Announcement

Collapse
No announcement yet.

Why do you lose a % and not a given hp#????

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    [quote]G-E wrote:
    Originally posted by enjoyrth
    I don't see why this thread continued past the first reply with the "coefficient" theory. To simplify this even more, lets say you have a box that you are pushing and there is friction coefficient of k. If you push it with x newtons, then you will lose kx of the force you applied due to friction. If you push it again with x+25 newtons, you will lose k(x+25) of the pushing force. There is a coefficient similar to this friction coefficient in your drivetrain. You could think of x as your drivetrain loss in the case at hand. I know this disregards Jason's post on different RPMs, but i was just trying to simplify this as much as possible.
    the conversion from energy into useful work is non-linearly efficient, just like drag doesn't linearly increase either
    no real life application is perfectly linear, but my simple example was meant to be just that, simple.

    440whp on pump fuel and the STOCK MAF

    Comment


    • #17
      enjoyrth wrote: no real life application is perfectly linear, but my simple example was meant to be just that, simple.
      and since you missed it I did mention reducing it to a percentage is adequate, but each car's number will be a little different, it wouldn't be unreasonable to assume >12% for a 2wd and >18% for 4wd and just leave it at that

      Comment


      • #18
        simple thouht a tranmmison send your horsepower through gears that change ratio's. i have no clue but im guessing at say 50 your wheels are turning at alot more than say 2500rpm so in the conversion to a higher rpm you lose power. if you had a transverse motor and the flywheel was geared direct to the axle with some sort of clutch involed i wonder the differance between flywheel horsepower and wheel horsepower. just a random logical with no proof thouth.

        -Pete

        Comment


        • #19
          What about rotational mass?

          I agree with the above discussion but mass has a play here. I couldn't even begin to qualify how much compared to friction but I would think it would be quite significant overall.

          One other thought that hasn't been mentioned. Absorption loss. IE- play/flex in connecting parts. ( rubber mounting items that connect to drive-train components) The absorption of power into mounting parts, shouldn't be overlooked.

          Just tossing it out there. :wink:
          Just stand back and throw money.
          Performance costs money.
          Reliable performance costs more.

          Comment


          • #20
            OR-Zman wrote: What about rotational mass?

            I agree with the above discussion but mass has a play here. I couldn't even begin to qualify how much compared to friction but I would think it would be quite significant overall.

            One other thought that hasn't been mentioned. Absorption loss. IE- play/flex in connecting parts. ( rubber mounting items that connect to drive-train components) The absorption of power into mounting parts, shouldn't be overlooked.

            Just tossing it out there. :wink:
            that would be relatively limited and would not change significantly with rpm or torque

            Comment


            • #21
              so therefore why do yo lose horepower through a trans and a diff? Exactly why stated because those gear are some what heavy and you need to spin them that horsepower so you have used you horesepower. therfore you have less to accelerate/spin your wheels/tires. seems a perfectly logical thought. the give/play in your motor mounts,trans mount, diff mout specifficly the rubber parts would i think cause you to lose power for a second maybe slightly more until they reach the end of there play. for example a full throttle 2 gear downshift would cause the driveline to shift in its mount. therefore robing horsepower durning that movement.

              Comment


              • #22
                rc10ps85 wrote: so therefore why do yo lose horepower through a trans and a diff? Exactly why stated because those gear are some what heavy and you need to spin them that horsepower so you have used you horesepower. therfore you have less to accelerate/spin your wheels/tires. seems a perfectly logical thought. the give/play in your motor mounts,trans mount, diff mout specifficly the rubber parts would i think cause you to lose power for a second maybe slightly more until they reach the end of there play. for example a full throttle 2 gear downshift would cause the driveline to shift in its mount. therefore robing horsepower durning that movement.
                if that was to me you misunderstood, I agree with all that, it was the loading of the chassis and bushings that's not important

                Comment


                • #23
                  its was both yours and OZ MAN's respones that made come up with that thought.

                  -Pete

                  Comment

                  Working...
                  X