worlds fastest dirt bike

[k5abuser]

ug uggg mor poweer. the need . the need for speed. on its way.

[Good]

the ZX has a measured coefficent of drag of ~0.603 while a busa slips in at ~0.561.

I was thinking the same thing...

[k5abuser]

remember boys and grils . It ani't fast unless its kx 500 powered. he was hualing azz when i went past him on one wheel. or did i slide pass him. oh well he was fast. lol

[Friar-Tuck]

 The ZX-14 also uses a ram-air type induction intake on front end.
 
   (from Kawasaki.com ZX-14)
"Ram Air Induction.
- Central Ram Air duct produces a straighter path to the airbox for maximum intake efficiency
- This system takes cooler, high-pressure air from in front of the fairing and guides it through the air cleaner and into the engine for maximum power output"

  Is there a way to figure out [using math] if the size of the opening in the fairing at 130mph would overcome the intake velocity being drawn into the carb ??
 
Tuck \o/

[mdw471]

Tuck

my opinion about Ram Air Induction.....at least so far!

in-line four cylinder motors take 4 little 187cc/250cc sips of air for every large 500cc gulp of say a tl1000 or a kx500.

The graph of a manometer placed in the tl1000 airbox shows vicious 'pulses' of low and high pressure in the airbox

compared to

the in-line fours gradually building airbox pressure as three digit speeds increased.

What say you Tuck.....any exeperience with pressurized airboxes?

Mark

[mdw471]

Here is a link to a guy named Scooter Grubb that was at the BUB event.

http://www.scootershoots.smugmug.com/gallery/6013406_4JM7d#377166360_P9m7L

In addition to the beautiful P/P KX500 shot that I have selected in the link, there are hundreds of other shots that give a tase of what the event is like.

Mark

[Friar-Tuck]

 Mdw,
I think you might find this article of some interest.   (it is a bit dated, but valid I think)

http://www.sportrider.com/tech/146_9508_ram/index.html

  I understand the Helmholtz effect of the intake tract/ports cylinder charging, exhaust and all, and the cost would be crazy to engineer a workable "Tuned" induction for max hp./rpm at whatever Stewart would build the engine for.
 
 As a very loose rule of thumb, just compare the dynamic pressure at the speed you're travelling against atmospheric ambient.

Dynamic pressure = 0.5 * density * speed^2
120mph ~ 54m/sec
density ~1.225 kg/m^3
      the dynamic pressure at 120mph is about 1800Pa.
   Atmospheric ambient will be somewhere around 101300Pa, so about 1.8% 'more air'.
So not a lot, but some.  Thats why the guys in the article saw the hp go up with speed.
 I'm not for sure, but what could Stewart do with 1.8% more air forced in the engine.
   Just a thought... 

Tuck \o/

[mdw471]

interesting link...thanks Tuck

[k5abuser]

mark time is ticking . looking forward to more power as i know everyone is . like me and stewart say after a ride , that was fast now what !!! . ill shave my head if that is what it takes to go fasterrrr

[mdw471]

mark time is ticking . looking forward to more power as i know everyone is . like me and stewart say after a ride , that was fast now what !!! . ill shave my head if that is what it takes to go fasterrrr

okay okay okay k5A I am workin on it !!! Did stewart send you to rough me up a bit !?! 

Mark

p.s. I thought you already shaved your head to make it easier to pick out the boogers that stewart's motor sticks in the back of you helmet! 

[gwcrim]

Congratulations on a job well done.  I know first hand how hard it is to compete and be successful on the salt.  It looks much easier on the internet sidelines.  For most, success is just getting there.  Having a trophy or two on the shelf is.... priceless!

I gotta ask, why wouldn't say a Yamaha RZ500 own all of the 500cc records?

[k5abuser]

the rz500 is a street bike and it is a stock class dirtbike or mod'd dirtbike.

[gwcrim]

There's a dirt bike class???  Is that relatively new? 

[Hillclimb#42]

I gotta ask, why wouldn't say a Yamaha RZ500 own all of the 500cc records?

Stewart doesn't work on those

[mdw471]

Here we go......

There's a dirt bike class???  Is that relatively new? 

The competition class is defined by the frame and then the engine size. We were running in the MPS / P class because that is where the Hando guys from F2 run. The goal was W'sFDB and it just so happens that the bikes fit in the AMA's MPS/P class.

Congratulations on a job well done.  I know first hand how hard it is to compete and be successful on the salt.  It looks much easier on the internet sidelines.  For most, success is just getting there.  Having a trophy or two on the shelf is.... priceless!

Thank you! This was absolutlely a team effort.....I couldn't be any prouder.... see 3500 and 1471! http://www.speedtrialsbybub.com/2008_event/results08.html

I gotta ask, why wouldn't say a Yamaha RZ500 own all of the 500cc records?

Stewart doesn't work on those

Ummmm true about Stewart! Considering the RZ......I bet it is twice the weight of the 3500 bike, the EPA and DOT snuffed alot of its ability, did I mention the thing is really really heavy! Also really complicated with splined crank shafts 

Thanks for the interest!

Mark