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1996 Kawasaki KX125/250 V 0.1 by PacoPastor34

Started by pacopastor34, May 13, 2016, 11:35:02 PM

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pacopastor34


Docfumi

Quote from: pacopastor34 on May 22, 2016, 02:44:00 PM
What do you think about the 125 engine?

For me the engine is perfect as well as the handling of the bike. It is very good going in and out of turns.
Really good job on these two bikes.

Cheers  ;D
I didn't lose the race, I ran out of laps.

Asdrael

May 22, 2016, 02:52:10 PM #17 Last Edit: May 22, 2016, 03:08:47 PM by senensis
Thanks for the old school 2 stroke effort :)

Gave a (very) quick spin to the 125. I think it has way too much low end torque - it is too easy to make it flip in first and second gear without the clutch outside of the pipe range. In that regard the CR125 feels much closer to what it should be (even if a bit too tame). Expanding on this - it picks up outside of tight corners without the clutch way too well for a 125.

Edit: the 1st is a bit long, rest of the gears seem on point.
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pacopastor34

Quote from: Docfumi on May 22, 2016, 02:50:56 PM
Quote from: pacopastor34 on May 22, 2016, 02:44:00 PM
What do you think about the 125 engine?

For me the engine is perfect as well as the handling of the bike. It is very good going in and out of turns.
Really good job on these two bikes.

Cheers  ;D
Thanks Doc!
Quote from: senensis on May 22, 2016, 02:52:10 PM
Thanks for the old school 2 stroke effort :)

Gave a (very) quick spin to the 125. I think it has way too much low end torque - it is too easy to make it flip in first and second gear without the clutch outside of the pipe range. In that regard the CR125 feels much closer to what it should be (even if a bit too tame).
I'm agree with you, CR125 feels close to the 2stroke mid-range kick. But I wanted to recreate the full throttle 125 ride style. When you do mx in a 125 you have to quick shift the gears up to get a decent speed. I must tweak that low-end. Thank you so much senensis for the feedback. That's what I need to improve that and next bikes.

Asdrael

Quote from: pacopastor34 on May 22, 2016, 03:08:49 PM
I'm agree with you, CR125 feels close to the 2stroke mid-range kick. But I wanted to recreate the full throttle 125 ride style. When you do mx in a 125 you have to quick shift the gears up to get a decent speed. I must tweak that low-end. Thank you so much senensis for the feedback. That's what I need to improve that and next bikes.

Added a quick edit as you replied.

I see what you mean, but that 125 full throttle style is usually achieved by going through clutches like a mofo :d It's all about reaching that mid range pipe kick asap and keeping it high revs to avoid the bogging down at low rpms. I don't know which power / torque curves you used, but I would suggest a slower ramping up at first, then a steeper curve reaching the mids.
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pacopastor34

I'm gonna tweak that engine in order to get that kick and fix 1st gear.

That's the curve I made.



Thank you again.

Asdrael

This looks like a 250F power curve. For a 125, you are looking at almost nothing (10hp) until 6k RPM. Then it starts picking up. Have a look at this article:
http://www.motorcycle-usa.com/2002/11/article/2002-yamaha-yz125-vs-yz250f-2/
There is a power curve and a torque curve. It's for a '02 125YZ but quite frankly, nothing drastic has changed on MX 2 strokes engines since the addition of liquid cooling. The engine is basically empty until 7k RPM (most dyno you can find go down to 5-6k only, where you have that flat section of the power curve. Below is idle anyway).

This is a RM125 which were at the time known for requiring even higher RPMs: http://www.scalvinipipes.com/ScalviniDyno-RM125.html

I hope that helps. It's more difficult than I thought tracking down the proper dyno charts for those small smockers, but any year between 1990 and 2005 will be in the ballpark.
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Asdrael

Ding ding ding!
1996 125 dyno chart. This is at the rear wheel so for the engine I think you should add 20% approx (YZ is given at 31hp, was 36 factory I think).
http://www.pulpmx.com/sites/default/files/u165/csteel101_10.jpg
https://gyazo.com/dcebdcd0f1dc65d6507504288f7840aa
It starts at 7k, but extrapolating from other data, you have a flat between ~5 and 6.5RPM at 10hp, then it goes down to 5hp in power at 4k RPM minimum and then stalls.
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pacopastor34

Quote from: senensis on May 23, 2016, 08:43:23 PM
Ding ding ding!
1996 125 dyno chart. This is at the rear wheel so for the engine I think you should add 20% approx (YZ is given at 31hp, was 36 factory I think).
http://www.pulpmx.com/sites/default/files/u165/csteel101_10.jpg
https://gyazo.com/dcebdcd0f1dc65d6507504288f7840aa
It starts at 7k, but extrapolating from other data, you have a flat between ~5 and 6.5RPM at 10hp, then it goes down to 5hp in power at 4k RPM minimum and then stalls.

Oh god, that is amazing. Thank you so much , I'm going to work with this  to make it the most accurate. I will contact you before the next releases! ;)


Asdrael

May 23, 2016, 10:35:48 PM #24 Last Edit: May 23, 2016, 10:37:49 PM by senensis
Check your PMs Paco.

I'd be glad to help the 96' fluo 125 revival take place :)
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HornetMaX

Quote from: senensis on May 23, 2016, 08:43:23 PM
Ding ding ding!
1996 125 dyno chart. This is at the rear wheel so for the engine I think you should add 20% approx (YZ is given at 31hp, was 36 factory I think).

How much you lose between the engine (crankshaft) and the wheel is described (in MXB) by the "Efficiency" parameter in the "driveline" section of the bike .cfg file.
For this mod bike it's currently set at 0.92 (i.e. you lose 8% power). 20% transmission loss sounds huge (for road bikes at least, don't know if it's any different for mx bikes).

Asdrael

Quote from: HornetMaX on May 24, 2016, 09:54:17 AM
How much you lose between the engine (crankshaft) and the wheel is described (in MXB) by the "Efficiency" parameter in the "driveline" section of the bike .cfg file.
For this mod bike it's currently set at 0.92 (i.e. you lose 8% power). 20% transmission loss sounds huge (for road bikes at least, don't know if it's any different for mx bikes).

Good catch, thanks for that. 20% is indeed high but given the different values you find and the first full dyno I found (first link, I don't know what they did with it), it matches when you multiply by 1.2. That's why I recommended bumping by 20%.

Still pretty exited by what's coming up next once we dig up more data and modders get a hang of things!
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pacopastor34

Quote from: TheFatController on May 17, 2016, 11:28:57 AM
Having a lot of fun on this bad boy!



THAT GEAR! Nice.

I had a lot of things to do that week. I hope to organise and upload a template very very soon. Sorry for the wait.

ChrisK

the engine now feels realy good but the autoshifting is bad it shifts maybe by 5000-7000rpm.

ya i Need autoshift  rider lean f/b r/l, dabbing, using the clutch, steering, throttle, rear brake front brake is enough for my fingers :D

pacopastor34

Quote from: ChrisK on May 30, 2016, 08:40:38 PM
the engine now feels realy good but the autoshifting is bad it shifts maybe by 5000-7000rpm.

ya i Need autoshift  rider lean f/b r/l, dabbing, using the clutch, steering, throttle, rear brake front brake is enough for my fingers :D

I'm sorry man. I don't use the autoshifting and I don't plan to support that devil thing. :P