Anybody used this app before? "MicroDyno" ... or 'SIP HorsePower Dyno' What kind of results do you get? Post them here. Here's mine, I'd guess its not so far out at all. Pretty amazing really considering you just record the engine on your phone!!!
EDIT*EDIT*EDIT*EDIT*EDIT*EDIT*EDIT*EDIT*
**EDIT** - The final conclusion (it works) and helpful tips on how to get consistantly reliable results, are near the bottom of Page 4** (The following few pages are experiments, trials, guesses and estimates).
The graphs below show minimum revs to maximum revs where i held it for a couple of seconds - IN 3RD GEAR!
The revs on the first 'spectrum' graph dont seem to tally with my SIP speedo tho' but the results seem to be pretty accurate...or at least in the ball park! I tried quite a few times and always got the same readings so at least its consistent!!
I recorded this (on my phone) when my scooter was set up and going very nicely without wanting to change anything (in *Edit - 2012)....its all for fun....but pretty informative!! I will be comparing my results to my recently rebuilt (same) engine, hoping to achieve around the same results.
(the revs are on the left, although my speedo showed maxed out at 7300rpm, which is probably limited by the SIP road);
and heres the final graph:
i realise its not going to break any records but that wasnt my aim!
If you'd like to compare, my set up was:
Pinasco 224 24/24e carb SIP Road (mkl) 130 Main Jet 50/120 Idle Ignition 19' Tyre circumference 1320mm Primary ratio = 65/23 = 2.83 Overall ratio (in 3rd gear) = 38/17 x 2.83 = 6.326 Weight - 220kg Cw value - 0.5 Front area - 0.75m2 Air pressure - 1010 millibar Temp - 20'c
My 'test track' was slightly uphill (barely) and i tried up and down the same stretch of road lots of times, with very similar results, sometimes 17PS) sometimes 16.5PS so I used this one as a happy medium!
In case you cant see them, the results were; 16.83PS @ 6775 rpm 17.7Nm @ 6489 rpm
Sticky had some very complimentary things to say about this app in Scootering about a year back IIRC
SBW Nik - cynical about scooters since 1982, but still refusing to give them up as he hopes one day one of them will prove him wrong.
P200 Day-to-day and Rally bike 'One Careful Owner'
Cosa 200
About to start work on building that rarest of beasts, a Cosa chop. It's taken long enough to get this far, the P207 chop will have to wait a bit longer...
Assorted projects I REALLY need to crack on with
Including my wifes T5 Classic, hurry up and paint it!
[b
Im not sure who sticky is (i havent bought scootering for years now) but im really impressed by how accurate it seems to be and how consistent it is. The only thing is, i think the app is only available on Android but ive just had a look and its still only €0.99!! Bargain!!!
I used the free one a while back, but didn't get anything useful from it, so gave up and uninstalled it. The full version, normally £6.24, is on 'Christmas Sale' for .99c, so I will probably give it a go; I do like a bit of gadgetry if it works. I was reading the tutorial on it earlier, which I think will give better results (following English Instructions). Will link to tutorial in the morning if no one else does; I'm not on my computer at the moment - running some memory tests on it overnight.
The video tutorial is part of a web page with lots of other stuff, including a written tutorial; for anyone who'd like to make their own minds up if it's a waste of time or not, it's here:
i dont believe it is guess work or a waste of time. if you do it wrong its probably a waste of time. it does work. its a little complicated at first but easy enough. I have no real need to know my PS or Nm, as i said, its more for fun and for something to compare against at a later date.... which will be very soon,,, (as soon as i can physically ride my scooter again - (ive been through the wars lately) and literally aching to ride it again)). the figures i compared to were of similar set ups on a dyno and using this app. all were in the same ball park that was expected. I will be comparing my own readings to my own readings if you see what i mean. the graph above is my benchmark/datum point of a nicely working smooth motor. I'll be changing my base gasket at some point (just because i can) and will use this app (aswell as the usual methods) to note the differences. do remember these results are 'real' on the road readings, not in a workshop on a dyno, so may likely be a little lower than some real dyno readings. Like i said, its consistently accurate enough for what i hoped to acheive. if youve ever wondered what your power curve is like, or how many horses you have, then you have nothing to loose as its free, (or 0.99c)
If youve had your motor on a real dyno then try this app and compare for yourself. If you follow the instructions i believe you will surprised.
I did find it a little difficult to get a 10 second recording as in 3rd gear my motor reached WOT after about 6 seconds! but even with starting at lower revs or holding it at WOT for longer i get, pretty much, the same results.
i found this also helped to gain the correct gear ratios to enter into the equations.... SIP gearbox technology pdf.....
I'm rushing out, so will read yours properly later, vespasco. I agree it isn't a waste of time, but I wasn't going to get into a debate on that last night - which would have been a waste of my time! I'll be giving the proper version a proper go, properly; not skirting round the complicated bits. - Hence my links to the tutorial for others to make their own minds up. It's as good as the data input and the testing method; you nailed it: 'If you do it wrong its probably a waste of time.'
Hope you made allowance for your leg sticking out when inputting your figures!
Biscuits? - Only as good as your last performance; biscuits is a done deal, I'm moving on. Think blowing stuff up will be involved.
Sticky is a long time contributor to Scootering, I'm pretty sure he has a PhD or similar in Engineering, he knows his stuff
SBW Nik - cynical about scooters since 1982, but still refusing to give them up as he hopes one day one of them will prove him wrong.
P200 Day-to-day and Rally bike 'One Careful Owner'
Cosa 200
About to start work on building that rarest of beasts, a Cosa chop. It's taken long enough to get this far, the P207 chop will have to wait a bit longer...
Assorted projects I REALLY need to crack on with
Including my wifes T5 Classic, hurry up and paint it!
[b
can see how it would work an give indications of improvements/degrades,so long as you exactly reproduce the run each time , an follow the "destructions" to the letter ,but would like to see back to back comparisons to a "conservative" dyno really ,then you might be able to calibrate the app to get approximations of real world BHP at the rear wheel, otherwise theres too many variables for it to be accurate on every scooter/set-up/weather conditions , i guess,puters/apps not really my thing , for jetting runs i can see how it would narrow down the throttle range/revs to fettle to get right , i wonder if theres a app to give real time tacho/rev counter from your phone mic, probably ,H
if its got wheels n makes a noise I wanna play with it, skateboards included coz "skate-punks rule",
The developer has compared it to the GSF dyno (links below) and to the P4 dyno they use in germany and he was always within 0.5HP. So the app is already 'calibrated' , giving HP at rear wheel (not at crank) As you can see, you can record the rpms, just not on a display in real time though. Try a rev counter for that! My understanding is it basically works by using the differing sound frequencies you get from the differing rpm.
Inputting the same variables, using the same test track, riding in the same position, with the same weather conditions on the same day etc is easy enough, not really much different from the variables you can input on a dyno. You can get accurate weather conditions directly from within the app (or punch them in yourself). Most other 'dyno' apps use the GPS and accelerometer functions on the phone which is nowhere near as accurate. Unless they use an expensive interface such as you would use on modern cars (and bikes i guess)
I recently came across the WAV file of my scoot (from when i first used this app a couple of years ago) so re installed the app and punched in the figures to obtain the tesults as shown above and hence the post. Id kind of forgotten about this app until now. And now its going to be quite useful after my rebuild and my future tweaking im going to have to do. Ill be experimenting with timing and jets mainly but if i have time/can be bothered i will try a couple of different exhausts too, aswell as altering the base gasket. Time will tell..i still cant walk properly as yet. I truely believe the app will be a big help..... Tip: for more accurate readings, use 3rd gear!!
An Acoustic Tacho here: play.google.com/store/apps/details?id=com.javiery.rpmgauge I always try to use the free ones first, just downloaded it - not tested, but it does work for single cylinder 2stroke. There's quite a few available. These apps are always a bit of trial and error, and it's easy to rubbish them rather than persevere.
It's easy for good threads to be led off the subject too.
Getting back to the subject, I have tried to download the full version, but can't get price to come up as 0.99c rather than £6.24, so still working on it. Latest... Just had an email from Stefan (developer) that it should not still be listed as 0.99c, so looks like that was last Christmas! My phone doesn't like the download size of the free version, which is twice the size of the full version, so waiting for another email to see if I can get it for list price. (I do not need advice on downloading, where to get it, freeing up space etc., etc., etc, - thanks)
All your lovely facts, figures and links will be thoroughly explored later. Some of the stuff I've learnt here since trying it before will help too, cheers.
i downloaded the acoustic tacho...made me laugh..reading/flittering anywhere between 2000 - 8000rpm with the phone on my desk in a quiet room!! (it does mention its not so good for air cooled 2 strokes)
Cheers vespasco, I did have a play with MicroDyno yesterday, and gone as far as I can until I get on the road, probably on Sunday. Was going to update if/when I had something constructive to offer.
But got it installed (the free one for now – [“This is the Free Version, no values are displayed at the result screen and results cannot be saved”.] – chappy went quiet on me when I asked for a redeem code for 0.99c as listing; not sure if free one will do anything useful), playing with settings anyway – all subject to checking/tweaking, but used the tutorial and gear calcs to get as accurate as I can:
· Weight is Dry weight + me + fuel/oil + battery + toolbox + bolt on bits (consistency important for comparison, rather than precision) · Cw value – there’s a discrepancy between advice in tutorial and advice in app, but consistency is more important. App reckons this value doesn’t need to be exact for app to work, so I’ll just leave it alone until/unless I learn better. · Front area – I’ve increased it a bit for me + winter riding gear, not bothered about flyscreen because I’m behind it, but I’m quite a big chap anyway. · Air pressure is current local, but my bike computer gives good readings, so will use that on day. · Ditto temperature; correct for day.
So, I’ll check/tweak/have a think about those settings and give it a go on the weekend; see if we get anything interesting……………. (I'll decide on weekend, after a play, whether or not to go ahead with full version.)
TO YOUR POST:
I downloaded your Wav, and played it with the acoustic rev counter sitting by my speaker – and made a film of both together – BECAUSE I CAN – It does appear to be a tad jumpy; it’s only the first free one I came across, not tested it on scoot, there’s settings to play with, and other apps if this one is a dud, but have to agree first impressions are disappointing.
No idea what purpose this serves; just getting used to the app really. Just out of interest, but of no other value, I did play your wav back into my MicroDyno and have a play with recording and trimming; and got something similar to your graph. You have to bear in mind that this is your recorded wav., played over my little computer speakers, into my ‘phone microphone, and then recorded and trimmed by my inexperienced hands – so loads of opportunities for inaccuracy/distortion. (Seems like the recording/playback has increased frequency or something on microDyno and AudioRPM). I also noticed the last third of the AudioRPM movie did show a fairly steady rise from about 6900 – 8600 rpm, which I think is high, but sort of ties up with the graph I got in MicroDyno. I agree that the rev counter app was not good, but if you watch the movie of it, the last third is mainly a steady rise in revs. Neither the graph nor the movie mean anything; just playing. Anyway, I’m just playing, experimenting, observing; if I get something similar to play with for my scooter on the weekend, I’ll be inclined to buy the app and persevere to see what sort of results I can really get. Hopefully get something meaningful as a benchmark before playing with engine in spring. Itching to have a go on the weekend now……….
This is your wav, played back into the app on my phone – just out of interest:
hopefully stefan will want to sell a few more and bring the price down...but i do know he spent a lot of hours and effort getting it right and was hoping to bring it out on the iphone too. luckily for me i bought it when it first came out for .99c! so still have it until about 2035, when we'll all be riding 'hover scooters' and wearing silver space suits and plugging our even rarer vespas direct into out brains to tune them.
i figured my o/a weight was; 103kg - rally 200 10kg - fuel and oil 20kg - tools/toolbox 80kg - rider (at the time anyway ..i may have to add a few more kgs to that total when i re-test)! 7kg - misc 220kg - total
Cw values - my app came with 0.5 as default but I will alter that to 0.8 after seeing yours and also this.... 3D modelling of a vespa: www.vespalabs.org/Projects/Vespa_CFD%2F%2F3D_Model ah sorry... thats not right link and now i've 'lost' it! but 0.8 sounds very very close from what ive just looked at. This Cw value does have a small effect on the results so this should be as accurate as possible.
...which also made me check my default value of 0.5 for front area of scooter and rider and found this: Aerodynamics of a vespa: www.vespalabs.org/Wiki/Vespa_101/Dynamics/Aerodynamics which comes up with a figure of 0.81518 m^2
Air pressure you can check and change on the day (from within the app if you want) but its getting colder...so 1000millibar and 10'c seem more realistic, although this has minimal effect on the results.
i did also notice the other 'acoustic' app seemed to smooth out towards the end yes..ill give it a go when im back on the road. maybe download another even although i have a rev counter on my scoot.
As for using my WAV file ... yeh its just for fun and im sure you know but it would be much better if you downloaded my WAV file direct to your phone digitally and use it 'direct' rather than analogue.
All this has made me play with some figures..... (plus i have the luxury of using a pc, mouse and a proper keyboard and fast broadband....sooooo much easier and i dont spend half my time editing spaces inbetween my words!!) Using the results from the MicroDyno app and maths heres how they compare...and i think its pretty damn good....
In 3rd Gear;
km/h = (rpm x tyre circumference in mm) / (Overall gear ratio x 16667) (6775 x 1320) / (6.326 x 16667) 8943000 / 105435.442 = 84.82km/h = 52.7mph @ 6775rpm sounds about right..i never really noted my speed at 6775rpm in 3rd gear but giving that it just about revs out @ 7300rpm to 60mph it aint far out.
Working backwards: (im just making use of the PC)! rpm = km/h x overall gear ratio x 16667 / tyre circumference mm 8943034.2 / 1320mm = 6775 rpm
This is just maths really but in 4th gear: (7300 x 1320) / (4.7 x 16667) = 9636000 / 78334.9 = @ 7300rpm = 123.01km/h = 76mph
Below is, just for fun, using my WAV file with your stats sime: What i did notice however that you worked out your o/a gear ratio using 4th gear.... to be more accurate its actually recommended to use 3rd gear. So a stock PX150EFL would be: Overall gear ratio (in 3rd gear) = primary x secondary (68/21) x (38/17) = 3.238 x 2.235 = 7.237
and using, just for fun, the following values: Tyre circumference - 1320mm Overall Gear Ratio - 7.237 - 3rd Gear!! primary gear ratio - 3.238 Weight - 250kg Cw-value - 0.8 Front area - 0.81518m2 Air pressure - 1000 (its getting colder)! Temp - 10'c
So, using my WAV file and your stats in the app, (remember its a different scooter)!! so again, please dont phone.....its just for fun, you would get the same power curve and the same peak power @ the same revs, although the final results of HP and and Nm would be slightly different (due to different gear ratios)....
So, for example, using my WAv file and your stats , in 4th gear @ 7300rpm (7300 x 1320) / (5.4 x 16667) 9636000 / 90001.8 = 107.06km/h = 66.52mph
Note: i got 5.4 as o/a gear ratio...? or have you got different gearing somewhere? or more accurate values? not much in tho'.
Ah yeh... that last one looks better... i meant to add i think you had the wrong rev range on the first frequency spectrum!! although mine does auto snap to the correct one, which you can set in the menu.
Up early, hoping to deal with a meaty post from you, and you haven’t let us down; lets see how much we can get through before coffee gets cold and day’s distractions take over – it will probably need more thinking and adding to later…….. I knew there was a decent thread in here.
(Boring bit first – app advertised at .99c on Play, app front page even says €2.99, but wherever I look the full version is £6.24 - €7.99, which is a lot for an app, but only a tank of petrol; I’ll decide after the weekend. It does mean for now that all the calcs are unusable, and I just get the first graph – unless I send my wav to a man-who-can )
I realised I should copy your .wav file into my SIP directory, but wanted to stop last night, or I’d have been at it all night; I’ll do that this morning, but once I’d realised I was looking at the wrong band, and corrected it, my statement about the distortion became irrelevant.
I won’t be riding a hover-scooter; my scooter is going to outlast me!
To the figures: (I’m going to spend more time on this later, most figures only become relevant in the full app, but I can make .wavs anyway) · I haven’t been 80k/12.5Stone since I was a teenager! If you’ve been watching any Autumn International rugby lately, I’m a prop, not a winger! I was a prop at school actually – always been a big lad. (Heavier than usual at present (too much scooter, not enough bicycle) - 115kg/18.5Stone; 100kg at absolute best these days). I know my toolbox contents weighs 8kg ‘cos I weighed it before when I was trying to cut it down a bit. I reckon my 250kg is too many items rounded up before adding together and rounding up again; I’ll get closer over the weekend. If you’re 80kg then your MicroDyno weight will be 40kg less than mine, I also have a battery. · I know I’m out by 0.01 in my gear calc, didn’t change my screenshot, so I’ll redo it long-hand here to check it: (1983 PX150EFL) Primary 68/21 = 3.238095, 3rd 38/17 = 2.235294, Tyre 1355mm (measured), Overall gear ratio with tyre: ((68/21)x(38/17))/1.355) = 5.342 · CW area – I’ll have a read-up later, certainly before the weekend. Using 0.8 · Front Area – I’ll have a read-up later, certainly before the weekend. Using 0.8 · Temp pressure – Set on the day
I’m a bit muddled with your calc for my gear ratio, but don’t want to get caught up in that for this morning’s post (I can’t agree your figure, I think I’m right, I don’t want to fight, but we do need to agree it later on if one of us is inputting incorrectly). Other than that I reckon we’ve got the input data covered for now, but always open to any new information to get those right; will explore Net later today for Cw and front area. It’s more important to the end figures, and is adjustable afterwards from what I’ve seen of the app so far anyway. See below, if this helps follow my calc; maybe we have different input screens if you’re using an older version of the app? I’m pretty sure I’m following the instructions that go with my version:
Moving on to gear ratios/revs/speed; I need more time than I’ve got right now to look at, understand and play with your numbers, but I do like the way this thread is developing. I haven’t got a rev counter (more of that at the end of this post), but when I do my test run(s) I will have a GPS top-speed for 3rd and the SIP data to play with, so I can develop my own calcs then. My top revs/speed will be considerably lower than yours, obviously.
When riding ‘spiritedly’, I change into 4th at about 80kph normally (on my speedo, which is out by about 10kph, so call it 70kph – which is 43mph, which ties up well with gear/speed calcs done before) I do not ride it WOT in third normally, so don’t know where it will go. In 4th it will slowly go off the clock, but I don’t tend to bother – it’s going to last me another 30 years, not 30 days! (Of the three things in your post to kidda, speed is actually the least important to me).
As far as some of the stuff I first posted when trying to make sense of the .wav and rpm data and apps we were playing with yesterday, I made some wrong assumptions/leaps of illogic that we’ve both realised were wrong. To summarise those: 1. We have to concede that the first rpm app is probably not up to the job; I’ll see if I can find a better one, but MicroDyno is my priority here for now. 2. Your .wav file was a lot more use to me once I had read the app instructions fully, but blokes do tend to like to have a go before reading the instructions, and I got carried away. – I will have a go doing it straight from your .wav file copied into the SIP directory; next job, but it’s all much more sensible when the right band is used anyway. 3. This is fun/interest/learning – I’m quite happy to bounce figures and ideas about; some of which will be wrong before we’ve thrashed it out, which is a good exercise in itself anyway.
I think that’s me for now. The subject and the app has caught my interest now, I have a bit of catching up to do, but I’m on it……..
Just had my last gulp of cold coffee, it’s got light whilst I’m writing; time to get on with the day. More later.
Edit: Already covered really, but couldn't resist a final tweak; your .wav file copied into SIP directory for MicroDyno, then max revs set before snapping - now it snaps to correct band:
wow guys ,that seems some fancy kit ya playing with , going by the amount of words/puter speak i didnt understand ,will follow thread with interest an look forward to ya conclusions ,ya never know might spur me on to go 21st century n get my head round apps ,H
if its got wheels n makes a noise I wanna play with it, skateboards included coz "skate-punks rule",
2001 Vespa PX 200 EFL (935 CPC) 1963 Lambretta Li 150 Jimmy Quadrophenia replica (251 KRU) 1963 Lambretta Li150 now 198cc (BOE198A) 1961 Royal Enfield 500cc Bullet 'Army' (222 UXB) 1978 Lomax 223 three wheeler like a Morgan (LXI 59) 1984 Yamaha RZV500R Grand Prix Race Replica V4 two stroke 1999 Suzuki TL 1000 R Special 2014 HBC Marlin III hovercraft! 2015 AJS Modena 150cc T & G
Morning all – or anyone who ain’t out ridin’ on this beautiful day!
Made some progress wth MicroDyno this morning; something to show, although limited with the free app for now, so not a lot of actual data here’s what I’ve got anyway:
Settings:
Dyno Graph:
Wav - Feel free to download it and do me some MicroDyno figures if you really want to, vespasco :
Side by side with your’s for comparison, Vespasco:
And, for me really, what she lacks in grunt, she makes up for by looking splendid in the morning, misty sunrise!
I’m away to do some other jobs, and ponder what I can do with this information. I know I have to redo them anyway because MicroDyno didn’t pick up my GPS speed for some reason, so didn't get a max to pin revs down. (on my speedo it was around 90kph, but swaying about a bit between 85-95). I really don't like thrashing it for long in 3rd - feels bad. Anyway, it’s a start………..
I know we’ve been chatting and swapping files this morning, but a couple of afterthoughs, without disturbing the job you’re on with:
· Is the small discrepancy in gear calcs just because of different tyre circumferences? – I’ll check that later……. · I’ve sussed out how to turn GPS on in the App; I was turnig my GPS speedo on, but not switching it on at the ‘Record’ page in the App. I hope you can get something with the files without that info, but I’ll try to do them again (tomorrow?) anyway. · It’s like waiting for test results at the doctors! – Whatever numbers you come up with, I can see I was in the high 6,000s, which I’m happy with considering the box of broken bits I had back in the summer. – And the potential for improvement in the Spring with the Transfer Port Timing tweak.
for truer accuracy its always best to measure your tyres actual circumference than rely on the standard measurements given in gearing calculators, as tyre wear an pressure can make a difference , but in use an at higher speeds/loads tyres grow ,by between 10-20mm ,depending on type an maker , its a discrepancy that most if not all apps/calculaters just ignore ,as its not really measurable or predictable , so if your getting minor discrepancy's in your figures this could be the origin , H
if its got wheels n makes a noise I wanna play with it, skateboards included coz "skate-punks rule",
We're both measuring our own tyres, H, not using standard sizes. I suspect we're getting different results because I'm using 1335 and vespasco is using 1320, and maybe used 1320 when redoing my gear calcs, in which I used 1355. I just need to redo some numbers to check my suspicion, but I got carried away with playing on the road, and with the app back here afterwards.
Stefan has acknowledged he needs to do an App update to take account of tyre changes during use, so not ignored; just work in progress with his app.
vespasco, I've sent all three un-trimmed Wavs to you, but might have sent to the wrong address (your second message came from a different address); just thought I'd mention it in case they didn't arrive on the device you're using now. I tried re-trimming to get a lower revs start point in 3rd, but think I might have to redo my runs tomorrow; can't get much lower than 4,000 in any of them. - Gently does it in 2nd, start low in 3rd!
Here are the three screenshots side-by-side; doesn't seem to be much point concentrating on any one because they're very similar - you might trim a little better with a bigger screen, but there's not much to play with:
Right... Sorry for late reply... Life gets in the way sometimes.... Ive been playing with the files but youre right sime.... Unfortunately they all start off @ too high revs (above 4100rpm) and i cant use any of them.... I can see the curve i need but it just starts off too high. Youre looking for the curve on the spectrum graph that finishes off at 'around' 7500rpm. (The ones you have marked/'auto snapped' to sime are the wrong curves so i cajt use those either).
Another thing is .... Its quite noisy, lots of interference, especially towards the end of one of the recordings, on sime.1 i think... Sounds like you have the phone on your toolbox/handlebars? and its vibrating... Not so good.
Tips for any other potential converts: When recording, place the phone out of any air stream/wind, preferably behind you,ideally in a backpack, you may get away with it in a windproof jacket pocket?? but its got to be out of the wind!
Also, when youre ready to record.... Start recording Pull away, Ride slowly in 1st and 2nd, dont trash it in 2nd!!!! THEN change into 3rd, so as to start off at the lowest possible revs you can - this MUST be lower than 4100rpm!!!! When you reach max revs , hold it there for about 2 or 3 seconds, that should be enough. Then you can either change into 4th or just pull up and stop your recording.
Youre aiming to try and record the entire rev range in 3rd gear, out of the wind.
As for tyre sizes.... I measured by marking tyre and ground, sitting on scooter, wheel it about 5 revolutions, measure the distance, divide by 5 (or however many revolutions you made).
Ive been in touch with the developer asking about 'overall gear ratios' and how they are worked out, as in the app its a little confusing.... Im waiting to hear back from him.
I also believe hes worked more on the full app rather than updating the free one, so this may also produce slight discrepancies.
Sorry sime but DR. Dyno will give you your results tomorrow!
That’s OK, you pre-warned me that those runs were starting with too high revs in 3rd, but I can improve my method tomorrow, based on the advice with that, get some wavs for the full-range, and turn the GPS on too. So there’ll better stuff to work with tomorrow. - Probably got a bit exited about trying to squeeze some revs out of it.
I’m a little unclear about snapping to a curve that maxes at about 7,500 rpm though, because: · I can’t see one on mine; I’d say they’re about max 5,000, 7,000 & 8,500 on my spectrum graph, but I’m very likely reading it wrong. The one I chose was the one I read to be about 7,000 max because I thought that’s where mine might be if it was doing well – the next one is 8,500ish, where my scoot don’t go. · I don’t think mine is able to get as high as that. Anyway, I think you’re saying I need the one above the one I snapped to, and that it needs me to start much lower revs in 3rd.
The phone was in my backpack, I can put it in its sleeve tomorrow to protect it a bit more; see if that improves things. It might also have been banging about against my camera; anyway, I’ll be more careful with that. Maybe I can think of a less exposed straight bit of road.
I’m going to read your post from the other day to try to find precisely where you didn’t agree with my gear ratio; I checked my figures and was happy that I got the same result a second time, rather than trying to follow yours through before, so maybe I’ll do that instead (work through yours to find where the numbers differ). The hunch might well have been one of my Red Herrings, but I'd wondered if you’d used your tyre size when doing calcs for my scooter and then compared your results with my calcs, which had used my actual tyre sizes – so different. I’ll try to have a better look at it, but tomorrow morning’s quiet time will be playing out on scoot again! (trying to produce a decent specimen for Dr Dyno).
If Stefan's updating the full version more frequently, that's another reason to convince myself to buy it. I wonder if I can find a list of current releases and dates for both apps - I'll put it on the to-do list.
Thanks for having a look at them; I’m getting into this thread. We’ll be having a few converts before we’re done!
(Will I disturb you if I just email in the morning, or shall I wait until the surgery is open?)
Just putting the Overall Gear Ratio calculation discrepancy to bed, so I can concentrate on playing on me scoot tomorrow; I’ve gone through your calcs from the other day, vespasco, and confirmed that our slight difference was due to using different tyre circumferences as I’d suspected. I’m happy that its right, but here’s a couple of screenshots to show it if you’d like to convince yourself also:
In this first one, I’ve highlighted in RED where you’ve used 1320, and again in BLUE where any figures are the result of using 1320 (obviously that is correct for your scooter anyway). Further down your calcs, you use your 1320 as part of the calculation for my overall gear calculation, which is where we differ. The other area where we differ is those figures in GREEN, where I have kept a fraction, and you’ve used a number to 3 decimal places. With those two matters now checked, my 5.342 is exact for my tyres; and we have the same method, just doing it differently.
The second image shows how the discrepancy comes about, and how we each got our results.
This is a different matter to the question of accuracy of measuring tyres, and also the fact mentioned earlier about tyres changing shape and size during riding. Anyway the conclusion is that you and I are using the same method to get overall gear ratio - and tomorrow i can concentrate on getting some decent Wavs!
Quickly,,, When you can send me the wavs. Im trying to find time to play with different settings. If you have the gsf dyno try using a different filter. Set it to 2 (default is 3 ?) and see if its easier to select the correct spectrum. Im still learning dynos and this app.. and Ive a feeling ive c**ked up somewhere but not had much chance to go through everything again. I think ive sent the wrong wav file! No biggy! Ill sort it. (My PS was the same and i picked the wrong one).. Ill update and edit as required. I also want to get it right once and for all. For the record so to speak. Just may take a little longer than expected. Please chime in anyone, if you know of mistakes ^^^^^^ We have the technology!
And quickly again... Is this anywhere close do you think? Its with all your settings as above (250kg,0.8,0.8,1007,7) and i re checked the tyre size (1355mm) 5.342 o/a ratio Ive been filtering and scrubbing and its the best i could get but the spectrum was not so smooth. Your new wavs will no doubt be more accurate but i thought id give you a teaser. How does this compare to your revs/speed?