| Author | Message | ||
     Augustus74 |
What are the hp ratings for the Lightning/Firebolts 9 and the 12? Are all years the same? | ||
| Froggy |
92HP for all XB9 models, 103HP for all XB12. | ||
| Augustus74 |
Thanks! | ||
| Augustus74 |
What about the tq.? | ||
| Vospertw |
I thought the 12 was 84 and the 9 something like 70? | ||
| Reepicheep |
There are three different measures of power: 1) RWHP. This is (kinda) the one you can trust. It is the power of a real live bike on a real live dyno as put out through the rear wheel. Many dynos error high, but at least its a real measure. That will be the lowest number you see, and I expect a 12 would be something like 85-90HP, and a 9 to be 70-75HP. I think my 9sx dyno'd at 76 HP with race ECM and stock exhaust... the race ECM added power simply be raising the redline (and lowering reliability). 2) Crank HP. This is the horsepower of the motor on a test stand where the crank directly drives the dyno, and everything else is set up to be as good as it can possibly be. That is the 92 or so HP for the 9 figure, and 101 HP for the 12 figure. There are official SAE prescribed ways to do these tests, and they also generally read a little optimistic. 3) HP Measured at the Brochure. This is the most common measurement, and is the same one used for "dry weight". There has been a steady historical fantasy inflation factor applied (mainly by the Japanese bike makers) over the years. It's pretty much fantasy, but is fantasy grounded in a sort of common shared fudge factor that grows over time. This is the figure you see quoted by sales guys and posers. Hope that helps.  (Message edited by reepicheep on February 18, 2011) | ||
| Terrys1980 |
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| Swordsman |
Just a note, don't forget the 9's rev quicker than the 12's. My Ss revs slooow. Nothing to do with the HP, but another difference to consider in the "feel" of the engines. rrrrrrrrrRRRRRRRRAAAAAAAWWWWRRRRRRR  ~SM (Message edited by Swordsman on February 18, 2011) | ||
| Andymnelson |
In addition to the slower revving... Using 92 hp for the 9 and 103 hp for the 12, the 9 has 10.67% less power than the 12. The 9 also has 11% steeper gearing than the 12. Those 2 numbers combined with the rev-happiness of the 9 help you to see why those of us who own both motors love their 9s! | ||
| Glitch |
I replaced engine speed with time. Dyno data courtesy of American Sportbike.  Note the reason it looks like the 9 took longer to get to peak power is because it does, it has a higher rev limit. | ||
| Reepicheep |
Great idea Glitch! Nice informative graph. I had my 9 against 12's at mid ohio, and we would start even and go WOT from 2nd gear to as fast as you could go... The 12's would gain on me at a relative normal walking speed. Definitely faster, but not dramatic. My 9sx and 12x ownership overlapped for a while. The big difference I noticed was where the power is, not the total power. Both bikes did what I needed when I needed it, the Uly (12) just did it without having to be wound out as much. On the downside, the Uly eats tires much faster than the 9 ever did, and I am guessing 9's have significantly longer longevity if ridden hard (due to the shorter stroke). | ||
| Delta_one |
the nine doesn't feel like it has as much "lump" at idle either. I test rode 12's exclusively at first because I wanted the larger engine but I found a nice clean XB9Sl with all the right mods on it and for the right price and when I rode it I fell in love with the nine engine on after only a few miles. it just feels more lively to me. | ||
| Augustus74 |
Wouldnt the 12's torque make them feel more enjoyable on the street? | ||
| Froggy |
In my opinion, yes. The XB9 in my opinion, feels lacking. It reminds me of my Blast, except without the good fuel economy. | ||
| Reepicheep |
There is no such thing as torque if you are moving, there is only power. Terry's plot above tells the entire story. A 9 at 3800 RPM is making 40 HP. A 12 at 2800 RPM is making 40 HP. Both will feel identical, except for the frequency you feel from the vibration of the motor. A 9 has to rev further and still makes less power. But if you aren't on a 12 at near redline (which isn't a happy place for a 12 to be), the 9 can match it exactly by just revving higher. And as a happy 12 owner right now... I have to say... a 9 at 7200 RPM howling through an open airbox on a beautiful spring morning is an amazing and wonderful thing... Having now owned a 9 and 12, I'd pick the 9 with an 1150 bolt on kit. | ||
| Terrys1980 |
FYI - Those plots were from American Sport Bike's exhaust shootout. | ||
| Augustus74 |
Torque does matter when moving. If your rolling along under 4k rpms and hit the throttle, the bike with more torque will accelerate faster. I was talking about "street" as being more everyday/commuting/around town type of driving. Though a 9 with an 1150 kit may be very interesting. | ||
| Sloppy |
Ah, discussions on torque and power... here comes the can of worms... Torque is a measurement of energy. Horsepower is a measurement of power, or energy per unit time. Torque "feels" like a steady push (like how gravity pulls you to the ground - it's steady) Power "feels" like a change in a push or a hit (like how you jump up from the ground) So what does this mean? The bike with more power will always accelerate faster (as long as your tires don't break traction) since it factors in both torque (energy) and engine speed (how quickly the energy is delivered). This is the reason why twins are given a displacement advantage over 4's. For the same displacement, twins produce more torque but not as much power so they need to be given additional cubic inches to have similar power so they'll be able to compete. The only reason I would consider a smaller displacement engine is if there is a large difference in weight... | ||
| Natexlh1000 |
Torque is the measurement of force Can of worms untangled: http://en.wikipedia.org/wiki/Power_%28physics%29 | ||
| Sloppy |
Let me open the can again: Force and torque are not the same. Force = mass * acceleration. Units are lb or newton. Torque is different depending upon what you are using -- think about this: 1 lb ball that is pushed 1 foot = 1 ft-lb. 1 lb ball on the end of a 1 foot bar = 1 ft-lb. The tricky thing here is one is a description of moment and the other a description of energy even though they both share the same units... Worms anyone? | ||
| Reepicheep |
Most people do have it wrong. Including Carol Shelby, in at least one quote I saw attributed to him. A motor making a little less torque but turning a lot faster makes more power, and power is what determines both speed and acceleration. Horsepower is measured by a Dyno, torque is calculated. That should be a big clue right there. Torque is calculated to be at the crank. 100 foot pounds at the crank. So picture that. Now say that crank can rotate at 100 RPM maintianing that 100 foot pounds of torque. You gear your bike accordingly, and away you go. Now say you figure out a way to get that 100 foot pound crank to be able to rotate at 10,000 RPM, but still maintain 100 foot pounds of torque the whole time. Your gearing changes completely, Can't you see that a 100 foot pound motor rotating at 100 RPM would be feeble to that same 100 foot pound motor rotating at 10,000 RPM? That's power... torque times RPM (with some units conversion constant multiplier). | ||
| Glitch |
All I know is for me, I'm faster on the Nine. I can be on the gas longer and sooner, and the brakes less. For me, the Twelve rules right off the line, and towards the top of the midrange, with the rush a freight train. The Nine on the other hand feels to me like an electric motor pushing steady from start to finish. Suits me just fine. | ||
| Kenney83 |
I have a 2003 XB9, My friend I ride with has a 2009 XB12. We have lined them up multiple times to see who is faster. He usually has the jump on my, I would assume because of the torque, but once my nine starts revving up (and it does so quickly) he no longer pulls on me. He needs to shift before I do. So while he is shifting I am still in the gas accelerating. By the time we back out of the throttle we end up almost being even. When he does pull on me it is never more than a bike length ahead. This is just my experience with the nine and twelve. | ||
| Reepicheep |
Thanks for the great illustration Kenny! If it was torque, he would keep pulling on you. It is horsepower. What is happening is that once your 9 is revving faster then his 12 (making less torque, but making more RPM's) the horsepower of both bikes at the rear wheel equalizes. If you both ran out to redline, he should gain on you again there. But in between, a 9 is just as fast as a 12 if you are revving it a little faster. | ||
| Blake |
Bill, >>> Horsepower is measured by a Dyno, torque is calculated. Some dynos do measure torque, a "brake" measures torque and from that and engine speed derives HP. Even on inertial dynos, the HP is a calculation based on measured changes in the time intervals for drum rotation. So all an inertial dyno actuall measures is the time for each revolution of the drum, and if desired engine speed based on ignition sparks per minute times two. I agree that all else being equal, higher HP rules in most any contest of speed. | ||
| Blake |
>>> Just a note, don't forget the 9's rev quicker than the 12's I hear that a lot. Not sure what it means other than one bike has a lower overall drive ratio than the other. A lower drive ratio will allow it to rev faster. All else being equal, the bike with the most power will rev faster during acceleration. | ||
| Terrys1980 |
Blake...one of the main reasons the 9 revs up faster as it has a shorter stroke. The piston in the 9 does not travel the same distance as in the 12. | ||
| 1324 |
Simple solution that Blake alluded to and most other omit (historically, not this thread in particular): Put the 9 primary gearing on your 12. Long stroke and all, it will rev - fast! With the exception of first gear, I never personally notice the shorter redline on the 12. Miles of smiles! | ||
| Buellblastrider |
yes we are talking what 400 rpms difference? (04-07 12's went to 6800 rpms) I have 2 12's and wouldn't have it any other way. The nine seems to be the better motor to build but the 12 is good if your only going to do bolt ons. I live in a mountainous area with tight corners where that instant torque off idle is great. If I wanted to ride a bike the needed to be wound out I'd ride my girlfriend GSXR. Nothing against you nine guys, its just for my riding style and purpose the 12 is the better weapon | ||
| Mad_matt |
NRHS 1050 on me 9 next winter.....yes indeeedy |
