[GR8RALLY]

How does Honda calculate the HP rating for the VTX? The 2003 VTX 1800R from what I can tell has 106 HP and 120 lbs of torque. Are these ratings at the rear wheel, or is it like with some car manufactures the "engine/flywheel" numbers? The reason I ask is that the previous owner of my bike had it dyno and it was rated at 112 HP with the following upgrades; aftermarket Pro-Charger, V&H Big Shot exhaust and PCIII mapped aggressively. Do the numbers sound about right?:hmm2:

 

[Spoiler]

Sounds a little high to be that much at the rear wheel

 

[bryanova]

i agree, Spoiler, but i think the earliest 1800 models were sporting a few more HP than later models. For example, my brother's 02 1800 was very agressively dyno tuned with bubs, no baffles, powercommander III usb and i think his best was 114 hp. I do know it ran like the proverbial raped ape :mosh: and why not?

 

[Spoiler]

i agree, Spoiler, but i think the earliest 1800 models were sporting a few more HP than later models. For example, my brother's 02 1800 was very agressively dyno tuned with bubs, no baffles, powercommander III usb and i think his best was 114 hp. I do know it ran like the proverbial raped ape :mosh: and why not?

Bry, you could be right, ...it's possible, ...it's probable, and it's about time, :mosh: and why not? :bleh:

 

[Got 1800?]

Bry, you could be right, ...it's possible, ...it's probable, and it's about time, :mosh: and why not? :bleh:

yep, almost 5 O'clock! :beer: (although it is 5 O'clock somewhere) :drunk::cheers::mosh:

 

[Bassdude404]

The published HP and torque numbers were taken at the crankshaft, not the rear wheel...

 

[bryanova]

hp numbers published by who, Bill? Also, if thats the case, the 1300's are not putting out much hp as i have seen their hp published at 56. That's very low for a 1300cc bike, even if it is a sohc v-twin.

 

[Bassdude404]

hp numbers published by who, Bill? Also, if thats the case, the 1300's are not putting out much hp as i have seen their hp published at 56. That's very low for a 1300cc bike, even if it is a sohc v-twin.

Honda dyno'd the engines at the crank,. and released that info to all the magazines, etc....At you're right, 56 hp isn't much...But it's a low-reving V-twin, not a screaming inline-4...With a V-twin, it's all about torque..That's what moves you off the line and up through the gears....Honda's very own CBR600, at less than half the displacement of a 1300, will put a major spanking on a 1300....

 

[00 Doc]

Horsepower = Torque x RPM/5252

Torque is the force that can be measured with a dynometer. The trouble is that there are several factors that must be applied to achieve a comparable and repeatable results between dynometers. Also the type of dynometer, whether inertia, hydraulic, or electric have different variables.
Inertia Dyno: These extrapolate rear-wheel power output by analyzing the dyno drum's acceleration rate using a sophisticated accelerometer and computer software. Hydraulic Dyno: Like most engine dynos, the hydraulic or water-brake chassis dyno relies on a constant speed brake or absorber coupled with a rotor with a rotating element and a stationary element. The rotor elements generate braking force using water or hydraulic fluid to absorb or match the powertrain output. Usually a strain gauge measures the torque reaction between the rotor's rotating element and a stationary element.
Electric or Eddy-Current Dyno: This type of dyno controls the brake/absorber using electric current instead of fluid, measuring torque output and calculating power based on a strain gauge. Electric current provides much more precise control and minimal spool-up lag time, but you need a gonzo electric supply and the dyno itself is more expensive than other types.
The horsepower and torque numbers are altered with a weather correction factor. The raw power figures are multiplied by the correction factor, giving you the ability to adequately compare engines tested in varied conditions of temperature, pressure, and humidity. Because engines make more power at oxygen-rich sea level locations than they do atop the Rocky Mountains, or in dry and cool climates as opposed to hot and humid ones, it's necessary to have a formula that takes into account these conditions to level the playing field between different dynos, or even different test days on the same dyno.
The Society of Automotive Engineers have developed several correction factors for dyno testing, and it's important that if you compare numbers from one dyno with the next that the factor be the same.
The SAE J1349 correction factor, utilizes the following numbers for reference: 77 degrees Fahrenheit, 29.234 in-Hg barometric pressure, and zero percent humidity.
The other correction factor, SAE STD factor, references 60 degrees Fahrenheit, 29.92 in-Hg, and zero percent humidity.
Using the STD factor usually pushes the raw power numbers approximately 4 percent higher than the J1349 correction factor.

I would avoid comparing results from different dynos, and stick with one and just compare results using the same correction factors.

Interesting article on this at: http://www.hotrod.com/techarticles/general/hrdp_1103_chassis_dyno_testing/viewall.html#ixzz1U0f9Jfg2
​

 

[gillahoon]

I read also 106hp 120 foot pounds on 07 f

 

[GR8RALLY]

So is the correct HP rating for the 1800 R in 2003 106 at the crank? So does anyone know what the HP would be at rear wheel utilizing the inertia dyno. Just trying to validate the so-called 112 HP inertia dyno rating the previoues owner claims the bike has, yet he hasn't been able to locate dyno sheet. Im no HP junkie, but knowing the actual claimed HP from Honda on a stock 03 1800 via Crank or rear wheel would be nice to know.

 

[Bassdude404]

So is the correct HP rating for the 1800 R in 2003 106 at the crank? So does anyone know what the HP would be at rear wheel utilizing the inertia dyno. Just trying to validate the so-called 112 HP inertia dyno rating the previoues owner claims the bike has, yet he hasn't been able to locate dyno sheet. Im no HP junkie, but knowing the actual claimed HP from Honda on a stock 03 1800 via Crank or rear wheel would be nice to know.

Can't answer your question directly...But generally a rear wheel dyno numbers are gonna be lower than a crankshaft dyno, due to power loss through the transmission and the rest of the driveline....That's why car/bike manufacturers use the crankshaft numbers when advertising their vehicles...Bragging rights at bench racing sessions...lol...

 

[billcarr]

The only number i read consistently (and that not often) is 89hp at the rear wheel on an 1800.

 

[whiskeyrockr]

Honda dyno'd the engines at the crank,. and released that info to all the magazines, etc....At you're right, 56 hp isn't much...But it's a low-reving V-twin, not a screaming inline-4...With a V-twin, it's all about torque..That's what moves you off the line and up through the gears....Honda's very own CBR600, at less than half the displacement of a 1300, will put a major spanking on a 1300....

it's like trying to explain the wheelbase of a vehicle which is not from the front of the front tire to the rear of the rear, it's from the center of the front wheel to the center of the rear wheel (unless of course you're talking about a tandem axle unit, then it's from the center of the front wheel to the center of the 2 wheels--inbetween the 2 wheels)...it's almost useless to explain because people are gonna argue and it's a pointless discussion :cheers:

 

[GR8RALLY]

Upon further research on various forums (including this one ), its seems that the stock HP at the wheel is approximately 86 and Torque is 110. Many other members with similar add ons either estimate or had dyno results in the ball park of 98 HP. The 112 I was told still could be correct depending on which dyno, etc :icon_blah :icon_blah was performed. Thanks for the responses, now I'm off for a cruise with a buddy! :choppersm

 

[dugsamin]

All I know is it's more than enough to move my considerable heft around (372lbs). So far I've lost 31 lbs, down from 403. If I hit my target weight of 240 it'll be almost like strapping on another 60-70 hp. That's the cheapest performance mod in history I believe. Lol:drunk:

 

[GR8RALLY]

I hear ya Dale, down to 195, lost 60lbs in the last year. Talk about increased performance and not just the bike.....LOL!

 

[dugsamin]

That's great Rod. Keep up the good work.:drunk:

 

[CheeseMan316]

Late comer to the conversation, but 2 months ago I had my 2006 1800C dyno'd and tuned and it put 98HP to the rear wheel. I don't know what kind of dynomometer, and I don't remember the peak torque rating. That is with HC, PC3 and Bub Jug Huggers.

 

[Spoiler]

Upon further research on various forums (including this one ), its seems that the stock HP at the wheel is approximately 86 and Torque is 110. Many other members with similar add ons either estimate or had dyno results in the ball park of 98 HP. :choppersm

That sure sounds like its probably more accurate right there.... That's what I have seen in several places as well..

atriot: