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#### Soul Searcher

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For some reason, known only by the owner of a CBR250R. The Century Mark (100 mph, (160 Kph)) seems to be a magic number.

To cover this distance, the Time involved is 1 Hour. Let’s break this 100 mph (160 Kph) down to a smaller unit.

The next smaller unit would be the Minute.

100 mph divided by 60 minutes equals 1.666666666666667 miles per minute.
160 Kph divided by 60 minutes equals 2.666666666666667 Kilometers per minute.

Let’s take this example down to a smaller unit. The next smaller unit of time is the Second.

1.666666666666667 miles per minute / 60 seconds = 0.0277777777777778 miles per second.
2.666666666666667 Kilometers per minute / 60 seconds = 0.04444444444444445 Kilometers per second.

Anybody have any Idea how much distance 0.0277777777777778 mile or 0.04444444444444445 Kilometer is ?

If you do, I bow to the Mathematicians.

We need a simpler way to convert and a unit that makes more sense. How about Feet and Meter per Second ?

1 mile = 5,280 ft. 5,280 ft / 60 min = 88 feet per minute. 88 fpm / 60 seconds = 1.466666666666667 feet per second.

Now we have a decimal part of a foot. We need to convert this to inches.

1 foot = 12 inches. 12 inches multiply by .466666666666667 = 5.6 inches.

For easy calculation, less round it up to 6 inches.

Now we have a distance of 1 foot 6 inches per second for each 1 MPH of Speed.

For calculating feet per second, we need to change this to a decimal equivalent. So 6 inches equals 1/2 of a foot. With a decimal equivalent equal to .5.

Now we have a constant of 1.5 Feet per Second for each 1 MPH in Speed.

Now about that Speed of 100 mph. 100 multiplied by 1.5 equals 150 feet per second. Or, half the length of a football field.

Now for the Metric Members and Guests.

1 Kilometer = 1,000 meters. 1,000 meters / 60 minutes = 16.66666666666667 meters per minute.
16.66666666666667 meters per minute / 60 seconds = 0.2777777777777778 meter per second.

For easier calculation, we’ll round 0.2777777777777778 meter to .3 meter.

Now we have a constant of .3 meter for each 1 Kilometer in Speed.

Now about that Speed of 160 Kph. 160 multiplied by .3 equals 48 meters per second. Almost half the length of a Rugby Field (100 meters in Length).

The Following Information courtesy of :

The Fastest Land Speed Record in The World | Scienceray

Land Speed Record, 763.035 mph, 1,227.985 kph, Mach 1.020.

Even at this fast of a Speed, it’s still hard to comprehend. Let’s change it to a unit, that will make it easier to understand.

763.035 x 1.5 = 1,144.5 feet per second. Almost 4 Football Fields a second.
1,227.985 x .3 = 368.4 meters-per second. Over 3.5 Rugby Fields a second.

What is a use for this Information. For one, calculating your distance, while following a vehicle. Pick a stationary object that the vehicle in front of you passes. Sign, mail box, tree, light pole or reflector in the highway.

Now start counting, 1,001, 1,002, etc.

If your speed was 30 mph and you counted to 1,002.

30 mph x 1.5 = 45 ft per sec. 45 x 2 = 90 feet to the vehicle in front of you.

If your speed was 50 Kph and you counted to 1,002.

50 Kph x .3 = 15 Meters per sec. 15 x 2 = 30 meters to the vehicle in front of you.
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Ouch.

#### 250 Tom

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879 Posts  Wow what a post? thats a ton of info.

#### j4bberwocky

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My bbbrain hurts (in a wrapped head, Monty Python voice)

#### Conundrum

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Too much info/math -- but at least now I know how the Stig must think on a day-to-day basis.

#### Soul Searcher

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So much to Learn.

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Basic Information. Just the tip of the iceburg.
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#### Rick

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For some reason, known only by the owner of a CBR250R. The Century Mark (100 mph, (160 Kph)) seems to be a magic number.

To cover this distance, the Time involved is 1 Hour. Let’s break this 100 mph (160 Kph) down to a smaller unit.

The next smaller unit would be the Minute.

100 mph divided by 60 minutes equals 1.666666666666667 miles per minute.
160 Kph divided by 60 minutes equals 2.666666666666667 Kilometers per minute.

Let’s take this example down to a smaller unit. The next smaller unit of time is the Second.

1.666666666666667 miles per minute / 60 seconds = 0.0277777777777778 miles per second.
2.666666666666667 Kilometers per minute / 60 seconds = 0.04444444444444445 Kilometers per second.

Anybody have any Idea how much distance 0.0277777777777778 mile or 0.04444444444444445 Kilometer is ?

If you do, I bow to the Mathematicians.

We need a simpler way to convert and a unit that makes more sense. How about Feet and Meter per Second ?

1 mile = 5,280 ft. 5,280 ft / 60 min = 88 feet per minute. 88 fpm / 60 seconds = 1.466666666666667 feet per second.

Now we have a decimal part of a foot. We need to convert this to inches.

1 foot = 12 inches. 12 inches multiply by .466666666666667 = 5.6 inches.

For easy calculation, less round it up to 6 inches.

Now we have a distance of 1 foot 6 inches per second for each 1 MPH of Speed.

For calculating feet per second, we need to change this to a decimal equivalent. So 6 inches equals 1/2 of a foot. With a decimal equivalent equal to .5.

Now we have a constant of 1.5 Feet per Second for each 1 MPH in Speed.

Now about that Speed of 100 mph. 100 multiplied by 1.5 equals 150 feet per second. Or, half the length of a football field.

Now for the Metric Members and Guests.

1 Kilometer = 1,000 meters. 1,000 meters / 60 minutes = 16.66666666666667 meters per minute.
16.66666666666667 meters per minute / 60 seconds = 0.2777777777777778 meter per second.

For easier calculation, we’ll round 0.2777777777777778 meter to .3 meter.

Now we have a constant of .3 meter for each 1 Kilometer in Speed.

Now about that Speed of 160 Kph. 160 multiplied by .3 equals 48 meters per second. Almost half the length of a Rugby Field (100 meters in Length).

The Following Information courtesy of :

The Fastest Land Speed Record in The World | Scienceray

Land Speed Record, 763.035 mph, 1,227.985 kph, Mach 1.020.

Even at this fast of a Speed, it’s still hard to comprehend. Let’s change it to a unit, that will make it easier to understand.

763.035 x 1.5 = 1,144.5 feet per second. Almost 4 Football Fields a second.
1,227.985 x .3 = 368.4 meters-per second. Over 3.5 Rugby Fields a second.

What is a use for this Information. For one, calculating your distance, while following a vehicle. Pick a stationary object that the vehicle in front of you passes. Sign, mail box, tree, light pole or reflector in the highway.

Now start counting, 1,001, 1,002, etc.

If your speed was 30 mph and you counted to 1,002.

30 mph x 1.5 = 45 ft per sec. 45 x 2 = 90 feet to the vehicle in front of you.

If your speed was 50 Kph and you counted to 1,002.

50 Kph x .3 = 15 Meters per sec. 15 x 2 = 30 meters to the vehicle in front of you.
.

Thanks. So have you been to 100MPH on a 250cc motorcycle?

#### motorpsycho

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Are you on speed? If so, care to share it with the rest of us?

#### Soul Searcher

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Normal Idle for the cbr is 1,400 rpms. The ECM doesn’t count RPMs by the minute. Maybe, keeps count by the Second.

So at Idle, it’s 1,400 / 60 seconds. Which equals 23.3 rpms per second. Or 1 revolution every 42.9 milliseconds.

So much for the ECM counting RPMs by the second. At this point, maybe it counting in milliseconds (1,000 times a Second).

Let’s increase the Throttle to 5,250 RPMs. 5,250 / 60 seconds = 87.5 rpms per second. Or 1 revolution every 11.4 milliseconds.

Full Throttle, 10,500 RPMs. 10,500 / 60 = 175 rpms per second. Or 1 revolution every 5.7 milliseconds.

How High does the RPMs have to reach, before you pass the ECM’s counting ability in milliseconds. Pass 60,000 RPMs.

I think the cbr’s ECM is up to this task.

What other parts of the Power Plant are operating at this rate ?

The cbr is only equipped with a crankshaft sensor. It sends a pulse to the ECM on each revolution of the crankshaft.

The Ignition System on the cbr is known as a Wasted Spark Type. Meaning the Spark Plug fires for each revolution of the engine. Compression and Exhaust Stroke.

What tells the ECM when the engine is on the Compression Stroke ?

No Sensor for this operation is installed on the cbr. This Function, if the engine is so equipped, is performed by a component, known as a Camshaft Sensor. Being that the Camshaft is rotating at 1/2 the speed of the Crankshaft. Remember that the timing is set at TDC on the Compression Stroke.

What about Pulsing the Injector. If the ECM doesn’t know when the Piston is on the Compression Stroke, how is this controlled ?

Simple, take the calculated injector pulse width time (in milliseconds). Divide by 2. Now pulse the injector with the new time on each revolution of the crankshaft.
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#### Soul Searcher

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If you feel the need for Speed.

Thanks. So have you been to 100MPH on a 250cc motorcycle?
Yes, many times. Back in the days, when it was called Road Racing.
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#### feliz

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Fastest 250 I've had was an 80s Honda VTR, I think 35 hp. Would easily do a hundred.

#### Soul Searcher

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Speed - Life in the Fast Lane.

Are you on speed? If so, care to share it with the rest of us?
No. Living life to your fullest, is all the Speed I need.

Something that some people have a hard time trying to figure out.
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#### Top

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No. Living life to your fullest, is all the Speed I need.

Something that some people have a hard time trying to figure out.
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so thats a no on the sharing then? i do love alittle math in the morning... gets the brain going

#### Jackison

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thank you so much for the useful information.

#### Soul Searcher

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Just a Store House of Information.

thank you so much for the useful information.
You're Most Welcome.

#### Soul Searcher

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When computing Math in milli and micro units, some small errors will be encountered.

Valve Specfication for the CBR250R Engine.

intake valves
open 20 deg BTDC
close 35 deg ABDC

exhaust valves
open 40 deg BBDC
close 0 deg TDC

How long are the valves opened during one crankshaft revolution.

First at 1,400 rpms. One rotation of the crankshaft takes 42.9 milliseconds.

Now we need to know the time for each Degree or rotation.

First we convert the milliseconds to a Second. 42.9 milliseconds = .0429 Second.

.0429 second / 360 degs = 1.191666666666667e-4 Second = .000119 Second = 119 microseconds.

So, 119 microseconds for each degree of rotation of the crankshaft.

The intake valves opens 20 degs before TDC + 180 degs to BDC + 35 degs after BDC for a total open duration of 235 degs.

First let's check the math, to see if we have the correct Time for each Degree of rotation.

360 degs x .000119 sec (119 microseconds) = .0429 Sec = 42.9 milliseconds.

For the intake valves opening of 235 degrees on the Intake Stroke is :

235 degs x .000119 sec (119 microseconds) = .028 sec = 28 milliseconds.

To check if this answer is correct, let's compute the time for the Remaning 125 degs that the Valves are Closed.

125 degs x .000119 sec (119 microseconds) = .01489 Sec = 14.89 milliseconds.

235 degs - 28 00 milliseconds
125 degs - 14.89 milliseconds
----------------------------
360 degs - 42.89 milliseconds

Now that wasn't so terrible, was it ?

Now for the Exhaust Valves.

On the Exhaust Stroke, the exhaust valves starts to open at 40 degs BBDC and closes at 0 degs TDC.

For an open duration of 220 degrees.

220 degs x .000119 sec (119 microseconds) = .02618 sec = 26.18 milliseconds.

To check the Answer. Check the Time that the exhaust valves are closed.

140 degs x .000119 sec (119 microseconds) = .01666 sec = 16.66 milliseconds.

220 degs - 26.18 milliseconds
140 degs - 16.66 milliseconds
----------------------------
360 degs - 42.84 milliseconds

Now to Half Redline.

5,250 RPMs. 5,250 / 60 seconds = 87.5 rpms per second. Or 1 revolution every 11.4 milliseconds.

Convert 11.4 milliseconds to a Second. Which is .0114 Second.

.0114 / 360 = 3.166666666666667e-5 Second = .0000316 Second = 31.6 microseconds.

Intake Valves Opened. 235 degs x .0000316 sec = .00744 Sec = 7.44 milliseconds.

Intake Valves Closed. 125 degs x .0000316 sec = .00395 Sec = 3.95 milliseconds.

235 degs - 7.44 milliseconds
125 degs - 3.95 milliseconds
---------------------------
360 degs - 11.39 milliseconds.

Exhaust Valves Opended 220 degs x .0000316 sec = .006966 Sec or 6.966 = milliseconds.

Exhaust Valves Closed 140 degs x .0000316 sec = .004433 Sec or 4.433 milliseconds.

220 degs - 6.966 milliseconds
140 degs - 4.433 milliseconds
----------------------------
360 degs - 11.399 milliseconds.

Now to Full Redline.

10,500 RPMs. 10,500 / 60 = 175 rpms per second. Or 1 revolution every 5.7 milliseconds.

Convert 5.7 milliseconds to Second. Which is .0057 Second.

.0057 / 360 = 1.583333333333333e-5 Second = .0000158 Second = 15.8 microseconds.

Intake Valves Opened. 235 degs x .0000158 sec = .003720 Sec or 3.720 milliseconds.

Intake Valves Closed. 125 degs x .0000158 sec = .001979 Sec or 1.979 milliseconds.

235 degs - 3.720 milliseconds
125 degs - 1.979 milliseconds
----------------------------
360 degs - 5.699 milliseconds.

Exhaust Valves Opened. 220 degs x .0000158 Sec = .003483 Sec or 3.483 milliseconds.

Exhaust Valves Closed. 140 degs x .0000158 Sec = .002216 Sec or 2.216 milliseconds.

220 degs - 3.483 milliseconds
140 degs - 2.216 milliseconds
----------------------------
360 degs - 5.699 milliseconds.

The ECM isn't the only component that works in milli and micro Seconds.
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#### Soul Searcher

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Warp Speed !

How Fast is Warp Speed ?. . . . . . . . . . . . . . . A little Video before we start.

. . . . . . . . . . ..Would your Body survive the jump to Warp Speed in Earth’s Atmosphere ?

In the Original Star Trek Series. Warp Speed equaled Light Speed which is 186,282 miles per second also 299,792,458 meters per second. Now, we are talking Speed.

So what does this piece of Information have to do with the cbr ?

Electricity (AC or DC) in a complete Electric Circuit Travels (Flows) at the Speed of Light.

When an electrical component on the cbr has an electrical default. What kind of Test Equipment will be needed to Troubleshoot the affected component ?

Just Some Information to Think About. The Next time you take your cbr to a Shop for an Electrical Related Complaint.
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#### akira13

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Is there a point to this?

#### Slayer

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Or, you could just multiply 5,280 by .0277777777777778 to get 147 feet.

#### Soul Searcher

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