     
  10. 1olddogtwo

    1olddogtwo PlowSite Fanatic
    Messages: 11,531

    The C is a workhorse. Mark is 100% right. Ford even offers them in the larger F series.
     
  11. grosser397

    grosser397 Senior Member
    Messages: 196

    I suppose your right! I had a 06 5.9 dodge I just got rid of I but I am a big C fan when it comes to diesels!
     
  12. 90plow

    90plow Senior Member
    Messages: 737

    I've had three cummins. I also had a cat in an f 650 no matter how you look at it its only 5.9 liters its a small motor for a big truck. Turn it up all you want in a pickup they dont see the weight and rpms a med duty truck will. I know you can turn them up its still small displacement motor.
     
  13. 2COR517

    2COR517 PlowSite Fanatic
    Messages: 7,115

    Which one of those numbers gets you up the hill fully loaded?
     
  14. 2COR517

    2COR517 PlowSite Fanatic
    Messages: 7,115

    A 5.9 turns faster in a Med duty than a Light duty?
     
  15. 90plow

    90plow Senior Member
    Messages: 737

    No but in a med duty truck your rpms remain higher due to gearing and load (in most situations) When your on the highway pulling a load that engine will be near red line for hours trying to maintain speed. Im not trying to start a war i tried to turn up my small cat which was a 7.2 liter and the three dealers i approached warned against it for those reasons. You can do whatever you want but ive been warned against it just passing on the same advice. Some people are way to touchy and closed to other opinions. Notice how many fail to mention along with engine upgrades etc transmissions need to follow suite. Go turn up your dodge see how long the trans lasts same applies to med duty trucks. Many medium duty trucks will have lower hp ratings than their pickup counter parts just for the reasons i listed above. Flame suit on.
     
    Last edited: Nov 4, 2013
  16. 2COR517

    2COR517 PlowSite Fanatic
    Messages: 7,115

    So you didn't actually experience a failure with a turned up 5.9 in an FL70?

    And is it Horsepower or torque that gets you up the hill?
     
  17. 90plow

    90plow Senior Member
    Messages: 737

    Now your just being a ball buster. Im giving actual advice against tuning a truck you use for work. I had a tuned up 5.9 for play and i plowed with it and anytime i plowed with it i de tuned (high egts trans temps etc). Horsepower wars aregreat in pickups but when you step out side of that if you dont have a big displacement motor your still only going to get so much. Hp is no doubt the number you need to go up hill on the highway and maintain 65mph. Take that same hill and a stop light at the bottom you need torque so its two different situations. If your theory on hp being the sole need in a big truck why dont the use a 6.7 powerstroke in my mack?
     
  18. Mark Oomkes

    Mark Oomkes PlowSite Fanatic
    Messages: 10,868

    Pretty sure 2COR is not saying high HP is the theory he is after.

    AS for high EGT's and tranny temps, it all depends on the setup. My tranny temps have dropped significantly in my F350 with the Cummins compared to the 6.0. EGT's are higher, but not dangerously so and really only when I put a big load on it.

    As an aside, why is it when someone's statements are challenged they are called names, such as: ball buster; touchy, closed to other's opinions. Yet the person making that statement is touchy about having his statements questioned as well as closed to the possibility of someone else knowing more than him?
     
  19. SnowFakers

    SnowFakers Senior Member
    from CT
    Messages: 942

    I really dont think that its cranking up HP that destroys reliability in trucks, I attribute it to people who beat the daylights out of their truck since they are turned up. Go easy and anything will last. Cranking it up wont make the engine go any less miles, it just doesnt help for sure.
     
  20. bcramblit

    bcramblit Member
    Messages: 35

    First off... Tuning a med. duty truck for work is a totally different ballgame than tuning a pickup. The weight of these trucks will burn little 5.9's alive (when loaded) and not properly tuned. Most people with advice on this matter have never felt the burden of being loaded at 30,000lbs or better. If they have, most will tell you to leave it alone.
    The first thing you need is a pyrometer. After that, the best and cheapest mod you can do is make sure your engine is governed at 3200rpm. If its not, change the governor springs. Its a must.
    You need to find the CPL# of your Cummins. You have to know where your starting from. I'm guessing its a #1552 rated at 210HP. These were tuned for Med. duty trucks, motorhomes, buses, equipment. You can tune it to your liking. You will be limited to EGTs at that point. If you pull heavy it won't take much more than stock to max EGTs. If you don't pull heavy it will take a bigger tune. Either way you will be glued to the pyro. If you have employees you have to ''idiot proof'' so just the governor springs will do most good. As little gains as you will use for this, the reliability is not a factor.
    Also, it is a 94' so if it has a lot of miles or exposed to harsh conditions it may not be performing to its stock rating. The fuel shutoffs go bad and restrict flow cause they don't open fully. If that is the case none of these mods will do any good so might want to start by checking that all systems are up to par before moving forward.

    P.S. Its nice to have power, but its a burden at the same time.
    Good Luck...:mechanic: