Home Forums General Karting Discussion HP range of different motors

This topic contains 4 replies, has 5 voices, and was last updated by  Scott Newton 4 years, 3 months ago.

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  • #32974

    Matt
    Participant

    In effort to explain what it is that my son is doing racing ‘go karts’, can anyone provide a general range of what horsepower different motors make?  He is in a Rotax jr, having been running a Comer 80 last year and it is hard to describe to people that it is real racing, not just cruising around.

    Specifically a Rotax in both Jr and Sr formats.  I’d also be curious to confirm that a Comer 80 makes about 8hp.

    Often times when talking to people, most think of a go-kart as the 5hp type you find at the mini-golf range.  A few think of what you can rent at some indoor places, which albeit fun and give you a work out are not as fast as a Rotax jr.  I am just looking for reference points to provide as an explanation of the sport.

     

  • #32977

    brian downing
    Participant

    Most people ask me how fast he goes, not about the kart’s HP.

    Running the KT100 with Jr Sportsman restricted intake (races against C-80) I’ve seen my son hit 60MPH on a long straight. We probably could have geared for more speed but had to balance gearing for corner exit power with straightaway speed.

    Horsepower is relative, same dyno, same day different readings.
    I’m guessing that 8HP is a tad high, but close to a max in this class (C-80)
    Racestudio’s “engine analysis” says we’re making close to 6HP calculating from change in speed (Power = Work/Time)

    Rotax, next year :)

  • #32981

    Walt Gifford
    Participant

    I just tell them imagine going highway speeds in the walmart parking lot.

    Gif

    FAA certified jet engine and aircraft technician,
    Nicholson Speedway class champion 2001,
    Yamaha KT100 Service Center,
    41 years karting experience

  • #33025

    Mike Bray
    Participant

    I’ve been told a 125 shifter kart will do 0-60 in 3.5 seconds and tops out at about 120 MPH.

     

  • #33051

    Scott Newton
    Participant

    Some 125cc shifter data from my last autocross that had a “drag” start.  I suspect others can and have done much better…. I’m new to shifters, and haven’t really done much tuning yet.

    – 0-50mph (speed before we lifted for first corner) @ launch: 2.7s

    – 60ft times: 1.7s @ 43mph

    Based on that 0-60 in 3.5s seems very doable.  No idea what top speed is, since I’ve always run out of straightaway long before I was starting to feel any aero drag.

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