I know that for every one productive response I get, I will get fifty from people telling me I am insane for trying to figure out how to accelerate my bike, as they will assume I will be doing this in the nude in a school zone while flailing a cat of nine tails, but I thought I would take one more stab at posting on these forums. So here goes:

The peak HP on my '07 600RR is 14000 RPM ( approximately, for the purpose of discussion) and the peak torque is 11000. Now on both this forum and the Kawasaki forum I have been advised to shift at peak HP or slightly after so that the clutch will catch at the peak HP. But at peak HP I have 10 ft. lbs. less torque than at the 11000 RPM torque peak. So I am having trouble wrapping my brain around that. Also, it just feels like I am getting my greatest instantaneous burst of power at 11000 RPM. Don't I want the clutch to catch at 11000 RPM? How can I be at max acceleration with 10 ft. lbs. less torque? I just don't get it. Can anyone explain it to me?

Hope someone can help. Thanks.

 

Check out the following article December 2004 - Gearing 101. It's mainly a discussion on gearing selection strategy for a race track. However, there is a section titled "Advanced Technique" that may answer your questions.

 

Look at it like this:

Torque is for starting off.
Horsepower keeps you going.

You wanna keep the engine at or near the peak HP range between shifts. Forget about your torquefigures once you're moving justworry aboutthe powerband.

 

You want to stay as close to peak horsepower as possible when shifting. This is purely an example but for the sake of discussion we'll go with 14,000rpm being maximum power output at 105hp. If you shift at 14,000rpm in 1st gear we'll say it brings engine rpm down to 11,500 in 2nd gear, but at 11,500 rpm the bike is only putting out 95hp. If one were to wait until 15,000rpm to shift into 2nd, the bike will be past it's horsepower peak, putting out less than 105hp, say 100hp. After shifting at 15,000rpm, it should land you at roughly 12,500 in second gear. Again for the sake of discussion we'll say the engine puts out 98hp at 12,500rpm, this is higher than the 95hp at 11,500.

To clarify.. holding out for the extra 1,000rpm before shifting will land the bike that much closer to the power peak when shifting into the next gear. The advantage to this is that the bike will be putting out more power going from 14,000 to 15,000rpm in first gear than it would from 11,500 to 12,500rpm in second gear.

Again, I stress that this is an example, I didn't take this from a dyno chart and I don't have the specific shift points figured out for your bike. I just put down reasonable numbers to help you understand.

 

horsepower and torque are both functions of one another, meaning that if you know HP at a given RPM, you can calculate the torque at that RPM, and the other way around. torque is what gets your bike moving, think of it like trying to break a bolt loose with a ratchet. you need torque (force times lever arm) to get the bolt moving. but once you've got the bolt moving, to keep it accelerating you need power (and horsepower is nothing more than a unit of measure for power). power is the ability to do work over time. although your torque peak is at (for example) 11,000 RPM, this doesn't necessarily mean that's the RPM that your engine can do the most work in a given amount of time (the definition of power).

so what this all means... once you get rolling, you want to stay at or near the RPM at which your engine produces peak HP, unless you're coming out of a slow corner or something like that where it might be beneficial to be closer to your peak torque's rpm (or somewhere between the two). it's impossible to say with certainty what the best shift point is for your bike, because it varies depending on so many factors. and since no two bikes are alike (no matter how tight the tolerances are on production and assembly), you'll just have to find that sweet spot through trial and error most likely.

 

Just curious, why won't you be naked in a school zone flailing a cat o nine tails??? Are you trying to take the fun out of riding?

LOL

 

just make sure you dont have any guns with you when you go through the school zone, they frown on that

 

There's quite a bit of mis-information posted here.
HP is just a product of torque and angular velocity (RPM).
HP =RPM xT(torque) x 5252(constant)
Torque is what moves the bike. HP is a result of torque. It's the torque, not the fact that you are already going a particular speed -that's important. Focus on the torque band. When you shift you should roughly center your shift on the peak torque so that as you leave a gear you are over the peak torque and when you enter the next gear you are under the peak torque RPM.Shifting to the exact peak torque RPM will just leave you accelerating into lower torque ranges. It's best to try and get more of the total area of the torque peak.
Hmmm... I'm not sure that was very clear. Here's the practicality of it. If you hit yourpeak torque at 11,000 RPM, always try andshift so the next higher gear drags the RPMs down to 10,000 RPM. That way you use more of the meat of the power band and keep your RPMs closer to that peak. People who talk about higher HP and ignore torque don't really understand the correlation of those units of measure. Trust me, I'm a mechanical engineer.

 

Ha, put this thread back in the closet. None of those people have posted here in a long, long time.

 

WOW


The dust got blown off this thread [:-]