Yessir, ah agree with you. Especially on the bikes w/o tachs - it's a guessin' game for 'em as to rpm, an' luggin' the engine definitely creates a LOTTA noise!

One thang, though - we ain't the onliest state in the union....but we ARE the smartest!!

 

I always thought that it's not just hp or torque alone, but rather a combination of the two that represents the "powerband" of a given engine. Peak acceleration will occur at peak torque, whereas peak hp simply represents the maximum amount of work the engine can produce. Torque accelerates the bike and hp (once you're in the proper gear) will dictate your top speed.

What we "feel" as power is really the torque the engine is making.

 

That dyno run shows a good picture of the power band, other then 1st or 2nd gear, I stay above 2500 rpms, runs perfect in that range.

 

OK, I think I see what you mean. Instead of saying "power," maybe we should be talking about "torque?" These HD engines make a great deal of good, useable torque just about anywhere in the RPM range. It's probably not good for the engine, but if you hammer down at 1100 RPM, the engine will pull like mad in any gear.

Since the engine will make torque way down low, the only question is "what is safe?" I mean there are low-oil-pressure issues, pre-detonation, piston-slap and all those things associated with lugging an engine.

 

Yes, I would agree with that. Seems to me, anything above 2500 RPM is perfect to stay in the powerband and not have any lugging issues. Power is definately not below that number.

 

Murphy, I'm definitely not talking about either horsepower or torque. I'm talking power as in a measurement of the amount of work done per unit of time. Power includes both HP and Q combined to produce the result of the rear wheel turning.

 

I have a 07 ultra with a 96ci stage 1. It starts to pull hard from 2,500-2,800 rpms starts to fade some around 4,000 but this is the seat of the pants dyno. I agree with staying around 2,500 rpms. I do not use 6th unless I am turning 2,800 rpms. Way to many hils around here. My mpg drops if I do not stay above 2,800 rpms in 6th.

 

Hmm, I guess I don't understand. What is Q? When you say "power as in a measurement of the amount of work done per unit of time," that is exactly what the definition of horsepower is.

 

Q is the matematical abbreviation for Torque.

Also, horsepower is really a measurement of potential to do work, Power is the result of that potential.

 

My 08 Ultra only has about 800 miles on it, but it seems to me to pull real good up to redline. I don't take it there very often, but it definitely does not hurt the engine to hit that line once in awhile. My normal riding style has me running much closer to 3000 rpm than 2000 execept for around town. I like the feel of the 2800 area, I know that if I twist the throttle I've got immediate power to get me out of trouble and have engine braking available by just letting off the throttle. I've only had my bike in 6th a couple of times, but that is usually when cruising 75-80 on the slab. I think this 96 ci engine runs better than the 88 in my Dyna when the rpms are kept up, the Dyna was much more forgiving if you missed a shift and found yourself in a higher gear than you expected.