How can i calculate 0 to 100 with no speedo ?

[SBSP]

I would like to calculate 0 to 100 km/h in seconds on my motorbike it should be round about 6 secs.
I dont have a speedo and dont know anyone with a GPS,
and i need it to be as exact as possible.

How accurate is specs from manufactures when it comes to Kilo Watts ratings ?
Cus my bike according to honda is 13Kw or should i rather get someone to run it on a dino machine ?

[Prime]

Unless its a $25k gps which is military precision, you won't get accuracy with a gps. Ordinary ones are accurate to between 5 and 15 metres.

[Prime]

Oh and jamin will help you if you do it with a speedo.

[SBSP]

If i get a friend to mark 100Meters with his quad then use a stop watch to take don the time ?

So if i do 100m in 10 secs its 10 meters per second but that would be an Average

[SykomantiS]

Constant speed, yes, but not under acceleration. A Dyno run should be able to do it.

[SBSP]

Constant speed, yes, but not under acceleration. A Dyno run should be able to do it.

Yes but a dyno run would kind of be theory and not real practice.

I dont know how dynos are run, but when they do it do they switch gears ?

[Prime]

...And there losses from friction and wind resistance. Put it on a dyno.

[SykomantiS]

Yes, a dyno does measure the 'ideal' values, not considering wind resistance etc.

Why do you need this much accuracy, if I may ask?

[Prime]

Yes, a dyno does measure the 'ideal' values, not considering wind resistance etc.

Why do you need this much accuracy, if I may ask?

exactly, so take the dyno value as the maximum performance

[WiK1d]

I actually saw this on another biking forum. A guy fitted a bicycle spedo onto his bike. Just make sure it's properly calibrated.

[SBSP]

The Story is.
Some people refer to the Honda CRF230F as a 'Mountain Goat"
Has lots of bottom end tuorqe. And is not designed to be a race bike.

And i can confirm it clims hills easily without having to fight it. I can also confirm that its not a race bike.
My friends 450 DINLI quad wastes me in a straight line.

The bike is also very restricted and lean on fuel/Air mixture
when it comes out of the factory.
Its designed to comply to Euro standards sound polution, emissions ect ect.

The exaust is restricted with a spark arrester to prevent sparks causing a fire in places like a forrest.

I dont care about the noise cus i'm not riding in residential areas or where i'm theretening any animals.
The spark arrester is just a plain dumb idea.

So to take away the leanness you can buy a bigger jetkit from Honda them selves, to let in more fuel.clip it to the correct altitude pos.
And obveously more in means more out, so the Air restrictor underneath the seat has a plug that can pull out.
You also then take out the spark arrester for better flow out.

So i'm basically going to uncork it.
And according to some websites, doing this it will gain performance to a point beyond its suppension capabilities.
And will require you to upgrade the suspension and swop the fork.

After that i will put in a rev box then a better pipe. and a maybe a 51 tooth sprocket.

The jets cost R250 a revbox probably a R1000 and a new pipe +- R3500

Before i do this i want to see hom much performance i have gained out of this.

in Kw and 0 to 100

[SykomantiS]

51 tooth? how big is the stock sprocket?

And I'm guessing it's a stroker? I'm not that familiar with the scramblers.

[SBSP]

I dont know i guess about 48 to 50.

Nope its a 4 stroke, if a stoker is a 2 Stroke.

honda dont have 2 strokes on the market anymore in sa this is a 2008 model

[SykomantiS]

Correct me if I'm wrong, but 4 strokes don't use rev boxes?

They do however, benefit from a free(-er) flowing exhaust.

And just make sure about the sprocket. While it will result in more power at the rear wheel, that combined with decorking the engine as you say, might prove to be too much power at the rear wheel, ie. unusable power. The bike power wheelying in every gear every time you open the throttle might be loads of fun, but it won't do much for racing purposes.

[SBSP]

As far as i know you do get a rev box for a 4 stroke maybe rev boxes for 2 strokes and 4 strikes have different purpose.

It replaces the Standard CDI unit you get a BBR revbox

http://www.regulatorrectifier.com/catal ... -1252.html

[SykomantiS]

Ahhh, that's a CDI. Now I understand. It's not a 'revbox' as in the traditional sense of the word. On a stroker (unless I'm severely mistaken) the revbox is that big bulge in the exhaust pipe which optimises the power output at a specified rev range.

Regardless, I can see what you are planning to do.

As for the original question ---- > Dyno, modify, dyno again, compare.

Edit: You have a local price for those CDI's?

[SBSP]

Ahhh, that's a CDI. Now I understand. It's not a 'revbox' as in the traditional sense of the word. On a stroker (unless I'm severely mistaken) the revbox is that big bulge in the exhaust pipe which optimises the power output at a specified rev range.

Regardless, I can see what you are planning to do.

As for the original question ---- > Dyno, modify, dyno again, compare.

Edit: You have a local price for those CDI's?

Nope not yet i know of someone that has one installed but it was imported.