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Discussion Starter #1 (Edited)
Has anyone used this with their CBR250R yet? I have been reading a number of favourable reviews of the Dynolicious app ($12.99) which is a performance meter for the iphone and ipod touch that utilizes the accelerometers native to these devices. Below is a link to a YouTube video that provides some details about Dynolicious.


You have to configure Dynolicious before the first run by inputting a few pieces of data related to the bike and the figures you wish to obtain (e.g., total weight of the bike and rider; decide whether a roll-out will be used; decide whether you wish to have an estimate of crank or wheel hp, etc).

I decided to try this device on my CBR150R, as I just received a fuel-programmer for it and wanted to obtain some stock performance figures. I know of an isolated paved (and flat) roadway in the middle of the nowhere - that is virtually empty of traffic and void of any homes. I ran a few runs there to test out the device. One issue that I ran into immediately was that the results kept indicating the CBR150R was reaching 10 mph in about 10 secs. I knew this didn't make sense. The unit may be starting because the vibrations from the bike are setting off the G meter. I will have to take a look at that.

I ran the bike through the gears and recorded a few runs. Unfortunately, after each run the app detected an error (this may have been due to slight movements of the ipod touch inside the clear plastic sleeve of my tankbag). However, the runs still remained relatively consistent. I have since purchased a skin with an armband for the device and hope to try tethering it directly to the top of the fuel tank (perhaps with some foam underneath for support and to reduce vibration).

If I can't find a way to get Dynolicious to record consistent times that are free of error warnings, I may spring for a GPS performance meter. The best (and most affordable) one I've found is the Performance Box.

http://www.performancebox.co.uk/

I saved the run below, as it appeared to be representative of the kinds of results I was obtaining. With that said - there were still errors in the pass so the results are really only tentative until I can find a way to produce a clean run. One pass yielded an 8.0 second 0-60 mph time, but it recorded my top speed as 90 mph (which I knew was false) so I just discarded the results.



CBR150R: Outside Temp: 10C Wind: small tailwind

Modifications: Full Giannelli performance exhaust, K&N Air Filter, intake snorkel mod, 14T sprocket.

0-10 mph.....1.58 sec
0-20 mph.....2.54 sec
0-30 mph.....3.69 sec
0-40 mph.....4.95 sec
0-50 mph.....6.60 sec
0-60 mph.....8.41 sec
0-70 mph.....11.05 sec
0-80 mph.....15.51 sec

1/4 mile 17.10 sec @ 84 mph
Peak HP 22 HP

I set up Dynolicious to assume no drivetrain losses - which helps to explain the slightly high hp figure. There seems to be some slight deviations in the hp figures after each run anyway, so that should be factored in.

Mike
 

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The accelerometers in cell phones aren't really sensitive enough for these kinds of measurements to make sense. They're mostly there for telling the phone's software which direction the phone is being held by sensing the earth's gravity. The app probably does a *ton* of fudging in software to get semi-realistic numbers, which is probably why you didn't see much consistency in your results. I have no idea how it got numbers for MPH unless it was also using the phone's GPS.
 

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Very cool app considering you didn't really have to buy any new hardware. Cobra actually has a piggyback fuel controller that continuously auto tunes and learns for the best acceleration at any given throttle angle/ load based on accelerometers.
Checked out the Cobra USA web site hoping they made a fuel controller for our bike, couldn't find, seems they only make for cruisers.
I'm hoping I missed something.
 

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I read an article recently that spoke about those apps. They aren't very accurate. I'll try to dig up the reference and post it.
 

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The accelerometers in cell phones aren't really sensitive enough for these kinds of measurements to make sense. They're mostly there for telling the phone's software which direction the phone is being held by sensing the earth's gravity. The app probably does a *ton* of fudging in software to get semi-realistic numbers, which is probably why you didn't see much consistency in your results. I have no idea how it got numbers for MPH unless it was also using the phone's GPS.
False, the iPhone accelerometer is extremely accurate. If not too accurate for some of the games that make use of it. Even the smallest movement effects it and makes it hard to hold where you want it.

The consistency would be due to how it's driven. If you are a pro and do a perfect launch every time then it's consistent. But it is only as consistent as the rider. Though I can see the vibrations of the CBR triggering it, you can adjust this in the settings.

I've seen this thing compared to real dyno results and showing that it was just as accurate as 1 dyno brand vs another is.

The HP figure is probably a little off but this is all based on weight of the bike and rider combined, only accurate if you weigh it.

I have not done a run on mine, I should have done it a few times.. lol I have the perfect mount for it

 

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Does the position of the phone make any difference to the accuracy of the accelerometer?

Seems like it should be mounted perfectly horizontal to give the most accurate measurements, or doesn't it matter...
 

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Discussion Starter #9 (Edited)
The consistency would be due to how it's driven. If you are a pro and do a perfect launch every time then it's consistent. But it is only as consistent as the rider. Though I can see the vibrations of the CBR triggering it, you can adjust this in the settings.
Yes - that is very true. My launches weren't of the "high rpm clutch drop" variety. I simply tried to launch much like you would if you were at a light and wanted to take off briskly to get well ahead of traffic. Using this technique, it is challenging to launch with completely consistency - the same way - all the time. Also, because the device was starting (tripping) the timer as soon as I pressed "GO" on the ipod, I had little time to take my finger off the device and then grab the throttle and.....go. If I set the "G-force" settings a little higher - the device should then trip the timer when the bike begins to accelerate - not when when it is still stationary.

Having said that - the runs were still reasonably consistent considering all the factors involved that can introduce variability to each run. All my runs from 0-60 mph varied between 8.0 to 8.6 seconds. This included some runs where I bogged on my launch. This could easily account for half a second. If I had time to get my throttle hand ready to rev the bike a bit - to get into position - and to mentally prepare - I bet the consistency would improve substantially.

And the horsepower figure might be off a bit. The bike is supposed to make 19.5 hp at the crank. And the unit appears to round off hp figures, so the actually figure could have been 21.5 hp. Then again, I have a few mods (full performance exhaust, modified intake snorkel, K&N filter) and it wouldn't be unreasonable to expect a 1 or 2-hp bump from these modifications. The overall weight could be a bit off too. I am considering riding down to our local recycling/landfill depot and having me and the bike weighed on their scale.

Mike
 

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Discussion Starter #12 (Edited)
Can you edit the charts graphically after you get home? You could chop out the start. When I did my timed runs, I decided to do a rolling start at 15mph to eliminate the variable of the launch and also to save the clutch.
Sendler - I don't recall the charts as being editable. Then again - I haven't really delved too deep into the software either. You can select a drag strip like roll-out of varying distance (1 to 24 inches) as well and this might help eliminate inconsistencies in launch technique.

Except for variations in the 0-10 mph figure (due to botched launches) I found remarkable consistency across the accelerations times - the time to reach each speed (e.g., 10mph-20mph-30mph-40mph-50mph-60 mph) was consistent across each run.

Mike
 
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