Has anyone here had their pitbike Dyno'd ?

[my67xr]

i was just wondering, has anyone had their pitbike on a Chassis Dyno before?
and have you got any HP/Torque graphs printed out ?


how was your bike set up?
eg Motard wheels ? gearing ? what size engine ? etc
did you change any components, then do a comparison run on the same day?



one of my future projects is to make up a a very basic Tuning Dyno.
it will be portable, and take only a little power/electricity to run it (generator maybe ?)
i will fit a variable load to it, to simulate real time riding.
and might add an O2 sensor, Temp gauge, Tacho and Speedometer.
i think it'd be a good thing to help tune your bikes, and also for troubleshooting purposes.
great for jetting, timing, comparing coils, cdi units, and then for general bike tuning/running....


i know a couple of people with Dyno's, and i might speak to them about my idea too.
hmm,
i wonder if we could get enough members here with bikes that would bring them down and have a Dyno day somewhere ?
i would need to speak to the shop owners and see how much it'd cost to put our bikes on and give them a power run.
i put my car on the Dyno a few years ago at a dyno day set up by one of the ford forums i frequent.
it was a great day, they had a bbq and drinks available, entry was about $50 per person.
there were no engine fatalities on the day either, but that may be something to think about too, just in case bikes aren't jetted/timed properly etc
a quick preliminary dyno run would show these problems up though.



the reason i want to make my own, is i cant afford to have my bike done professionally atm.
and i don't have a big area (anymore) to tune my bike either.



what are peoples thoughts ?



cheers, craig

 

[timeeh]

I got mine dyno'd at a dyno day. $30 for a run. Normally it's around the $1-200 mark but that includes the tune. I put a slick on the rear as if you run them with a nobby it gives bad/false readings. Mine (as previously discussed) came in extremely rich, i would of liked to run a second run but time did not allow for it as I would of had to put my name back on the list right at the bottom and wait till everyone else had their runs But gave me a good starting point as i know where to aim now.

 

[timeeh]

And yea would lov another dyno day, but sorry mate I aint gonna travel to SA just to dyno

 

[my67xr]

thanks timeeh,
i remember seeing yours a while ago i think? if you get a chance could you repost it ?

 

[timeeh]

Just for you mate

 

[my67xr]

cheers, it will help me work out what sort of readings etc i need

 

[timeeh]

Dotted line that runs straight (nearer the bottom) is the nuetral line for lean/rich. Then the green and red are first and second runs (the second run was without a filter) as you'll notice the first run the horsepower is very down + the air/fuel line runs flat across the bottom, meaning that it was so rich the machine could not pick it up. The second run it starts to lean out (almost perfect) from 9-10.5k. If that all makes sense, unfortunatly the way they had the machine setup this time did not include tourque, not sure as to why?

 

[Shearer]

Had few bikes pot on dyno over at cessnock couple years ago.
brothers stocka 1 1/4 hp , mates tb 88 limited 5.5hp , tb117 storker motor had in crf setup 12.5hp. of top of me head they where , tying to find pictures of bikes on dyno n chart print out! not haven much luck . not shore where pot them.

 

[my67xr]

thanks Shearer,
wow. i didn't realise a dyno could read that low, 1 1/4 hp, that's modern technology hey !

 

[rumble]

Maybe you could start with a real basic roller 'dyno'. Think Terry had one or linked it but it just had a disk brake attached to the rollers with a weight pulling down on the brake pads.... prob more for just hear how it sounds dyno

 

[Shearer]

thanks Shearer,
wow. i didn't realise a dyno could read that low, 1 1/4 hp, that's modern technology hey !

Only had stocka on the dyno for like 2min max!, gave it one run, then the hockie strap that was holding exhaust analyser. got hook up in rear wheel raping around, inturn pulld wires off!! dude went off this head!. we like hay wait watt hp see read. said mmmm 1 1/4. didnt get print out.
wasn't our fualt mate done it himself.

 

[my67xr]

mine will be just basic until i get it sorted, i just need to simulate riding up a slight incline in 3rd or 4th gear.
a brake on the rollers would be ok, but the friction will cause the pads to over heat, then it will need cooling fans, lots of disc pads, etc etc

i have a couple of ideas for putting a decent load on the engine.
one is magnetic force, which is pretty good as there is little heat generated under load.
and it has no need for electricity, good for tuning on site.

the other is with an electric motor, and a variable high amperage power supply.


lol shearer,
some people don't always follow the correct procedures when doing mechanical work, dynos etc.

i had my XR on the Dyno years ago, not strapped down.
we needed 4 of us sitting in the boot, just to get some traction tyres to the rollers.
on the previous power run i lost 3mm-4mm of tread from wheelspin.

 

[ClassicHonda50]

Dyno Design Information

Here is some dyno design info:

http://dtec.net.au/Inertia Dyno Design Guide.htm

http://hewittsinertiadynos.wordpress.com/

http://performancetrends.com/tdkmotorsports/index.html





Cheers

Jaimie

 

[Phil67]

Craig, look into powder brakes, some machinery use them, quite effective and reasonably cheap

 

[my67xr]

Thanks for the links and ideas guys.
I had thought about using an electric clutch of an automotive A/C compressor.
and using an adjustable power supply to vary the load on the rollers.
The biggest thing holding me back will be my budget.
atm it will have to be the cheapest way possible.

i have a couple of friends of the family that mighht be able to help me out too.
one owns his own Dyno/tuning shop,
His home made dyno uses an old adelaide tram electric engine.
the other friend is into both steam and electric powered transport.
he is known worldwide for some of his inventions.
he has also converted a few cars now to electric, and uses one for his daily transport.
And my old man is an electronics technician (retired)
it should be a fun project, i'm sure i'll have lots of problems during the build, and learn lots of new things too.