Horse Power and Torque

[Adirondack Bill]

I was reading my latest issue of "Motorcycle Consumer News" and  noticed some interesting numbers in their motorcycle performance index. I like this publication because they do not have advertising and usually give you the "real deal" regarding reviews of bikes and bike products because they are not influenced by money from other companies advertising money. They list the horse power for our Valkyrie at 102.3, and torque at  109.5 ft.pounds- (Nice numbers)! The F6B is listed as having 100.1 ponies and 105.24 ft. Pounds of torque. Don't both bikes have the same engine?? The F6B has more weight, but that should not effect those numbers. Why are our numbers higher?

[six2go #152]

It could be the difference in the exhaust. I've heard say that the F6C has a throatier sound than the B. Maybe it's less restrictive and letting the engine breathe better.

[bscrive]

You just beat me to the punch six2go.  I was going to say the same thing. 

I put on a set of Rush pipes with 2.25" baffles and I will be putting on Torq Loopz as well in the next couple of weeks.  I would be interested to see what the HP and torq numbers would be.  Unfortunately, there isn't anyone around that I know of that has a dyno to see.  Maybe next year when I go to Americade I will get them to check it.

[Bill Havins]

I don't know if it makes any difference (I think it does, very slightly) but the throttle bodies on the Valkyries are different.  The A and B Goldwings have a "balancing" pressure regulator vacuum port in the throttle bodies (IIRC).  I wonder if it leads to a "more refined" throttle response which, IMHO, may affect both HP and Torque.  The diameters of the butterflies are exactly the same (Valkyrie vs. Goldwing A/B).

But what the heck do I know?  

EDIT:  Many of the parts in the following parts breakdown do not appear on the Valkyrie.  I have no idea what Honda is doing with this bunch of plumbing but, as above, I wonder if they are "refining" the throttle response.  Someone who really knows will need to explain.  (Sorry about posting Honda's image....).




Bill

[goldstar903]

A big factor is what Dyno was used! For tuning pipes you should have the same dyno for both before and after tunes. Each Dyno will give you a different number. Break-in procedures for seating the rings also have an input.  One of the guys over at F6C forum had a Dyno run of 105.55 Max HP, and 113.15 Max Torque. Another guy installed a PC5 and gutted the stock pipes and attained a 110.58 Max HP, and 118.92 Max Torque. He said it sounded great, but I have a difficult time believing that. So, where did he attain the increase, the PC5, the pipe or both? Is it really worth the expense and  :-\noise level?

[Robert]

Agree with Goldstar on the dyno they are so different. Below are the specs from the Honda site and below that are the converted numbers. I think the dyno runs are a  bit off actually, just my idea though, because the 1500 has almost the same numbers on various dyno runs as the 1800 according to the dyno numbers and this bike is quicker. Too much quicker to account for a small hp gain between the 1500 and 1800 shown in those dyno runs. 

Honda Worldwide site
http://world.honda.com/GoldWing/F6C/spec/index.html

    Type    Liquid-cooled 4-stroke 12-valve SOHC flat-6
Displacement    1,832cc
Valves per cylinder    2
Bore × Stroke    74 × 71 mm
Compression Ratio    9.8 : 1
Max. Power Output    87kW/5,500rpm (95/1/EC)
Max. Torque    167Nm/4,000rpm (95/1/EC)


HP conversion = 116.669
Torque conversion = 123.172

[Adirondack Bill]

Robert, I am sure you have noticed many times over the years that motorcycle manufacturers (inflate) hp and torque numbers to get you to buy their bike. They often give hp and torque numbers at the crank and pass them off as rear wheel numbers. I think the numbers you posted may be crank numbers??- just guessing.

[Robert]

Take a look at some numbers here on an old 1500 post. Bill I dont disagree but something just doesn't add up.

Dyno results  (Read 5629 times)
http://www.valkyrieforum.com/bbs/index.php/topic,8496.0.html

[Verismo]

Interesting catch on the pressure regulator vacuum port, Bill. I have ridden both, and to me, the throttle response feels slightly more attenuated on the B.  Of course the weight, and the way the transmission responds to the weight, affects this, but I wondered if there might be more to it than that.

[Bill Havins]

Verismo, I "discovered" the extra plumbing when I ordered a 2015 F6B throttle body to make it easier to install my Rostra Cruise on my Valkyrie (I wanted the "lost motion pulley" on the end of the butterflies shaft).  I ended up capping the third vacuum port and the set up works swell.  But I wondered about the pressure regulator.  Haven't seen/heard an explanation for it, but I haven't looked very hard to find one.

Bill

[Verismo]

I read that post and thought it was very helpful.  You are a much better wrench than I am(probably most guys on here are, I have to Google everything) and I love reading that stuff.  It would be interesting to confirm whether or not the pressure regulator affects throttle response and to what degree, but I certainly don't have the know-how.

Jason

[Robert]

Are you guys talking about #5 on the pic? That is the pressure regulator. It doesn't appear to be on the our bikes, which is interesting. The fuel pressure regulator does just that regulates fuel pressure. The vacuum line to it is for the purpose of making the fuel mixture richer on acceleration. Kind of interesting the differences between the Goldwing and the Valkyrie and there seem to be many in the fuel system. The fuel pumps are totally different there is no fuel pressure regulator on the Valkyrie and there are additional switches on the Goldwing than the Valkyrie. That would mean that the computer the programing and the controls are totally different on the Valk than the wing as for the fuel injection. Guhl said that the programing on our Valks is different than the wings and as I look I begin to understand why. Technically it would make sense that the wing would have more controls on it since fuel regulation on cruising would be important. Especially to give the leanest mixture possible on cruise yet to have the getup and go on full power acceleration.

Thanks guys another interesting tidbit that will probably go nowhere. 

[Bill Havins]

The parts breakdown I posted above is a "red herring" - it has nothing to do with published differences in HP and Torque for the Valkyrie and F6B.

The pressure regulator in the image simply ensures that the fuel pressure in the injection system remains constant.  I believe the pressure regulator for the Valkyrie is part of the fuel pump inside the tank (don't know for sure because it isn't "called out" in the parts breakdown).

EDIT:  I just went through the service manual.  The pressure regulator is, indeed, part of the fuel pump assembly.  It fits in a port in the fuel filter.  So, now I know where it is. 

#2 in the image (both left and right sides) are the fuel rails; the Valkyrie has them, too, but they are buried on another page of the parts breakdown.  These rails distribute fuel to the injectors (three injectors per side of the engine; one injector per cylinder).

Now, there is no vacuum line to the pressure regulator on the Valkyrie.  So, the pressure regulator functions "independent" of the speed of the engine.  That should not cause a difference in HP/Torque because the pressure of the fuel rails should always remain constant whether the engine is idling or running all the way up to the rev limiter.  I believe the plumbing differences, then, are simply indicative of the engineering differences because of the differences in fuel tanks on the two bikes.

Bill

[Robert]

Bill without knowing why the systems are different in the wing and the Valk we really dont know if this would contribute to a different hp/torque. Its not quite as simple as comparing apples to apples as you say and in fact the pictures you posted were not red herrings at all but show significant differences in the fuel injection system of the wing and the Valk.

 The fact that the Valkyrie has a different style regulator or fuel system is interesting enough to look into the differences and here are a couple of things for thought.

 The wing has a rising rate fuel regulator which is why the vacuum line connected to it in the fuel rail. The Valkyrie does not have one in the fuel rail but in the pump casing. This regulator on the wing raises the fuel pressure when the throttle is wide open so its not a constant pressure. There is no provision for this fuel pressure change or regulator on the Valkyrie.

Now because of this it could affect hp, but at very least it shows a different, cheaper, more easily programed fuel injection setup on the Valk, maybe designed with different riding styles in mind.

 The fact that Honda decided to use a different system on the Valk is interesting. It would also require a modification to the fuel curves or very least to fuel calibration. I wouldn't know why they couldn't have used the wing fuel injection on the Valk either.

Fuel pressure on the wing is 50 with the vacuum line removed and on the Valk its 47-55 psi. The part that's missing in the Service Manual is the "Normal" operating pressure with Vacuum Applied. From what I have found it should be around 40 to 42 PSI.

This lower fuel pressure with the same injectors would require a longer pulse width on the injectors to keep a 14 to 1 ratio. But I suspect they may even run it a bit leaner on cruise. The wing with the raising rate fuel regulator could jump immediately from a lean cruise to a rich full acceleration in a split second.

The wing also has a fuel return where our Valks do not. That though could just be a matter of design since the wing has the fuel pressure regulator in the rail, where the Valk has it in the fuel filter assembly.

The injectors are the same for the wing and the Valk.

More than likely the Valk was considered a full power cruiser and gas mileage was not paramount in design. But the wing has to get good milage and this different system would do the trick. Its more expensive, more precise and able to give Honda more control over mixture. That could translate to HP/Torque.

I knew what your pictures were, that is what interested me. The first idea I got that something is different was the vacuum line and the micro switch I found on other wing throttle body diagrams. It then got me to do a bit of research on why put a variable fuel pressure regulator on the wing and not the Valk. 

[Bill Havins]

[snip]....and the micro switch I found on other wing throttle body diagrams....[snip] 

I believe that, when the cruise control is "on," that microswitch allows the rider to roll the throttle completely forward (i.e., "shut off" the throttle) and the cruise control will turn off (the microswitch "opens," removing power from the cruise, so-to-speak).  That's if I am remembering the schematic correctly.

I pulled the microswitch off of my replacement throttle body.  I did not want to do the wiring that would allow it to work with my Rostra Cruise - it seemed redundant to the brake switch disengage, and the toggle switch I have on my handlebars.

Regarding the pressure regulator, plumbing makes my head hurt after a while.  You are welcome to chase that to ground - I'm going to go get a glass of iced tea. 

Bill

[Robert]

Regarding the pressure regulator, plumbing makes my head hurt after a while.  You are welcome to chase that to ground - I'm going to go get a glass of iced tea. 

Bill

Enjoy your tea, its one of the things I do, I have been down that road many times. 

[Verismo]

I swear, one of the advantages of owning  a Goldwing or Valkyrie is the quality of conversation you can have on the forums.  The above tidbits are really interesting and I would not have known where to find this info on my own.  What I mostly have are my intuitions and impressions about the different feel of the B and the C.  The throttle response of the B seems more attenuated at most rpm's, there is more of a roll-on, roll-off sensation.  This effect seems to diminish some the higher the speed and the more you hit the throttle. The C is more abrupt, especially at lower rpms.  I attributed this to the weight difference, which I'm sure is a factor, but the differences in fuel systems seem like they might also be factors.

Jason

[Robert]

I found a brochure for Honda and according to the numbers in the brochure the F6C has less HP than the B but with the same torque numbers. Still at 87KW and 167nm for the F6B and 85KW and 167nm for the C.
F6B/Goldwing
Motor:
 Vloeistofgekoelde 4-takt, 12 kleppen, SOHC, 6-cilinder boxer
Cilinderinhoud:
1.832 cc
Maximumvermogen:
87 kW (118 pk)/5.500 tpm (95/1/EC)
Maximumkoppel:
167 Nm/4.000 tpm (95/1/EC)

F6C
Motor: 
Vloeistofgekoelde 4-takt, 12-kleps SOHC 6-cilinder boxer
Cilinderinhoud:
1.832 cc
Maximumvermogen
85 kW (116 pk)/5.500 tpm (95/1/EC)
Maximumkoppel
167 Nm/4.000