Can I get more power out of 11.1L early DDECIII?

Discussion in 'Trucks [ Eighteen Wheelers ]' started by dhtrucking, Jun 5, 2011.

  1. Dirty-Low-Walker

    Dirty-Low-Walker Medium Load Member

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    I had one in a 94 Peterbilt tri axle dump set at 365 HP, great power for that size motor and excellent fuel mileage, that truck ran the same job along side 2 of my tandem macks and used 12-15 gallons less fuel per day then the Macks while hauling 5 ton more.
     
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  2. Ristow

    Ristow Road Train Member

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    Mine has the 357hp /1350lb program. It stays with my dads 425 3406c in the hills.
     
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  3. tnpete

    tnpete Medium Load Member

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    Anyone have any ideal, what RPM is best. For Optimum Fuel Mileage? I'm going to swap out the 295/22.5's on it. When I put new tires soon.
    10 Speed Direct trans, 2.93 rearend and came with 275/80-22.5's.
    Will be hauling low weight loads with it. So not looking for it to pull the best. Just burn less fuel while getting the job done. Should not get over 45,000 gross.
     
  4. stranger

    stranger Road Train Member

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    My 11.1 engines and 12.7 did best at 1650.
     
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  5. Oakcityarms

    Oakcityarms Bobtail Member

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    Once again an older thread but my 94 11.1 is a DDEC2 and has no rev limiter. I dont push it past 2100 and try to stay below 2000 rpm. The old man i bought it from swears it has been turned up but i have a 9 speed direct drive trans and at 1800 to 2000 rpm it has no staying power.

    Im curious if a bigger turbo and higher boost will work also aftermarket exhaust manifold and free up the intake will help?

    Do they make bigger injectors for it or can i swap in some from a 12.7 or 14L?

    I think i should have better HP at higher ranges. But with my trans and 3.36 gears, it does 2000 rpm at 70
     
  6. Hardlyevr

    Hardlyevr Road Train Member

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    Because these are electronically controlled engines changing injectors or turbos would require significant reprogramming, or just cause you problems.

     
  7. Kobethefarmer

    Kobethefarmer Bobtail Member

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    What Transmission were you running? In that 11.1.
     
  8. benjamin260_6

    benjamin260_6 Medium Load Member

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    This is not true. The ecm only controls when and how long the injectors fire. Changing to larger or smaller injectors changes the flow which will effect horsepower without any changes to the ecm. You can literally put 14L marine injectors into an 11.1L without changing anything in the ecm (other than cal codes...always change your cal codes) and it will run just fine
     
  9. Hardlyevr

    Hardlyevr Road Train Member

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    Which what I meant. Older mechanical engines when you changed turbos or injectors had nothing that needed reprogrammed.

     
  10. stranger

    stranger Road Train Member

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    I had a 1350 ft lbs Spicer 10 speed OD