If you upgraded to a 103 and now getting a dyno tune, do you have any choices like tune for max hp or minimum vibration or do they just go for max torque and hp and that's it!:xzqxz:
Dyno testing
- Thread starter Huelshorst
- Start date
When done correctly all of those areas should be covered.pepper
:Agree: They should tune everything from starting, through idle, and light cruise on up.
The tune should be for best efficiency and keeping your engine cool as possible. max horsepower is not something that a trike rider should be looking at. To get the max horsepower you have to rev your engine up above 5200 rpms to see the benefit from horsepower. Bring up your torque the horsepower follow
Getting the most torque in the rpms you ride in is what you want. Read this from well know engine builders >>
Torque breaks your wheels loose when you launch, and torque allows trucks to tow heavy loads. Torque accelerates your vehicle. Combine some measure of torque with speed and time, and the result is horsepower. Horsepower is what gets you through the quarter-mile. As far as which one is best, the answer is - it's best to have both. High torque numbers allow you to leave the gate quickly and power out of turns. High horsepower numbers keep the vehicle accelerating and give it a higher top end. Just as important as the peak numbers, though, is what your curves look like, and where those peaks are.
The TQ curve which will accelerate the bike the fastest is the one with the greatest area under the curve for the rev range of the engine. An engine might have a high horsepower peak at a high rpm, and a graph that looks like one side of a steep mountain. This means that in order to take advantage of the high horsepower, the rider must keep the engine at that high rpm. This requires more shifting, which can result in lost time. Flat curves mean that the rider can take advantage of the engine's power without as much shifting, but in order to obtain a flatter curve, an engine tuner must sacrifice some power. You can’t get performance at both ends of the power spectrum.
Low end power, low end torque—that’s what your Harley engine was designed to produce. Why? Because that’s the kind of power that counts in real-world riding—pulling away from stop lights, hauling a passenger, passing a car at 60 MPH in top gear.Take away that torque and you destroy your Hog’s “fun to ride” factor.
From in "Harley-Davidson Bolt-On Performance" - Denis Manning, owner of Bub Enterpirses.
In road racing, you can beat guys every time if you can beat them in the low RPM range coming out of a corner. The riding experience isn't top end, it's what it's like coming out of corners, what it's like accelerating from a standstill. That means all the RPM has to be good. You can give away 10 percent on the top and put it on the bottom and just kill other bikes with it - Torque is everything.
From in "Harley-Davidson Bolt-On Performance" - Jim Leonard, one of Vance & Hines top R&D Techs.
When you talk about exhaust systems with Harley guys, all you hear about is peak horsepower numbers. I think it's much more important to look at the torque curve on a Harley. You're talking about an engine that you're usually shifting on the street at 2500 to 3000 rpm. The area of the torque curve from 1500 rpm to 3000 is very important. That's where you're riding most of the time. Part-throttle is where most riders do most of their riding, and where a Harley is the most fun to ride. You didn't buy your $20,000 Harley to run it wide open up and down the street.
From in "Harley-Davidson Bolt-On Performance" – Bruce Tessmer of S&S.
Horsepower will tell you how fast you can go on the top end. Torque is how fast it will accelerate.
From HD Bolt on Performance book by Jerry Smith:
Aftermarket cams typically give you a powerband about 3500 rpm wide at best. You can get that boost in the low RPM range, or the midrange, or way up ther near the red part of the tach, but not all three. So it's important to think about how you ride, and where a camshft's power boost will do you the most good.
The type of bike you ride will tell you a lot about how your ride. If you're a touring rider on a bagger, and you often carry a passenger and luggage, you'll spend most of your time at relatively low RPM, say no higher than 4000. Since that's where most of your riding is done, that's where you'll want the most improvement. You might be tempted to get a cam that puts our more power at a higher RPM so you can pass trucks on the highway without downshifitng, but such a cam will gut your low-rpm power in favor of a top-end rush that you'll only use once or twice per ride.
Now let's say you ride a wide-tire Softail stripped down to the bare essentials, and you like nothing better than revving the engine at stoplights and dropping the clutch when the light turns green. You only ride the bike weekends and never carry a pasenger or luggage. You don't mind lackluster low-end performance - it's that top-end rush that you live for. In that case, a cam that packs most of its wallop above 3500 rpm will suit you just fine.
Torque article by the late Jim Feuling.
HARD AS IT MAY BE for those of us brought up to think of horsepower as the ultimate measure of an engine’s worth, we need to rethink our emphasis. Maybe we should add the word “Power” to torque because that is really what we’re after. The torque gives us the “feels good” sensation in the seat-of -the-pants evaluation of acceleration. Going back to the most basic understanding of an internal-combustion engine, we all know that it is the reaction of an ignited air/fuel mixture that drives the pistons down the bore, causing the crankshaft to turn. Obviously, the more energy released in that reaction, and the more energy used (rather than lost), the greater the force on the piston and the more twist there is on the crank. Torque is a measure of the ‘twisting force” of the engine. One of the ways engineers evaluate the power of an engine is by looking at the Brake Mean Effective Pressure (BMEP). The higher the BMEP, the higher the torque. Torque is a function of cylinder pressure and displacement, which is the scientific origin of the old speed merchant’s axion, “You can’t beat cubic inches.” The reason engineers look at the BMEP is that, unfortunately, with current rod design the peak pressure is reached when the piston is just past TDC (10 to 15 degrees) and decrease as the piston goes down. That peak pressure near TDC arrives at a time when the pistons/rods have the least amount of mechanical advantage for twisting the crank. As the piston moves downward, the volume increase, creating a cooling/refrigeration effect when we really want heat! In terms of the engines in street and racing trim, where an engine gets is all-important. An engine with a low BMEP has to run higher rpm to make the same power as an identical displacement engine the features higher BMEP. Shifting the maximum torque to a lower rpm range really makes the engine feel bigger.
A good low-end torque motor always has the advantage from stoplight to stoplight. Within the usable rpm range of most street engines, good torque is much more valuable than peak horsepower. Horsepower is rpm-related. In a racing situation, where the desired speed and rpm are know, high horsepower is good, so racing engines are tuned to make their power at high rpm. Outside of Bonneville, 95% of the driving public may only see peak power in their engines momentarily. Within each gear, we get up to maximum horsepower briefly and then have to shift before power drops. During acceleration through the gears, we are only getting perhaps 60% to 70% of the potential power to the ground because the engine must go through a range in each gear, and maximum power is available only for an instant. The rest is a compromise. The “perfect engine” would run at a single, specific rpm. Then everything, from cam timing to carburetion, exhaust design, intake manifolds, compression ratio, and combustion chamber shape could be designed to make optimum power at that speed. Engines that must operate within an rpm range are designed with compromises. What works best at 5000 rpm is not going to work as well at 4000 or 6000 rpm. Perfect engines can be easily built today. They are already in place as stationary engines all over the world, providing pumping power, and running electrical generators. For use in a car, truck, or motorcycle, we also need “the perfect transmission.”
From July 2003 Hot Bikes magazine: “Wayne “Speed” Hanson” Dyno Tuner w/over 40 years of tuning and racing experience.
Since Harleys are big bikes, it’s far more important to tune them for maximum acceleration than it is for top-end power. With a heavy bike like a Harley, you really want to concentrate more on bottom-and mid range performance, since those are the areas of the powerband that are the most important. Faster acceleration and a smoother power curve is always better than chasing a few extra ponies at the top.
Nigel Patrick (Patrick Racing) in American V-Twin Engine Hop-Up and Repair book "
Says he tries to build engines that have really good response between 1500 and 3500 rpm because that's where most of us ride most of the time."
RB Racing
Fuel Injectors
Is an engine that produces 135 hp is better than an engine that produces 125 hp?..Well maybe it is and maybe it isn't. What is the definition of horsepower anyway? The common definition is HP = (Torque x RPM) / 5252. Everyone is so enamored of peak horsepower these days that they will trailer their hot rodded V-Twin from dyno contest to dyno contest searching for bragging rights as to who has the most peak horsepower.
We hate to burst their ego-filled bubble, but in the real world it's the rate of acceleration that wins races, not peak horsepower. Torque is the most important element of the equation and if you can't produce torque in the lower rpm ranges it will take forever to get to the upper rpm ranges where the dyno junkies worship the God of peak horsepower. Every time you grab the next gear your rpms fall and you have to climb that elusive mountain to get back to those so damn important peak power readings. The rate of acceleration from one point to the next is how we judge a vehicle's performance, not how much peak horsepower it makes. The right question isn't peak horsepower but is the search for maximum torque in the rpm band that produces the greatest transient acceleration.
The next time you need a definition of useable power take a look at all the diesels roaming the highways. They are out there for a good reason, they make a bunch of torque right now, not at the top of the rpm band. A typical diesel will crank out 90% of its torque by 2000 rpm!
Getting the most torque in the rpms you ride in is what you want. Read this from well know engine builders >>
Torque breaks your wheels loose when you launch, and torque allows trucks to tow heavy loads. Torque accelerates your vehicle. Combine some measure of torque with speed and time, and the result is horsepower. Horsepower is what gets you through the quarter-mile. As far as which one is best, the answer is - it's best to have both. High torque numbers allow you to leave the gate quickly and power out of turns. High horsepower numbers keep the vehicle accelerating and give it a higher top end. Just as important as the peak numbers, though, is what your curves look like, and where those peaks are.
The TQ curve which will accelerate the bike the fastest is the one with the greatest area under the curve for the rev range of the engine. An engine might have a high horsepower peak at a high rpm, and a graph that looks like one side of a steep mountain. This means that in order to take advantage of the high horsepower, the rider must keep the engine at that high rpm. This requires more shifting, which can result in lost time. Flat curves mean that the rider can take advantage of the engine's power without as much shifting, but in order to obtain a flatter curve, an engine tuner must sacrifice some power. You can’t get performance at both ends of the power spectrum.
Low end power, low end torque—that’s what your Harley engine was designed to produce. Why? Because that’s the kind of power that counts in real-world riding—pulling away from stop lights, hauling a passenger, passing a car at 60 MPH in top gear.Take away that torque and you destroy your Hog’s “fun to ride” factor.
From in "Harley-Davidson Bolt-On Performance" - Denis Manning, owner of Bub Enterpirses.
In road racing, you can beat guys every time if you can beat them in the low RPM range coming out of a corner. The riding experience isn't top end, it's what it's like coming out of corners, what it's like accelerating from a standstill. That means all the RPM has to be good. You can give away 10 percent on the top and put it on the bottom and just kill other bikes with it - Torque is everything.
From in "Harley-Davidson Bolt-On Performance" - Jim Leonard, one of Vance & Hines top R&D Techs.
When you talk about exhaust systems with Harley guys, all you hear about is peak horsepower numbers. I think it's much more important to look at the torque curve on a Harley. You're talking about an engine that you're usually shifting on the street at 2500 to 3000 rpm. The area of the torque curve from 1500 rpm to 3000 is very important. That's where you're riding most of the time. Part-throttle is where most riders do most of their riding, and where a Harley is the most fun to ride. You didn't buy your $20,000 Harley to run it wide open up and down the street.
From in "Harley-Davidson Bolt-On Performance" – Bruce Tessmer of S&S.
Horsepower will tell you how fast you can go on the top end. Torque is how fast it will accelerate.
From HD Bolt on Performance book by Jerry Smith:
Aftermarket cams typically give you a powerband about 3500 rpm wide at best. You can get that boost in the low RPM range, or the midrange, or way up ther near the red part of the tach, but not all three. So it's important to think about how you ride, and where a camshft's power boost will do you the most good.
The type of bike you ride will tell you a lot about how your ride. If you're a touring rider on a bagger, and you often carry a passenger and luggage, you'll spend most of your time at relatively low RPM, say no higher than 4000. Since that's where most of your riding is done, that's where you'll want the most improvement. You might be tempted to get a cam that puts our more power at a higher RPM so you can pass trucks on the highway without downshifitng, but such a cam will gut your low-rpm power in favor of a top-end rush that you'll only use once or twice per ride.
Now let's say you ride a wide-tire Softail stripped down to the bare essentials, and you like nothing better than revving the engine at stoplights and dropping the clutch when the light turns green. You only ride the bike weekends and never carry a pasenger or luggage. You don't mind lackluster low-end performance - it's that top-end rush that you live for. In that case, a cam that packs most of its wallop above 3500 rpm will suit you just fine.
Torque article by the late Jim Feuling.
HARD AS IT MAY BE for those of us brought up to think of horsepower as the ultimate measure of an engine’s worth, we need to rethink our emphasis. Maybe we should add the word “Power” to torque because that is really what we’re after. The torque gives us the “feels good” sensation in the seat-of -the-pants evaluation of acceleration. Going back to the most basic understanding of an internal-combustion engine, we all know that it is the reaction of an ignited air/fuel mixture that drives the pistons down the bore, causing the crankshaft to turn. Obviously, the more energy released in that reaction, and the more energy used (rather than lost), the greater the force on the piston and the more twist there is on the crank. Torque is a measure of the ‘twisting force” of the engine. One of the ways engineers evaluate the power of an engine is by looking at the Brake Mean Effective Pressure (BMEP). The higher the BMEP, the higher the torque. Torque is a function of cylinder pressure and displacement, which is the scientific origin of the old speed merchant’s axion, “You can’t beat cubic inches.” The reason engineers look at the BMEP is that, unfortunately, with current rod design the peak pressure is reached when the piston is just past TDC (10 to 15 degrees) and decrease as the piston goes down. That peak pressure near TDC arrives at a time when the pistons/rods have the least amount of mechanical advantage for twisting the crank. As the piston moves downward, the volume increase, creating a cooling/refrigeration effect when we really want heat! In terms of the engines in street and racing trim, where an engine gets is all-important. An engine with a low BMEP has to run higher rpm to make the same power as an identical displacement engine the features higher BMEP. Shifting the maximum torque to a lower rpm range really makes the engine feel bigger.
A good low-end torque motor always has the advantage from stoplight to stoplight. Within the usable rpm range of most street engines, good torque is much more valuable than peak horsepower. Horsepower is rpm-related. In a racing situation, where the desired speed and rpm are know, high horsepower is good, so racing engines are tuned to make their power at high rpm. Outside of Bonneville, 95% of the driving public may only see peak power in their engines momentarily. Within each gear, we get up to maximum horsepower briefly and then have to shift before power drops. During acceleration through the gears, we are only getting perhaps 60% to 70% of the potential power to the ground because the engine must go through a range in each gear, and maximum power is available only for an instant. The rest is a compromise. The “perfect engine” would run at a single, specific rpm. Then everything, from cam timing to carburetion, exhaust design, intake manifolds, compression ratio, and combustion chamber shape could be designed to make optimum power at that speed. Engines that must operate within an rpm range are designed with compromises. What works best at 5000 rpm is not going to work as well at 4000 or 6000 rpm. Perfect engines can be easily built today. They are already in place as stationary engines all over the world, providing pumping power, and running electrical generators. For use in a car, truck, or motorcycle, we also need “the perfect transmission.”
From July 2003 Hot Bikes magazine: “Wayne “Speed” Hanson” Dyno Tuner w/over 40 years of tuning and racing experience.
Since Harleys are big bikes, it’s far more important to tune them for maximum acceleration than it is for top-end power. With a heavy bike like a Harley, you really want to concentrate more on bottom-and mid range performance, since those are the areas of the powerband that are the most important. Faster acceleration and a smoother power curve is always better than chasing a few extra ponies at the top.
Nigel Patrick (Patrick Racing) in American V-Twin Engine Hop-Up and Repair book "
Says he tries to build engines that have really good response between 1500 and 3500 rpm because that's where most of us ride most of the time."
RB Racing
Fuel Injectors
Is an engine that produces 135 hp is better than an engine that produces 125 hp?..Well maybe it is and maybe it isn't. What is the definition of horsepower anyway? The common definition is HP = (Torque x RPM) / 5252. Everyone is so enamored of peak horsepower these days that they will trailer their hot rodded V-Twin from dyno contest to dyno contest searching for bragging rights as to who has the most peak horsepower.
We hate to burst their ego-filled bubble, but in the real world it's the rate of acceleration that wins races, not peak horsepower. Torque is the most important element of the equation and if you can't produce torque in the lower rpm ranges it will take forever to get to the upper rpm ranges where the dyno junkies worship the God of peak horsepower. Every time you grab the next gear your rpms fall and you have to climb that elusive mountain to get back to those so damn important peak power readings. The rate of acceleration from one point to the next is how we judge a vehicle's performance, not how much peak horsepower it makes. The right question isn't peak horsepower but is the search for maximum torque in the rpm band that produces the greatest transient acceleration.
The next time you need a definition of useable power take a look at all the diesels roaming the highways. They are out there for a good reason, they make a bunch of torque right now, not at the top of the rpm band. A typical diesel will crank out 90% of its torque by 2000 rpm!
Tom... there are a few spelling errors in that post. Just thought you would want to know.
- Thread starter
- #6
Good info but remember I talked about choices! Will the tuning guy ask me if I have any preferences like ... say I want max torque from all the gears and I could care less about top end. Can they do that! Or how about wanting the motor very smooth at touring speeds. Can they do that!:xzqxz:
Basically the dyno operator should get your tune to give you maximum power and fuel economy within the abilities of the engine as it is. As far as choice goes, if the operator increases the torque you also get a rise in horsepower.
The mechanical abilities of the engine to make power are determined by your engine displacement, compression, cams, head and intake flow in and how well the exhaust flows out. Adding to that having the right gearing ratio with the driveline to put the power to the ground.
Just remember with our tractor type engines, torque comes first then the horsepower
Also forgot to add, vibration is caused by the imbalance of the flywheels. The Vtwin engine will always have some vibration within the whole rpm range.. The truer the flywheels are the less vibration you will feel within the rpm range it was balanced for.
The mechanical abilities of the engine to make power are determined by your engine displacement, compression, cams, head and intake flow in and how well the exhaust flows out. Adding to that having the right gearing ratio with the driveline to put the power to the ground.
Just remember with our tractor type engines, torque comes first then the horsepower
Also forgot to add, vibration is caused by the imbalance of the flywheels. The Vtwin engine will always have some vibration within the whole rpm range.. The truer the flywheels are the less vibration you will feel within the rpm range it was balanced for.
I saw them also Dave.
- Thread starter
- #10
ok Tour Captain especially on the vibration. I've never actually seen a dyno but I didn't think a trike would fit on one and I also hear that they bring that engine into the 5000 rpm range while tuning. Surprised it doesn't fly apart or damaged in some way. They had me put 1000 miles on it first and I'd say between 700 and a 1000 miles I could see improvement on how it runs and sounds. Because of the cost, I'd like to see a little more TLC during the testing. Again tks. Huel
If you Google a dynojet 250ix you can see what it looks like. As far as the engine flying apart that is a very rare occurance. Your engine can rev higher but since its in a trike most riders don't see those rpms levels very often.
Also for your FYI your ecm has a rev limiter that safe guards over revving it. There are many twin cam engines running into 6500 rpm range with no issues.
A good tune for your trike needs to be in the 5500 to 5800 range for Vtuning and your spark tables. The few times its run in the upper limit will give him the opportunity to get you a good overall tune.
Also for your FYI your ecm has a rev limiter that safe guards over revving it. There are many twin cam engines running into 6500 rpm range with no issues.
A good tune for your trike needs to be in the 5500 to 5800 range for Vtuning and your spark tables. The few times its run in the upper limit will give him the opportunity to get you a good overall tune.
I agreeThumbUp.
Anyone looking for a dyno tune in the Boise, Idaho area. I found a performance shop that can do Trikes. The name is Motor Mayhaem Service & Performance Center in Meridian, Idaho. 208-887-2058 Techs name is Luke.
Are they familiar with Harley, & all the tuners ?
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