2008 Dyno Pull

[carlson_mn]

Saw many other bikes doing pulls and all seemed pretty spot on with what I have seen in magazines. My numbers seem typical but I may be sporting a few extra ponies than the average that I have seen.

The third pull is the one that is down a couple hp, probably a little heat soak. I always enjoy looking at these so thought I would share. Pulls were done in 4th gear, no connection to the spark plug so it is mph based rather than rpm. Tuner said the AF is spot on and he wouldn't change a thing if he could.

My bike: 2008, 36k miles with stock header, Leo Vince pipes with baffles in, stock airbox with funnel cut about 2/3 off (don't like flipping the air filter) and all CO's set at +7 over stock (17). Air filter has about 13,000 miles on it and I haven't touched it.

For reference I think 90mph in 4th gear is about 5500rpms which is when the FJR starts making 100+hp. I think that's pretty cool. Pretty impressive plateau of peak power on top as well I thought.

]

 

[LAF]

Thank you for posting. Interesting stuff for sure. These things sure do got the HP to "get er done" for sure. DO you know what max TQ numbers were?

 

[GeorgiaRoller]

stock airbox with funnel cut about 2/3 off (don't like flipping the air filter) and all CO's set at +7 over stock (17).

Can you explain more about both of these settings? (Airbox mod & CO settings?)

Wilbers 640 shock? I googled that and all I see are ones that fit BMW bikes? Does yours have the preload adjustment knob as well? How much did yours cost? How effective is it over the OEM shock?

127hp at the rear wheel is about what I've seen stated in magazines for the FJR. I remember one stating 145hp at the crank & 128hp at the rear wheel. Your Dyno seems to be right about there.

 

[carlson_mn]

Thank you for posting. Interesting stuff for sure. These things sure do got the HP to "get er done" for sure. DO you know what max TQ numbers were?

No, I think they have to tap into the ignition to get an accurate tq/hp overlay. Or sumtin like that.

stock airbox with funnel cut about 2/3 off (don't like flipping the air filter) and all CO's set at +7 over stock (17).

Can you explain more about both of these settings? (Airbox mod & CO settings?)

Wilbers 640 shock? I googled that and all I see are ones that fit BMW bikes? Does yours have the preload adjustment knob as well? How much did yours cost? How effective is it over the OEM shock?

127hp at the rear wheel is about what I've seen stated in magazines for the FJR. I remember one stating 145hp at the crank & 128hp at the rear wheel. Your Dyno seems to be right about there.

The wilbers I got used with 10k miles on it for $500. It is height adjustable and has the remote proload adjustment knob. It is better than stock, does not get the rear end wag at higher speeds, it doesn't bottom out in the apex as much as stock, and mostly I just liked raising the rear end up so I don't grind pegs as easily and it looks better. Having said that I think the stock shock was pretty capable and was never one to rag on it.

That funnel in the airbox I cut off about 2/3rds of it. I just did it so the air filter would get more even air. CO I just went with what others had said seemed to smooth their bike out, and I didn't do it until after I put the pipes on. It ran perfect at the stock level of 10 as well but does seem a bit smoother at 17.

 

[SkooterG]

Thank you for posting. Interesting stuff for sure. These things sure do got the HP to "get er done" for sure. DO you know what max TQ numbers were?

No, I think they have to tap into the ignition to get an accurate tq/hp overlay. Or sumtin like that.

Horsepower and torque are just mathematical functions of each other. Once you know one, it is easy to get the other. I am surprised they didn't put the torque curve on there.

More specifically, a dyno actually measures torque and rpm. The mathematical formula HP = Torque X RPM/5252 is then used to calculate Horsepower.

 

[SkooterG]

Wilbers 640 shock? I googled that and all I see are ones that fit BMW bikes? Does yours have the preload adjustment knob as well? How much did yours cost? How effective is it over the OEM shock?

Waaay back in January of 2005 Warchild conducted a group buy on Wilbers shocks. Hence many of us have them from the OLD days. I've got about 250,000 miles on mine.

Some old history: Clicky 1. and Clicky 2.

 

[carlson_mn]

Something about he needs an exact tach signal in order for accurate tq to be displayed on the graph. Torque is a measure of FORCE applied, with no care for the time over which that force is applied. HP is force applied over a certain time. Because this dyno measures both the force applied and the time, it can accurately measure HP. I don't see how the two can be separated but I can see how torque can only be accurate on this type of dyno if an accurate tach signal is displayed; the dyno has no idea if it's an FJR or a GSXR-750 that is doing the "work".

 

[SkooterG]

Something about he needs an exact tach signal in order for accurate tq to be displayed on the graph. Torque is a measure of FORCE applied, with no care for the time over which that force is applied. HP is force applied over a certain time. Because this dyno measures both the force applied and the time, it can accurately measure HP. I don't see how the two can be separated but I can see how torque can only be accurate on this type of dyno if an accurate tach signal is displayed; the dyno has no idea if it's an FJR or a GSXR-750 that is doing the "work".

I'm not getting it. 'Horsepower' is not measured, it's calculated. You say the dyno measures force applied. Well, that IS torque. The 'time' for HP is rpm. If torque measurement is not accurate, than neither is horsepower calculation.

 

[FJR Bill]

Thanks for the post. Before I looked at the chart I predicted it would show 128 RWHP...I wasn't too far off. Your results seem very consistent with other dyno results I've read about. Seems there is typically about a 15% HP drop from the crank to the rear wheel. I know this isn't a perfect formulae but I think it's a close estimate. When you think about it for a touring machine that's pretty impressive numbers. I'm satisfied with my 09's performance. Crossing the country last May it was dream passing trucks/cars in tight spaces between turns.

Bill

 

[carlson_mn]

I'm not getting it.

Horsepower is the rate at which work is done, which the dyno can measure. I'm not smart enough to help you get it beyond that. Go talk to a dyno engineer.

 

[SkooterG]

Horsepower is the rate at which work is done, which the dyno can measure.

Yes, but Work is calculated by measureing Torque. So the dyno actually measures Torque.

I'm not smart enough to help you get it beyond that.

Perhaps because it's impossible to explain what you are trying to?

 

[carlson_mn]

hey nerd, if ya know it all you explain it to me. Just tellin ya what the dyno guy said. Since you're the smart one, tell me how they should have accurate torque on there without knowing what rpm my engine was working to create that force on the drum (through differeing gear ratios, wheel diameters, etc). Then go tell the factory trained dynojet guy who did it how to do his job because I would love to see the tq values on there, it'd save me the five minutes to calculate it myself.

Like I said, there's my dyno chart for your enjoyment.

 

[SkooterG]

Like I said, there's my dyno chart for your enjoyment.

But I am NOT enjoying it without a torque curve!!!

 

[Redfish Hunter]

Thank you for posting. Interesting stuff for sure. These things sure do got the HP to "get er done" for sure. DO you know what max TQ numbers were?

No, I think they have to tap into the ignition to get an accurate tq/hp overlay. Or sumtin like that.

Horsepower and torque are just mathematical functions of each other. Once you know one, it is easy to get the other. I am surprised they didn't put the torque curve on there.

More specifically, a dyno actually measures torque and rpm. The mathematical formula HP = Torque X RPM/5252 is then used to calculate Horsepower.

I always thought that what Skooter is saying is correct. I have never seen a dyno chart that did not have the RPMs on it. That formula, HP=Torque X RPM/5252 is the known standard. The torque and horsepower will be exactly the same at 5252 RPMs. The lines on the graph intersect. Obviously, I don't know how to operate the dyno and I don't pretend to know more than the Dynojet Tech. I have just not seen it done this way before.

It does not matter to me, I really appreciate you sharing this with us. I wondered how much difference some of these mods actually made. Of course comparing the readings from two different dynos is almost useless, no two will read exactly the same. Again, I thank you for sharing.

 

[UselessPickles]

The problem with the torque vs horsepower confusion here is that the dyno measures the torque applied to the dyno's drum. It knows the torque applied to the drum, and the speed at which the drum is turning, and the diameter of the drum. So it can calculate horsepower and simulated road speed, and produce a graph of horsepower vs speed.

To know torque produced by the rear wheel, the dyno would simply need to know the diameter of the rear wheel.

However, what you are interested in seeing is not actually the torque produced at the rear wheel. The typical "torque at the wheel" curve is actually "torque of the engine, as measured from the wheel to account for drivetrain losses". A true "rear wheel torque" curve would be different for each gear.

The only way the dyno can produce a "torque as measured from the wheel" curve is to know the engine speed. Therefore, if you don't hook the dyno up to a spark signal (and configure it properly to account for the wasted spark design of the FJR), then there's no way generate the desired torque curve.

Another option would be to calculate the total reduction ratio from the engine to the drum (including the rear wheel to drum reduction ratio) in a particular gear and somehow configure the dyno to use that ratio to calculate the engine speed from the drum speed. Even if that option is available, I can't imagine a typical dyno operator volunteering to go through the hassle when most people are probably happy enough just knowing what their peak horsepower is.

 

[LAF]

Thank you for posting. Interesting stuff for sure. These things sure do got the HP to "get er done" for sure. DO you know what max TQ numbers were?

No, I think they have to tap into the ignition to get an accurate tq/hp overlay. Or sumtin like that.

Horsepower and torque are just mathematical functions of each other. Once you know one, it is easy to get the other. I am surprised they didn't put the torque curve on there.

More specifically, a dyno actually measures torque and rpm. The mathematical formula HP = Torque X RPM/5252 is then used to calculate Horsepower.

Understood. I was looking for the torque curve from the pull. Would be interesting to see what TQ is, and what and where on the curve that looks like.

I have been on a few Dynos in my life and while peak HP is cool to know, that plot, along with a TQ curve can provide a bit of insight into a particular bikes pattern.

 

[Bounce]

Something about he needs an exact tach signal in order for accurate tq to be displayed on the graph.

Odd that he had problems with Tq. My dyno tune included it as did all the references I found when documenting my results at:

https://www.fjr-tips.org/maint/dyno/dyno.html

(131.24 hp, 91.36 lb/ft Tq)

It's nothing more than picking the right options on the tuning computer software.

Grabbing the RPM is as simple as clamping the induction probe around the coil wire and telling the Dyno software the model of bike from its database. Alternately (as was mentioned) the tuner takes a tape measure and measures the diameter of the rear wheel and enters it.

Dynos MEASURE torque... they calculate HP. Your tuner simply failed to give you the additional reports.

Oh yeah... and more dyno time on my other vehicle here:

https://www.cobbtuning.com/Dyno-Database-s/70119.htm

Where you can pull up HP, Tq, Time, Speed, etc. simply based on the options you pick in the software that then runs the report against the collected data.

Sport v Sport# modes after Stage 2 and Dyno tune on "The Heart Breaker" (always reads lower than Dynocom) dyno by Mustang.

Note that all HP/Tq charts cross at 5250 because it's the constant used in calculating HP from the measured Tq.

 

[ahchiu]

I had my bike on the Dyno and he said they would need to get to the ECU to get a Tq reading on the graph. I got a AFR,HP and MPH readout, this was a free dyno day at a shop and lots of people so no time to tear into the bike.

 

[carlson_mn]

I had my bike on the Dyno and he said they would need to get to the ECU to get a Tq reading on the graph. I got a AFR,HP and MPH readout, this was a free dyno day at a shop and lots of people so no time to tear into the bike.

Yeah exactly what I was told, and it was a dyno event so it was about 10 minutes in and out per bike. Torque display will not be accurate without a good rpm hookup.