inconsistant braking ??

Discussion in 'General' started by gixserman, Nov 29, 2003.

  1. gixserman

    gixserman Well-Known Member

    inconsistant engine braking ??

    I recently got a subscription to RRW and in reading some of the MotoGP reports I see that some of the teams have mentioned issues with engine braking or inconsistant engine braking...

    Can someone who knows a little more about this explain why this happens and maybe how they would tune this out..

    Last edited: Nov 29, 2003
  2. R Rahn

    R Rahn re-Member

    The 4 stroke gp machines are very "complex". Several of the motogp teams are using various types of ride-by-wire (electronic and computer controlled) components that change the way the engine behaves on the fly. Adjustable engine braking is one of the things they've been playing well as recieving as a side effect.

    Traction control is another toy they're working the kinks out of - see Hopkins multiple highsides at lemans for a good indication of what these guys are trying to overcome.
  3. WERA29

    WERA29 On a mental field trip...

    Yup, just like your home PC can crash at any time without a moment's notice, you can get flicked like a booger :wow: from a high-tech computer controlled bike. :D
  4. gixserman

    gixserman Well-Known Member


    On the electronic controls:
    Are we talking about cutting the rev's when the wheels spin
    like a rev limiter ??? Wouldn't that goof them up when they back it in sometimes?

    Another thing I guess I don't get is how do you change how an engine brakes ... will richening the mixture or altering the timing do this ?

  5. SmokeSignalRT

    SmokeSignalRT Fat Member

    I would guess with an ajustable slipper clutch.
  6. R Rahn

    R Rahn re-Member

    These guys are trying to milk the last possible 1/10's of a second per lap. They'll try anything and spend any amount of money to get there. Engine braking is just one of many ways to accomplish this. A lot of these guys came from 2 stroke backgrounds, where there was almost NO engine braking. I've read that (can't remember where) some riders wish they had NO engine braking again so they can have the braking feel they did with the two smokes.

    The ragged edge is a fine line, and in theory, the more adjustability you have on the bike the more likely it is to ride that b!@# for all its worth. On the other side of that sword: that's just that many more things to screw up and put you on your @$$.
  7. R Rahn

    R Rahn re-Member

    From my very limited understanding the GP gods are trying to push past that and get an even greater level of control over the bike under hard braking and frantic downshifting. 204.9 MPH is a LOT of speed to bleed off!!

    You've got me curious now. I'm gonna have to go pull out some old RRW and see what Mr. Oxley has to say on the subject.
  8. sqidd

    sqidd Well-Known Member

    If you read the whole artical, it explains what they are doing pretty good.

    Yamaha is rumord to be "hanging" the throttle blades open on a few cylinders to reduce engine braking. Obviously this is adjustable.

    Ducati is using the same slipper clutches (ramp style) as their super bikes. They are not very comlex and only cost about $1500 for the consumer version. These are adjustable by the spring tension.

    I can not remember what Honda was using, but I am sure it's the best.

    Suzuki and Aprilia are using electronic controlls.
  9. SmokeSignalRT

    SmokeSignalRT Fat Member

    One thing I found out that I thought was cool is that the new Kawasaki ZX6RR's slipper clutch is ajustable through shims that Kawasaki sells. Not bad for a bike that most of the public can afford.
  10. Yoyo

    Yoyo Well-Known Member

    Actually, the slipper clutches cost a lot less now,
    we have one for the gsxr 1k here
    slipper clutch

  11. sqidd

    sqidd Well-Known Member

    That is cheap! I just got a STM for my GSXR1000 ($1000), it's Grrrrrrrrrrrrrrrrreat. How does your work compared, some friends of mine have ridden my bike and are buying some.
  12. Johnny B

    Johnny B Cone Rights Activist

    On their Hybrid Civic sedan, Honda uses a variation of the V-Tec system to shut down three of the four cylinders in the engine. They say that it reduces internal engine friction (and braking).
    The freed up momentum in this particular application is used by the stator/rotor assembly to charge up the battery pack concealed inside the rear seat back.
    Last edited: Nov 29, 2003
  13. SmokeSignalRT

    SmokeSignalRT Fat Member

    I was at a local scrap yard here in Ga awhile back droping off some metal when I noticed 14 or 15 Hybrid Hondas on the lot. When I asked about them the guy working said they were prototypes that they were crushing for Honda. They had a rep form Honda there making sure that nobody got any parts or got too close to them before they got destroyed.
  14. gixserman

    gixserman Well-Known Member

    Thanks for the info guys

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