Simulated FJR vs C14 race

[UselessPickles]

I'm slowly making progress on an application that will allow one to get meaningful performance data/comparisons about motorcycles based on torque chart data along with other critical info (weight, drag coefficient, gear ratios, etc.). Today, I worked on simulating acceleration over time. What better way to show off my work than with a simulated drag race between an FJR and C14?

So we're looking at a 2008 FJR vs a 2011 C14 (nothing has really changed since 2008 on the FJR, so a fair comparison). First, here's what most people and magazines focus on:

The good ol' torque and horsepower charts. It's hard to do any meaningful comparison between torque/horsepower charts of vehicles with different weights and transmission setups, but that doesn't stop people from endlessly debating old wives tales about torque vs. horsepower, and "where torque really matters", etc.

Now for a meaningful comparison. I simulate a 1/4 mile max acceleration run of both bikes. The calculations assume the weight of me on both bikes, a perfect launch with 100% throttle and the clutch modulated perfectly to hold the engine steady at each bike's peak torque RPM the entire time, perfect traction, and crisp gear shifts at the best possible times for max acceleration on each bike that are executed in 0.25 seconds. Essentially, this is the theoretical limit for best possible performance on these bikes.

And the winner is...

... (drum roll) ...

The C14!

C14: 10.71s @ 127.7mph; 0-60mph in 2.6s

FJR: 10.79s @ 126.7mph; 0-60mph in 2.5s

The C14 was ahead of the FJR by 13.9 feet at the end.

NOTE: The torque data used was SAE-corrected (sea-level, some standard pressure, cool temperature, low humidity, etc), so these are simulated best-possible corrected 1/4 mile times for these bikes.

But that's not the full story. We can see exactly how it goes down by looking at graphs of various data. Here's a graph showing how both bikes accelerate over time. The gear shifts are quite obvious, and you can even see how the bikes slow down slightly while shifting due to drag.

And here's a look at the distance between the bikes throughout the race. The FJR launches ahead initially, but the C14 takes the lead as the FJR shifts into 3rd gear.

Isn't that much more interesting and informational than trying to compare torque or horsepower charts?

So who's going to try to work toward the theoretical best possible 1/4 mile run of 10.79s @ 126.7 mph on a stock Gen II FJR?

 

[azitlies]

Great info Pickles. Well done!

Absolutely confirms my contention that there's no reason whatsoever to give a rats about the exceptionally minor differences between the major contenders in the sport touring category. They are all good bikes... ride the one you like the most.

 

[03HiYoSilver]

Now it would be a Fair Comparison if you put in the 100CC (or a loss of about 8%) handicap on the FJR...

Then the numbers with this tight gap would be reversed and in Favor of the FJR.

all in all nice work you have done with your Charts.

 

[wfooshee]

Why? The FJR is 100 CCs smaller. Why factor in a "possible" FJR1400 or C13? They are what they are, and he showed a theoretical run between them.

Factoring a displacement increase for the FJR or a reduction for the C14 would be conjecture, because any guess at the curves from that would be just that; a guess.

 

[escapefjrtist]

Interesting comparison UP, thanks for taking the time to put it together. Confirms why the FJR is my current choice of ST.

I'd like to know where y'all are getting a 100cc difference in engine size. Last time I checked 1352 - 1298 = 54...new math? :blink:

--G

 

[HotRodZilla]

Great info Pickles. Well done!

Absolutely confirms my contention that there's no reason whatsoever to give a rats about the exceptionally minor differences between the major contenders in the sport touring category. They are all good bikes... ride the one you like the most.

Lots of us are in agreement on this issue. Real-time, on a road with human riders on them, any race would come down to the rider...I wonder how the C-14's bigger size and weight would affect this same race through the twisties...

I only ask, 'cuz they fall back every time, but I pass them too fast to figure out what year they are. Oh well...

Nice job Pickles.

 

[UselessPickles]

Real-time, on a road with human riders on them, any race would come down to the rider...

Yup. The simulated performance of the C14 does not show nearly as much of an advantage as the torque/hp charts would make most people believe. The FJR actually has the advantage up to freeway speeds, so one could argue that the FJR is actually faster in the practical world (public roads, not excessively speeding).

I wonder how the C-14's bigger size and weight would affect this same race through the twisties...

I'd like to see a full-throttle 1/4 mile race on a twisty road It would be amusing to watch bikes flying off the last corner at 130mph (if they even make it that far).

Theorizing on which bike would win a "real" race with curves is probably more useless than trying to come to conclusions based on tq/hp charts alone. There's so much more that comes into play when you add corners that you could probably find 2 different sets of corners where the FJR would win on one set, but lose on the other. You have to take into consideration braking ability, whether corner speeds tend to sit in one bike's power band better than the other, whether a corner's radius/length would cause the rider to purposely enter the corner in a higher-than-optimal gear to avoid shifting mid-corner, and way more additional factors that I don't even want to think about.

 

[MCRIDER007]

The FJR actually has the advantage up to freeway speeds, so one could argue that the FJR is actually faster in the practical world (public roads, not excessively speeding).

I have had a C14 and a FJR for the last 4 years...and that is one comparison between them I would never make. I can think of several reasons to ride/own a FJR rather than a C14 but drag race performance is not one of them.

 

[supertankerm60a3]

Great work pickles. Are you an engineering student? You are certainly showing promise. How long do you thing it will be before you are able to figure aerodynamic drag into your equations?

 

[n7myr]

my dog is smarter than your honor student

good info thanks for sharing

looks to me like most of us are not good enough riders to even tell the difference

I have had both and to me they are Ford Chevy

the FJR is a great bike and the Concours is a great bike with newer tech

we ride what we like and we brag that what ever it is, it is the best that was ever made

they all have pro's and con's some big some small

I have always said the world would be more screwed up than it is now "if we all liked the same thing"

 

[GeorgiaRoller]

C14: 10.71s @ 127.7mph; 0-60mph in 2.6s

FJR: 10.79s @ 126.7mph; 0-60mph in 2.5s

I'm not a drag racer but these numbers seem to be pretty accurate from what I've seen posted on the internet. YouTube has a FJR 1/4 mile video that had pipes, FI controller & intakes and his numbers were almost exactly the 10.79s @ 126.7mph that you posted for a stock FJR with a perfect launch/shifting (which is nearly impossible to do in reality). So with the extra performance & human error these numbers look about right.

 

[UselessPickles]

I have had a C14 and a FJR for the last 4 years...and that is one comparison between them I would never make. I can think of several reasons to ride/own a FJR rather than a C14 but drag race performance is not one of them.

The point of my post wasn't really to try to say one bike is better than the other, or that pure acceleration is the best way to compare bikes. It was more to show that torque/hp curves alone do not provide nearly enough info to come to any conclusions about how one bike would compare to another in pure acceleration. Same with power:weight ratios, 1/4 mile times, etc.

There is some very general info you can get from all the typical info that magazines include in their articles and that people debate endlessly about on forums, but it's possible to get some real meaningful comparisons if you just convert that torque curve into real acceleration info by incorporating the bike's weight, gear ratios, etc.

Great work pickles. Are you an engineering student? You are certainly showing promise. How long do you thing it will be before you are able to figure aerodynamic drag into your equations?

Thanks I'm just a software engineer that likes physics and motorcycles. I already do have aerodynamic drag in there (otherwise the calculated 1/4 mile times would be WAY optimistic). You can see in the speed vs. time graph that the bikes slow down slightly while shifting due to drag. I used reported top speeds of the bikes to determine their drag-area coefficients.

C14: 10.71s @ 127.7mph; 0-60mph in 2.6s

FJR: 10.79s @ 126.7mph; 0-60mph in 2.5s

I'm not a drag racer but these numbers seem to be pretty accurate from what I've seen posted on the internet. YouTube has a FJR 1/4 mile video that had pipes, FI controller & intakes and his numbers were almost exactly the 10.79s @ 126.7mph that you posted for a stock FJR with a perfect launch/shifting (which is nearly impossible to do in reality). So with the extra performance & human error these numbers look about right.

Did it happen to be

from a youtube user named "UselessPickles"?
That's a 10.824s @ 127.66mph. But, like you said, that is a modded FJR. My simulated FJR drag race is based on the torque curve of a stock bike, so it's not really a valid comparison. I also launch at only about 4000 RPMs instead of the optimal 6800 RPMs that was used in the simulated race, so my real run could definitely be faster (I'd like my clutch to last a long time, and I'm kinda scared of launching that hard). I would like to get a dyno run with my bike in its current state so I could figure out its theoretical best 1/4 mile run.

 

[MCRIDER007]

The point of my post wasn't really to try to say one bike is better than the other, or that pure acceleration is the best way to compare bikes. It was more to show that torque/hp curves alone do not provide nearly enough info to come to any conclusions about how one bike would compare to another in pure acceleration. Same with power:weight ratios, 1/4 mile times, etc.

There is something wrong with your assumptions and the resulting charts. When calculating pure acceleration you should use foot pounds of energy being delivered to the rear wheel (torque times gear ratio) to determine shift points...which is usually redline or slightly past redline. The FJR and C14 have pretty similar gear ratios but the C14 has a huge advantage in torque above 7500 rpms...where it is going to be the entire time after shifting into second gear. It also has a redline 1500 rpms higher than the FJR giving it a even greater advantage in energy being delivered to the rear wheel for much of the contest. The FJR is going to be very competitive until it has to shift into second gear and then the party will be over...and that is exactly what happens in real life when doing first gear roll-ons at 20 mph (which takes the rider's ability to launch from a dead stop out of the equation).

 

[UselessPickles]

There is something wrong with your assumptions and the resulting charts. When calculating pure acceleration you should use foot pounds of energy being delivered to the rear wheel (torque times gear ratio) to determine shift points...which is usually redline or slightly past redline.

My shift points are determined by finding the speed at which the next higher gear begins to produce more acceleration than the current gear (I think that's what you're describing). On several sporty bikes that I've processed so far, the shift point is only at redline for the shift from 1st -> 2nd. The remainder of the shift points move progressively lower in RPMs.

I explain it in detail with fancy graphs in this thread: https://www.fjrforum.com/forum//index.php?showtopic=142341

The FJR and C14 have pretty similar gear ratios but the C14 has a huge advantage in torque above 7500 rpms...where it is going to be the entire time after shifting into second gear. It also has a redline 1500 rpms higher than the FJR giving it a even greater advantage in energy being delivered to the rear wheel for much of the contest. The FJR is going to be very competitive until it has to shift into second gear and then the party will be over.

Without actually calculating everything out to see exactly how each bike accelerates, it is pointless to mention higher redlines, similar gear boxes, which bike has more torque at what RPMs, etc., and try to come to conclusions. That is exactly the point of what I did.

There are differences in the gear boxes. There are differences in primary/secondary reduction ratios. There are differences in weight and aerodynamic drag. Too many variables to just look over the numbers and come to a conclusion. My results are based on factoring in all of these variables and actually calculating exactly how fast each bike can accelerate at any given speed, and when you should change gears for max acceleration.

My results will not quite match your 20mph roll-on race results for a couple reasons. The most obvious is the potential for human error (did both riders start at the same time? did they shift at the optimal shift points?). More importantly, you are starting at 20mph with the clutch fully engaged. My results are based on starting from 0mph and slipping the clutch for quite a while (beyond 20mph). When you open the throttle at 20mph with the clutch fully engaged, you will not accelerate as fast as a proper launch through 20mph, because you will not be using the peak torque of the engine. Also, the FJR's biggest advantage over the C14 is in the 0-60mph range. Starting at 20mph, you've taken away quite a bit of the FJR's advantage.

I'll make some graphs for a 20-127mph race (no clutch slipping) this evening for comparison to the 1/4 mile results.

 

[NMRoadRunner]

I would not argue with your data, but add a couple of turns and it's a different out come at the finish! :yahoo:

 

[UselessPickles]

Here's another graph based on the same data that was used for my simulated race.

This shows that the FJR can accelerate harder than the C14 through much of 1st gear. Even more significant for a drag race is that its peak acceleration in 1st gear is significantly higher than the C14's peak acceleration. For an optimal launch (which I simulated), you slip the clutch the right amount with 100% throttle so that your engine is at peak torque (and therefore, you are at peak acceleration) from 0mph all the way up to the speed at which peak acceleration occurs with a fully engaged clutch.

In a drag race launch, the FJR will accelerate faster than the C14 all the way up to about 53mph. At that point, the FJR is already going faster than and has traveled further than the C14, which is why the C14 doesn't catch up until the FJR is at about 88mph (I think the FJR needs a flux capacitor).

Again... the point of all of this is not whether or not such a comparison of raw acceleration is meaningful for these particular bikes, or to claim one is better than the other. It's just to generally point out that if it comes down to comparing raw acceleration between two bikes, all the stats about the bikes (tq/hp charts, weight, gear ratios, etc.) must be combined together to calculate actual acceleration. Trying to compare tq/hp charts directly and mentally factor in weight and other factors will most likely give you incorrect conclusions. This is why arguments over torque charts and which bike would be faster never come to an a consensus. Each person cites different generalizations to back up their claims.

If you want to know which bike will take the lead off the line, and whether the other bike will eventually pass (and when/where), the information is available to figure it out. No need to guess based on torque charts. How about determining "real world" acceleration from an "around town" speed in a typical gear for cruising at that speed (without downshifting)? It can be calculated and directly compared between bikes. I'm surprised that the bike mags haven't figured this out. Imagine if their sportbike shoot-out articles had more meaningful graphs like this.

 

[JasonB]

Would be interesting to see the drag race between multiple FJR's at different rider (or load) weights. Perhaps starting with FJR #1 with a rider/gear load of 160lbs and increase by an increment of 20lbs until max load capacity of the FJR is reached.

 

[cruppelt]

Like always great work, Pickles!

Personal efforts like this are what make this board so enjoyable. I always thought that the C14s advantage wouldn't be quite as much as everyone made it out to be based purely on the engine spec. Great to see that they are not as far apart. What difference does a tuned PCIII add to the equasion, does it take the catch up speed past the 100 mph?

Well done!

 

[UselessPickles]

Would be interesting to see the drag race between multiple FJR's at different rider (or load) weights. Perhaps starting with FJR #1 with a rider/gear load of 160lbs and increase by an increment of 20lbs until max load capacity of the FJR is reached.

There's lot's of interesting comparisons that could be made between the same bike and itself with various tweaks: different rider weight, difference between full and empty gas tank, launch at different RPMs, different amounts of time to shift gears, shift at redline in all gears compared to optimal shift points. On bikes with a chain drive, I can also experiment with different sprocket sizes.

Generating/graphing data for rider weights in increments of 20lbs would take a while, and the graph would probably be way too crowded. Looks like the average American male is ~190lbs. I'll weigh my riding gear tonight to come up with a number to represent total weight of an average male rider in full gear. Then I'll compare that with -20lbs (like a half tank of gas) and -40lbs (like an empty tank of gas). This should give a general idea of how much of an effect weight loss has on the FJR's performance.

Is there any other comparison that would be extremely enlightening?

What difference does a tuned PCIII add to the equasion, does it take the catch up speed past the 100 mph?

I would need a torque chart from such a bike to answer that question. Conventional wisdom on this forum seems to indicate that a PCIII alone does not significantly improve full-throttle torque on the FJR, but instead smooths out the partial throttle areas. I have not seen a before/after dyno chart for a stock bike adding a PCIII, so I don't know how true that is.