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2equis

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Posts posted by 2equis

  1. QUOTE(2equis @ Aug 9 2006, 04:59 AM)

    ..I'd remove the airbox and put K&N pod filters in before I'd hack it up with a saw.

    excellent idea.

    Dump the large airbox with ramair feed and swap for preheated air through pods.

    Heat is good

    Someone I know took a scrollsaw to the airbox lid of their VFR750, cut a 6" hole in the top and re-jetted. Said he gained about 8hp. I'd remove the airbox and put K&N pod filters in before I'd hack it up with a saw.

    And just where in that statement did I mention cutting up the airbox on a ramair Blackbird?? Oh wait... I didn't :icon_wall:

    Here's a link that may help you:

    http://www.readingcomprehensionconnection.com/

    20 posts in over 3 years... way to contribute!

  2. The change due to exhaust length has nothing to do with friction. It is all about the time it takes a positive pressure wave to travel the length of the pipe and exit the muffler causing a negative pressure wave to return up the pipe. When the timing of this causes the wave to arrive just before the exhaust valve closes the system is at max efficiency.

    If you shorten the pipe the neg wave will arrive earlier and the peak torque output will occur at higher rpm.

    I thought this stuff only applied to 2 strokes :icon_drool:

  3. QUOTE(testrider @ Jul 31 2006, 11:46 AM)

    QUOTE(Philip @ Jul 31 2006, 11:03 AM)

    "Phase-change material"

    ICE is a phase change material....goes from solid phase to liquid phase!

    I am not commenting on the effectiveness of the vest, it may do well, but that slogan is pure snake oil.

    Definition of PCM:

    http://www.pcmenergy.com/

    Phase Change Materials (PCMs) are "latent" energy storage materials. They use chemical bonds to store and release heat. The thermal energy transfer occurs when a material changes from a solid to a liquid, or from a liquid to a solid. This is called a change in state, or "phase." Ice changes phase when heated at 0 deg C and is converted to water.

    Yeah, what I said

    Like he said.... water.

    Ride in southern Arizona for a summer and then go back to SoCal. You'll be amazed how "cooling" a little perspective can be.

  4. +1 on the dremel tool.

    You DON't want to install it w/o a chain tool. Throwing a chain on the XX can cost you big money (if it doesn't kill you) Either spring $90 for the tool or take it to the shop.

  5. I am back to Roads myself and will probably not ever try anything else,

    Why??? Any performance issues? I get about 6000 miles out of a pilot road rear. I'm thinking that a pilot road rear and a pilot power front will wear equally and I'll get some "extra sticky" in the front.

  6. Definitely normal temp readings under those conditions.

    However... the stock suspension, even when new, is not going to do very well with a combined 530 lbs onboard.

    You probably should consider some suspension upgrades....

    And welcome to the forum, BTW.

    +1 ...and welcome

    XX Manual

    page 7

    There is alot of fudge factor built into these numbers but upgraded suspension and possibly running your tires at a higher PSI than norm are things to look into.

  7. What is a Horsepower?...

    The term "horsepower" was invented by James Watt to help market his improved steam engine. He had previously agreed to take royalties of one third of the savings in coal from the older Newcomen steam engines[5]. This royalty scheme did not work with customers who did not have existing steam engines but used horses instead. Watt determined that a horse could turn a mill wheel 144 times in an hour (or 2.4 times a minute). The wheel was 12 feet in radius, thus in a minute the horse travelled 2.4 × 2π × 12 feet. Watt judged that the horse could pull with a force of 180 pounds (just assuming that the measurements of mass were equivalent to measurements of force in pounds-force, which were not well-defined units at the time). So:

    This was rounded to an even 33,000 ft·lbf/min.

    Others recount that Watt determined that a pony could lift an average 220 pounds 100 feet (30 m) per minute over a four-hour working shift. Watt then judged a horse was 50% more powerful than a pony and thus arrived at the 33,000 ft·lbf/min figure.

    Engineering in History recounts that John Smeaton initially estimated that a horse could produce 22,916 foot-pounds per minute. John Desaguliers increased that to 27,500 foot-pounds per minute. "Watt found by experiment in 1782 that a 'brewery horse' was able to produce 32,400 foot-pounds per minute". James Watt and Matthew Boulton standardized that figure at 33,000 the next year.

    Put into perspective, a healthy human can produce about 1.2hp briefly and sustain about 0.1hp indefinitely, and trained athletes can manage up to about 0.3 horsepower for a period of several hours.

    Most observers familiar with horses and their capabilities estimate that Watt was either a bit optimistic or intended to underpromise and overdeliver; few horses can maintain that effort for long. Regardless, comparison to a horse proved to be an enduring marketing tool.

  8. I'm away from my normal resources but basically, every 90 degree turn in the drive train will incurr about a 5% penalty in drive efficiency due to friction losses in the gears. The BMW design involves two 90 degree turns as two sets of bevel gears are used, one at the output of the gearbox and the second at the final drive on the wheel. So, you incurr a 10% power loss to the rear wheel. It ain't all for free though as a chain drive is only about 97% efficient as well so the difference between the two drive methods works out to about 7%. Those are some pretty rough numbers and the smaller bevel gears up in the front might add a bit more friction.

    Bacl om tje early days of shaft drives, a lot of the Japanese mfgs used an intermediate gear box between the engine and drive shaft and used helical gears in there which are a good deal less efficient, although quieter, than the spiral bevel gears used by BMW. That may be where your 20% loss figure comes from.

    Is there a value for rear wheel friction or brake drag etc.?

  9. No way you are going to incurr a 20% penalty in the final drive.

    Everything I've read always gave a chain final drive a 10% loss between crankshaft and RW hp and shafties a 20% loss.

  10. does more H.P. always mean faster? All thing being relatively equal. Is the new beamer faster than the Bird.

    All "sportbikes" are about as aerodynamic as a barn door. That being said, "faster" comes down to HP and gearing. From what I've seen on this board and with my own XX the average RWHP on an XX is about 138. The shaft HP on the Beemer is about 162. The 20% shaft drive penalty brings the Beemer down to about 130 RWHP. My guess is the XX has a slight edge over the Beemer in top speed.

    FWIW

  11. I have to agree, loud pipes save lives. I know i know, it really annoys the hell out of people, but on my Ducati Monster, people could hear me coming a long way back and were always looking at me in their rearview. On my bird, even with staintunes (Australian), I feel much more vulnerable to cagers...

    According to the Hurt report is was determined that 77% of motorcycle accident hazards come from in front of the rider, while only 3% approach from the rear. What's interesting here is that motorcycle pipes direct the vast majority of sound backwards where the least danger is, so for loud pipes to be truly effective safety measures they would need to be pointed forward where the greatest danger lies.

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