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March 29, 2024, 02:29:20 PM

JJ2S X4 500 Motorcycle

Started by Furious, December 22, 2014, 08:34:09 PM

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Vini

Quote from: HornetMaX on December 23, 2014, 12:16:20 PMFor big road/track bikes however, 2 strokes seems to be dead for good.

Well, at least my RGV 250 is still alive :D

Furious

I need some help with this. I got it modelled as few independent files of the bike. Those parts that move separately like wheels, steer, lower suspension and chassis. It's damn too high poly so I will be reducing it. But I work in blender and the fbx2edf doesn't work for me at all (or there is slight possibility that I don't know to use it properly) and there is still not finished tutorial site.
So, here comes the question, how do I give colour to parts of the bike?
How can I decide which part of the bike will be able to repaint with .pnt file ? How do I create textures on certain surfaces? Can I just assign texture in blender and export the file? Will it export within .edf file? Do I have to use specific type of texture (with specular map and bump map)? Can I use materials from blender?

I know those are simple questions, but I only started to learn 3D modelling  and even I'm happy with the shape I can't proceed :/

JJS209

i've found a EdfExp2010p.dle for 3ds Max 2010 if that would solve your exportingproblem when u will use 3ds max for export?!

plugins -> EdfExp2010p.dle

EdouardB

Quote from: JJS209 on December 23, 2014, 09:55:22 AM
i think the "old" 2 stroke motogps have had something around 160bhp and the "problem" of these realtive big 2 strokes is the performance explosion.
you can watch a trailer of "the unrideables" on youtube.

More than that actually. Here are the numbers that have been verified for 2 stroke GP factory bikes at the crank right before they were banned:
- 125: 54bhp
- 250 : 106-110 bhp
- 500: about 190-200 bhp

To be honest the power wasn't increasing much anymore at the end of the 2 stroke era. The Aprilia RSW125 stayed at 54 bhp for a few years.

Here is the power for production racers (Yamaha TZ, Honda RS):
- 125 : about 40/45 bhp
- 250 : about 85/90 bhp depending on the year - weight is about 102kg dry on a 250TZ
- 500: production racers were abandoned fairly early, so we don't have a good comparison.

HornetMaX

Quote from: EdouardB on July 08, 2015, 09:30:02 AM
To be honest the power wasn't increasing much anymore at the end of the 2 stroke era. The Aprilia RSW125 stayed at 54 bhp for a few years.
Because on a "simple" 2 stroke (no valves, no direct injection etc), there's not that much you can do after a given point.

For the 500cc, the other (and maybe even more important reason) is that usability was becoming more important than peak power: better to have 5cv less but with a less abrupt delivery. Faster laps and less broken bones. The latter being probably more important than the former :)

MaX.

EdouardB

Quote from: HornetMaX on July 08, 2015, 09:44:36 AMno valves
Your message is spot on except for this part. The factory YZR500 for example used YPVS exhaust valves a lot. First they were mecanically driven, but on the later YZR500 (1986 and after) the valves were electronically driven by the CDI and the bikes actually started having small batteries next to the dashboard for the valves!
The YPVS was a noticeable improvement to exit slow corners (1st gear, mid RPM). For the rest of the powerband, not so much (basically open all the time), but hey, even if you get the smallest advantage, it's worth it at this level.

HornetMaX

Right, exhaust valves were used. But they were more of a (very effective) tuning aid than valves as in a "valved engine" (where admission/expulsion are dictated by the valves).

MaX.

Allen

The 1980 Rotax 256 was supposed to produce 50KW.. that's just 67bhp
(but then the 1980 TZ250G was only supposed to put out 55bhp)

Of course you could then change the carbs, disc valves and exhaust to completely alter the way it developed that power

Friend of mine ran a Harris Rotax in an international classic 250 series a couple of years back.. 1984 256 engine with power valve, ran 60 bhp at the rear wheel on a dyno.


Allen

Quote from: HornetMaX on July 08, 2015, 11:33:32 AM
Right, exhaust valves were used. But they were more of a (very effective) tuning aid than valves as in a "valved engine" (where admission/expulsion are dictated by the valves).

MaX.

Consider the power valve system to be like a variable valve timing in a 4 stroke, all it does is change the outlet open period, shorter opening and lowering the top of the exhaust port = less power

HornetMaX

Quote from: Allen on July 08, 2015, 11:42:16 AM
Quote from: HornetMaX on July 08, 2015, 11:33:32 AM
Right, exhaust valves were used. But they were more of a (very effective) tuning aid than valves as in a "valved engine" (where admission/expulsion are dictated by the valves).
Consider the power valve system to be like a variable valve timing in a 4 stroke, all it does is change the outlet open period, shorter opening and lowering the top of the exhaust port = less power
Nice analogy. Not as flexible though (but not as complex neither).

MaX.

Allen

Actually it was a slightly bad description as what it does is flatten the torque curve by improving the mid range when the power valve is at it's lowest position and as the revs rise it opens the valve, thereby increasing the open time and effectively moving the torque up the revs to match. The height of the ports define where in the rev range the torque curve lies (quick and dirty tuning on old two stroke road bikes was to add a second base gasket and machine and equal amount off the head, that raises all the ports, moves the torque curve up the revs, more revs for an amount of torque = more power) so effectively you are moving the torque curve by changing the port height and so making the torque curve flatter and wider..

Vini

July 08, 2015, 03:24:23 PM #41 Last Edit: July 08, 2015, 03:57:30 PM by vin97
I just don't understand your problem with two-strokes, Max.


Of course there is a point where you cannot get anymore power out of the engine but at that point it will still produce at least 1.5 times the power of a highly tuned four stroke of similar displacement without needing camshafts, valves or a wet sump.
How is the independence from such things a bad thing??

HornetMaX

Quote from: vin97 on July 08, 2015, 03:24:23 PM
I just don't understand your problem with two-strokes, Max.
I just motivated why the max power was stagnating towards the end of the era, nothing more.
That said, they definitely had more than enough power for the time :)

Quote from: vin97 on July 08, 2015, 03:24:23 PM
Of course there is a point where you cannot get anymore power out of the engine but at that point it will still produce at least 1.5 times the power of a highly tuned four stroke of similar displacement without needing camshafts, valves and a wet sump.
How is the independence from such things a bad thing??
It's not a bad thing, it's a great thing of course. But it comes at a price in other areas.

A simple engine is good from many points of view, but it will reach some limitations (power, emissions, max rpms, whatever) to go beyond which one will need to make it more complex.

MaX.

Furious

I'm happy that everyone have nice conversation about 2 strokes, but I need a litle help with putting this 2 stroke into the game ;) Really no one is able to answer these questions? How all those mods came up then?
Quote from: Furious on July 05, 2015, 08:32:48 PM
I need some help with this. I got it modelled as few independent files of the bike. Those parts that move separately like wheels, steer, lower suspension and chassis. It's damn too high poly so I will be reducing it. But I work in blender and the fbx2edf doesn't work for me at all (or there is slight possibility that I don't know to use it properly) and there is still not finished tutorial site.
So, here comes the question, how do I give colour to parts of the bike?
How can I decide which part of the bike will be able to repaint with .pnt file ? How do I create textures on certain surfaces? Can I just assign texture in blender and export the file? Will it export within .edf file? Do I have to use specific type of texture (with specular map and bump map)? Can I use materials from blender?

I know those are simple questions, but I only started to learn 3D modelling  and even I'm happy with the shape I can't proceed :/

Alone

Hi Furious

Here is one of the bests tutorials I founded from 3D basics. Hope it helps.

http://www.3dtotal.com/ffa/tutorials/max/joanofarc/joanmenu.asp