Kart Calculator

[itsid]

Is there a site that does what this app does minus the measurements parts... just the mathematicals. I know theres a bunch of separate sites that together will give the info wanted... but how bout an all in one site?... like I said minus the measurements... just the calculations under mathematical processes.

... or is 'that' still under-constuction(on your site) and awaiting your attention?

Well the app technically runs in any environment of course (that's your PC for example) but the 'measurement' part isn't exactly usefull on a non-gps device.
So to reduce loads that was removed already.
And that is a yes.. it's under construction

The problem is that I want to keep the basic layout so that you find all inputs at the very same position as you would on your mobile..
the problem here is the stylesheets are not exactly std.browser compatible,
except for recent chromium browsers NONE renders the page correctly.
So I will have to redo most of it.

I think maybe within 2 weeks or so I will have it working ... hopefully

Thanks Sid...

I got another problem...

If you see my kart, I got engine from scooter, with built TC, i do not now type... But I know that on topspeed it got ratio 6:1 so I selected option tc with jackshaft, but that is not realy what i have...
Still, I love your app
Hopfuly, there is not going to rain today so I can push kart bit more ( slicks and standing water do not mach for some reason )

Thanks alot!
Well, the FXR I know of (130/70x12 (or 130/60-13") rear wheel 145km/h top speed)
has a wheel circumference of ~153 cm, max speed is 40.2778 m/s, so the wheel rpm is 1580;
with an engine rpm of 8000 that's 5.06:1 not 6:1
even if we assume a max speed of 130km/h (the throttled version) that's 36 m/s or 1416 wheel-rpm or a overall ratio of 5.65:1; although that top speed is CDI limited, so you do not get the full 8000rpm but rather 7500 or something (that'd be a 5.3:1 ratio)

Also you said your rear wheel diameter is 25cm that's not a full 10"... all 5" rim wheels I have are 11" (or almost 28cm) so maybe there should be some more measurements


'sid

 

[karte_m0lim]

I found two max speed on net, 136 and 108 km/h for fxr...
I do not put 25cm wheel instead 13", there I put 40 tooth sprocket and another on axle with 28 tooth.
There is my calculations :http://www.diygokarts.com/vb/showpost.php?p=324015&postcount=12

So, what do you think?

 

[itsid]

I found two max speed on net, 136 and 108 km/h for fxr...
I do not put 25cm wheel instead 13", there I put 40 tooth sprocket and another on axle with 28 tooth.
There is my calculations :http://www.diygokarts.com/vb/showpost.php?p=324015&postcount=12
So, what do you think?

the fxr (180ccm) top speed should be 145km/h (not limited;
(there are 130 km/h limiters for some countries)
the fx (125ccm) top speed is 122 km/h
the vx ( fx successor 125ccm) top speed is 108km/h
the vxr (fxr successor 200ccm) has a top speed of 130km/h

ok, new calculations ... on some sites I found that top speed of this bike is 108 or 130 km/h ..
tyre used is 130/60-13''.

so diameter is 13'' + 12 cm which is 45,02 cm or 0.4502 m

Nope... 48.62cm or 0.4862 m
13 * 25.4 + 2*(130 * 0.6) = 330.2 + 156 = 486.2 mm

circumference is Diameter * PI => 0,4502 * 3,141 = 1,413 m

0.4862 * Pi = 1.5274 m...

top speed 108 km/h = 30 m/s
rev on axle = 30/1,413 = 21,77 (1/sec) = 1276 rpm

again 130km/h min more likely 145km/h (36.1 m/s or 40.28m/s)
.......

gokart wheel is 5'' and whole tyre is 10" or 25.4 cm or 0,254 m in diameter

you're sure? 10" diameter.. all I have are 11" *shrugs*

so the calculated result is:
KartInfo by kartcalc.net:

[FONT="Verdana"]
[B][U]KART[/U][/B]
[INDENT][I]RW diameter[/I]: [B] 25.4 cm | 10 in[/B]
[I]Total weight[/I]: [B] 210 kg | 462.97 lbs[/B]
[/INDENT]
[B][U]ENGINE[/U][/B]
[INDENT][I]Original HP[/I]: [B] 18[/B]
[I]Asummed HP[/I]: [B] ~18[/B]
[I]Torque[/I]: [B] 16.02 Nm | 11.82 ft lbf[/B]
[I]RPM[/I]: [B] 8000[/B]
[/INDENT]
[B][U]TRANSMISSION[/U][/B]
[INDENT][I]Final ratio[/I]: [B] 4.35:1[/B]
[I]TC type[/I]: [B]  unknown[/B]
[I]Lowest ratio[/I]: [B] 10.88:1[/B]
[I]Highest ratio[/I]: [B] 4.35:1[/B]
[/INDENT]
[B][U]PERFORMANCE[/U][/B]
[INDENT][I]Max Wheel Torque[/I]: [B] 174.3 Nm | 128.56 ft lbf[/B]
[I]Min Wheel Torque[/I]: [B] 69.69 Nm | 51.4 ft lbf[/B]
[I]Acceleration[/I]: [B] 3.92 m/s² | 12.86 ft/s²[/B]
[I]Top Speed in[/I]: [B] ~6.12 seconds[/B]
[I]Top Speed[/I]: [B] 88.05 km/h | 54.71 mph[/B]
[/INDENT]
[/FONT]

'sid

 

[karte_m0lim]

Ok, thanks...

Will fill yor data and do the test...

edit: checked, rear wheels really are 25-26 cm ...

 

[BirdFanatic]

I have a cvt how do i add that into the mix it has no teeth

 

[landuse]

I have a cvt how do i add that into the mix it has no teeth

You do not factor in the CVT. All you look at is the axle sprocket and the sprocket on your TC

 

[BirdFanatic]

You do not factor in the CVT. All you look at is the axle sprocket and the sprocket on your TC

Lol there is not axle sprocket my malibu does not have one.

 

[itsid]

depends if the differential has a gear reduction or not (mower diffs have not, most car diffs do)

and then add that reduction (or 1:1) as the chain ratio.

say it's 3.4:1, 10T cvt and 34 axle sprocket.. etc.pp (or 10:10 of course)

'sid

 

[BirdFanatic]

lol it came out to 179.71km/h = 111 mph saying i will reach full speed in 7.59 seconds lol

 

[itsid]

yeah you will not.. I have no idea why that number is showing again (must have missed to disable the trigger last time I needed it )
That's purely fictional for a TC anyways
(it assumes max acceleration over the full range.. and that's impossible. I just need that number further down the road.. that's all)

keep in mind that your TC is not listed in there and thus the TC ratios mentioned are more or less fictional (a guess, no more)
(assume 2.5 low and 1 high gear) so do not rely on the gear ratio values

Oh btw.. what did you set as your diff ratio; please don't say 1:1 since I'm almost sure it's NOT!

'sid

 

[BirdFanatic]

yeah you will not.. I have no idea why that number is showing again (must have missed to disable the trigger last time)
That purely fictional for TC (it assumes max acceleration over the full range.. and that's just impossible.)

keep in mind that your TC is not listed in there and thus the TC ratios mentioned are more or less fictional (a guess, no more)
(assume 2.5 low and 1 high gear) so do not rely on the gear ratio values

Oh btw.. what did you set as your diff ratio; please don't say 1:1 since I'm almost sure it's NOT!

'sid

I set it to what you told me to set it to
say it's 3.4:1, 10T cvt and 34 axle sprocket.. etc.pp (or 10:10 of course)

 

[itsid]

Yeah.. I don't know it's ratio..
that's an example.. just convert the ratio (most likely a decimal) to a full number.
if your diff has a 2.7:1 ratio, a 7:1 ratio a 3.4:1 ratio... IDK!

So, whatever that is.. times ten for the axle and ten for the sprocket

'sid

 

[BirdFanatic]

Yeah.. I don't know it's ratio..
that's an example.. just convert the ratio (most likely a decimal) to a full number.
if your diff has a 2.7:1 ratio, a 7:1 ratio a 3.4:1 ratio... IDK!

So, whatever that is.. times ten for the axle and ten for the sprocket

'sid

Lol and i have no idea what mine is set to nor do i know how to find out what its set to i believe its a 102c comet
It does not engage like a torque converter its very slow when i step on the gas it leads me to think its worn out

 

[karte_m0lim]

Sid, what values have to put for 5 speed motorcycle engine?

Thanks...

 

[BirdFanatic]

I wonder what my kt100 would do i believe they run about 10000 rpm i have 12 inch tires 82 teeth on sprocket and 10 on clutch

 

[itsid]

Well let's start easy first..

Bird, create a new kart, and set ANY HP value and rpm you want (say 20hp 10000rpm) do NOT tick the "governor removed" checkbox.

set all other values as precise as possible.

Once that kart's in your device's database you reopen it and click on the tacho button on the bottom menu.. take it for a ride..
max it out if you can...
it'll present you the best rpm guess (as well as HP guess) I can do with nothing but a mobile phone.

Now, note those values down somewhere... create a new kart, with those HP and rpm ratings, then all the other values like before.

you can now take it for another run to compare the two runs.

Now the hard part..
This calculator is not made for gearboxed engines, motorcycle engines, not even non-shifting 2stroke kart engine to be honest (but those are at least single speed and thus calculateable)
and it's not meant to work on electric motors as well..

Anyways, you can cheat a bit..
First, make sure you know primary and secondary reduction ratios of your engine,
and the final (chain) ratio of course...
Now find the reduction ratio for your first and last (fifth) gear.

multiply the ratios to get the overall ratio for first and fifth gear. (those two are important)
Now create two seperate karts in your DB.. one for first and the other one for fifth gear.

Take the first gear-entry and do a testrun.. stay in first as long as possible, the moment you need to shift to second hit the brakes and stop the recording.. and you'll be left with a nice acceleration value and a crappy top speed value.

repeat for fifth gear, except go all the way to max speed.. then you have a top speed rating and a somewhat lousy acceleration value (just take that from the first run)

the HP ratings should be at least close, the closer they are, the more precise the reading was.

Precision is based on GPS signal quality.. I can't do anything against it.
But as soon as I have time again to improve the code I will try to test slightly different code to see if there's room for improvement of the code.

'sid

PS Sorry.. but that's a non-profit-hobby-project, so it's priority is relatively low

 

[Badot]

Precision is based on GPS signal quality.. I can't do anything against it.

Just curious, how accurate are the accelerometers in phones? Even if they're not great I bet you could use them to smooth the jitter I assume you get from GPS.

 

[BirdFanatic]

Well let's start easy first..

Bird, create a new kart, and set ANY HP value and rpm you want (say 20hp 10000rpm) do NOT tick the "governor removed" checkbox.

set all other values as precise as possible.

Once that kart's in your device's database you reopen it and click on the tacho button on the bottom menu.. take it for a ride..
max it out if you can...
it'll present you the best rpm guess (as well as HP guess) I can do with nothing but a mobile phone.

Now, note those values down somewhere... create a new kart, with those HP and rpm ratings, then all the other values like before.

you can now take it for another run to compare the two runs.

Now the hard part..
This calculator is not made for gearboxed engines, motorcycle engines, not even non-shifting 2stroke kart engine to be honest (but those are at least single speed and thus calculateable)
and it's not meant to work on electric motors as well..

Anyways, you can cheat a bit..
First, make sure you know primary and secondary reduction ratios of your engine,
and the final (chain) ratio of course...
Now find the reduction ratio for your first and last (fifth) gear.

multiply the ratios to get the overall ratio for first and fifth gear. (those two are important)
Now create two seperate karts in your DB.. one for first and the other one for fifth gear.

Take the first gear-entry and do a testrun.. stay in first as long as possible, the moment you need to shift to second hit the brakes and stop the recording.. and you'll be left with a nice acceleration value and a crappy top speed value.

repeat for fifth gear, except go all the way to max speed.. then you have a top speed rating and a somewhat lousy acceleration value (just take that from the first run)

the HP ratings should be at least close, the closer they are, the more precise the reading was.

Precision is based on GPS signal quality.. I can't do anything against it.
But as soon as I have time again to improve the code I will try to test slightly different code to see if there's room for improvement of the code.

'sid

PS Sorry.. but that's a non-profit-hobby-project, so it's priority is relatively low

I cant even ride it yet i was just wondering what the calc said it was able to do.

 

[itsid]

Just curious, how accurate are the accelerometers in phones? Even if they're not great I bet you could use them to smooth the jitter I assume you get from GPS.

The accelerometers are actually WORSE!
And no I don't do sensorfusion with my code..

allow me to explain a bit better.
Sensorfusion is what you're talking about,
taking all the values of each sensor (GPS, accelerometer, gyroscope)
and combine them to get smoothed, nearly jitterfree data for whatever value you want (one sensor smoothes another).

And while this works very nicely in an application you download from the appstore/playstore
it's a real pain in javascript, not because I don't know how,
but because the sample rate is insane,
thus the amount of memory needed and worse the CPU power needed to do that in a webapplication is insane too.
I drained my ~90% battery to below 25% in less than 30 minutes on my iPhone 4S;
and that's inacceptable!

And the odd thing, while the Dyno-graphics are much better with sensorfusion, the final result has only a 4-5% higher accuracy in most of the testruns
(Okay, I wasn't very scientific with the testruns..)
But still, sensorfusion was removed.

The accelerometer at least on the devices I tested with is a real sissy...
the slightest bump in the road can read as insane acceleration,
so I still remove jittering in a very basic manner
(change ratio limiting)

That code is marked for further improvement though, I'm not too happy with it to be honest.
But again, it's only a webapplication,
so I have to rely on javascript and it misses a bit of the performance compared to say C-code;
That's why I need to keep my code as small and fast as possible to compensate for the lack of rendering speed.

Maybe one day I will go the extra mile and make it a real App,
Appstore/Playstore to allow further improvements.
but not now, not even any time soon I'm afraid.

'sid

 

[karte_m0lim]

thanks , so I was close ..

i thought that I have to do it for all five gear ratios

should I put combined gear ratio (engine gearbox gear ratio + my sprocket ratio and use jackshaft or general (combined) ratio )?
I asking this, because, does jackshaft calculate some lost or it's just there to make easier for jackshaft users to insert accurate data?

anyway, this is great app , good tool, shame that there is no more karts in library.