These numbers seem...high...
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Tourer
Joined: Oct 2008
Posts: 430
Likes: 1
From: Hampton, VA
These numbers seem...high...
I was using an HP calculator to get an idea of why my bike is putting out. I'm wondering what data I input wrong. I was expecting low to mid 80's but 95.21!?
Here's the results:
RSR Evo V-Twin Engine Calculations
Your V-Twin has a displacement of 81.78 cubic inches. Your deck height is NaN inches, i.e. center of crankshaft to top of cylinder. Your connecting rod length to stroke ratio is 1.75 to 1. You are running a static compression ratio of 9.5...With a stroke of 4.25 and a peak RPM of 6400 your piston speed is 4533.33 feet per minute. At peak rpm there are 8500.00 G's acting on the piston assembly, which weighs 23.58 Pounds as a result. Your motor is pumping 152.34 cubic feet per minute of air, resulting in 95.21 horsepower. Your inlet mach index number is 0.59 . You are running 0 PSI of boost with an ambient temperature of 68 degrees F. Your RSR Intercooler has an efficiency of 72 %. At this boost level the temperature of the compressed air reaches 68.00 degrees farenheit at the turbo nozzle, and 68.00 degrees farenheit exiting the intercooler. Turbocharged horsepower at a compression ratio of 8.5:1 would be 85.19 and would require 136.30 cfm of air at this boost level. To produce 122.67 horsepower, a larger turbo would be required to produce 196.27 cubic feet of air per minute.
Here's the link to the calculator http://www.rbracing-rsr.com/113orca.htm The calculator is at the bottom of the page.
Here's the results:
RSR Evo V-Twin Engine Calculations
Your V-Twin has a displacement of 81.78 cubic inches. Your deck height is NaN inches, i.e. center of crankshaft to top of cylinder. Your connecting rod length to stroke ratio is 1.75 to 1. You are running a static compression ratio of 9.5...With a stroke of 4.25 and a peak RPM of 6400 your piston speed is 4533.33 feet per minute. At peak rpm there are 8500.00 G's acting on the piston assembly, which weighs 23.58 Pounds as a result. Your motor is pumping 152.34 cubic feet per minute of air, resulting in 95.21 horsepower. Your inlet mach index number is 0.59 . You are running 0 PSI of boost with an ambient temperature of 68 degrees F. Your RSR Intercooler has an efficiency of 72 %. At this boost level the temperature of the compressed air reaches 68.00 degrees farenheit at the turbo nozzle, and 68.00 degrees farenheit exiting the intercooler. Turbocharged horsepower at a compression ratio of 8.5:1 would be 85.19 and would require 136.30 cfm of air at this boost level. To produce 122.67 horsepower, a larger turbo would be required to produce 196.27 cubic feet of air per minute.
Here's the link to the calculator http://www.rbracing-rsr.com/113orca.htm The calculator is at the bottom of the page.
Road Captain
Joined: Jan 2009
Posts: 518
Likes: 0
that could be what your engine should make, or makes at the flywheel.
Just like a 96" dyna makes 92ft lbs of tq from the factory, but you usually never see 80 at the wheel on a stock bike thats what i would think
Just like a 96" dyna makes 92ft lbs of tq from the factory, but you usually never see 80 at the wheel on a stock bike thats what i would think
Road Warrior
Joined: Jul 2007
Posts: 1,707
Likes: 4
From: Newtown, PA
Horsepower and torque at the crank and horsepower and torque at the rear wheel are not the same thing. And in any case, put your bike on a dyno if you want to know what horsepower and torque it makes. Theoretical is just that.
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Tourer
Joined: Oct 2008
Posts: 430
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From: Hampton, VA
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Outstanding HDF Member
Joined: May 2008
Posts: 2,166
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From: la
My T-Max will let mine rev high but the power drops off way before that, without cams designed to go there and headwork to go with it you're not getting no more power reving that high. Do a dyno run and see where it drops off. Do a search on dyno runs and look where "most" of the other bikes quit putting out.
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Road Warrior
Joined: Nov 2008
Posts: 1,789
Likes: 9
From: Double Oak, Texas
Click the link and visit the Harley Davidson "Screaming Eagle Pro Racing Parts" catalog. Fascinating read with Harley published corrected rear wheel HP and Torque for various stock Harley engines and various states of tune. It is a 17+ Megabyte PDF download.
http://www.harley-davidson.com:80/wc...key=2107621945
http://www.harley-davidson.com:80/wc...key=2107621945
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