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Horsepower stats?

Discussion in 'Technical and Troubleshooting Torque' started by saeraph, Feb 15, 2005.

  1. I was just wondering where I could find out the horsepower stats for my 2004 zzr250, without getting out of my chair? I was asked this the other day and responded rather eloquently with a blank look :shock: *sigh* ... and really, what does that mean, exactly :? I mean this guy seemed to think horsepower was very important *shrug*

  2. hehehe.... arouns 1-1.5 i think :LOL:

    www.motorbikes.be has plenty of stats, but i doubt its all accurate :? seems to think that the ZZR/GPX has 38hp or so which i find pretty hard to beleive, the CBR is a fair whack quicker but apparently on 40hp.....

    makes your bike sound better tho i spose :wink:
  3. Google. You'll find all types of stuff.

    "ZZR250 Stats" or similar will do the job.
  4. sorry, it thinks the GPX has 36hp and the ZZR has 40hp (zachery the same motor :shock: ) and the CBR has 40 aswell :? ahwell, fun to look at eh :LOL:
  5. OK, thanks :)

    Deyago, I googled... THEN I asked, because I didn't find anything I could understand, and most of the hits came up here anyway :roll: sometimes I feel like a competent human... not today.

    Can anyone now tell me what it *means* to have 40hp rather than 35hp? If it was money, I'd understand - another pint :D - but what difference does 5hp at 12000 rpm make :?

  6. The GPX/ZZR 36 to 40 ps (not horsepower btw) figures that you see quoted are measured at the crank, not at the rear wheel.

    The 'real life' dyno figures would be somewhat lower :)
  7. and the Across 45ps, later Across's 40ps
  8. Just a comment... re the 5ps.

    The general consensus seems to be that somewhere around a 5% power difference can just be felt and that a 10% power difference is fairly obvious.

    with 35 and 40 ps 5 ps is more than 10% so it could be felt.

    But you are talking claimed figures and there is often more difference between bikes of the same model than 5% and sometimes more than 10%.

    You'd really need to dyno both bikes.
  9. HP figures are a bit of a nightmare, different dyno's, temperatures, air-flows (some dyno's blast nice cool air straight into the air-box for you) and even different altitiudes....it all effects the readings.

    Also the same bike will make different power depending on how it was run in and the luck of the draw with random assembly tolerances (whatever that means).
  10. So when the salesman told me that a new R6 has 120 hp I should have been more impressed? Hrmm...

    Also where does hp matter, off the mark or at the high end? not sure that question makes sense :?
  11. Torque is more important than HP and what is actually more relevant to us is the 'thrust curve' (which is gear ratio x torque).
  12. Mmm... wonder how much credit you can put into those HP/PS (more or less the same thing, btw, PS is metric HP, from what I understand). I know that my GPX250 accelerates and has almost exactly the same top speed as a mate's ZZR250, perhaps mine is even marginally quicker.

    But hey, it's a 250 - it's meant for corners :p
  13. your also looking at 10kg dri weight difference between the GPX and ZZR to, that makes alot of difference also rider weight etc etc
  14. Tenoq, you have just hit the nail on the head. If you look at a dyno chart plotting hp/revs it is the amount of area under the line that is important. The steeper the hp line from low revs to peak power shows higher torque. This is what accelerates the bike. If the line is flatish up to higher revs then heads up sharply to a high peak power the engine will have a real "hit" but you have to keep the engine in that narrow rev range -you will have to change down a few gears to pass something whereas the 1st example all you have to do is roll the throttle on. Your GPX will have more torque at lower revs & will keep up even though the ZZR has more peak power
  15. Basically (simplifying lots and lots), torque is acceleration and horse power is top speed.

    Yes I know... this ignores gearing ( so just say torque is in gear acceleration ok :)
  16. I found a site with a few dyno charts. Althought they are with an exhaust mod. If you look at jsut the 250s there isnt going to be much difference between stock and modded. It also has figures on larger bikes with sometimes a stock curve. I think i found my bike to have the least hp of the lot but i still love my vtr250. It doesnt display torque but it does stat that the cbr250rr has around 40hp at the wheel, and the across has about 30 hp. But there is no readings for the zzr250. best i could find.
  17. yeah that goes with what a few on the across forum found after a dyno 96 Across around the 30-32 at the back wheel
  18. I seem to remember reading somewhere that in Japan 4-stroke 250s are restricted to an output of no more than 40ps but there is no restriction on torque. Consequently for a 250 the amount of torque produced at what RPM (ie the torque curve) will probably be more important than peak horsepower.