ESE's works engine tuner

[Frits Overmars]

23 mm is ok for a 125.
the 1st series of jollymoto for 250 rgv (125 twin) had a 19 mm stinger which caused a lot of engine failure before moving to 22 mm.
I maintain that 11.6 or 13mm is too small for a 50cc that produces some power.

I wrote that a maximum power of 13.9 crankshaft-hp requires an 11,6 mm end restrictor diameter. I also wrote that 13.9 hp is about 10 hp below the current 50cc top level.
Now what is your definition of' "a 50cc that produces some power" ?

As for the RGV250 example: a well-prepared RGV250 engine can produce about 70 hp at the wheel or about 40 crankshaft-hp per cylinder.
This requires restrictor diameters of 3,1 x Square(40) = 19,6 mm and stinger diameters of at least 1,2 x 19,6 mm. You do the math again?
PS: it may be useful to make a clear distinction between restrictor diameter and stinger diameter.

[skako]

Hi,
I want to thank Frits for the additional comments.
After this I made minor changes to the pipe, by A.I. designed for the AR93.
The obtained characteristic is much better.

yatasaki,
here I transferred the characteristics of the standard Tomos gearbox to the graph.
It can be seen that the gearbox fully utilizes this power in the graph.
Good elasticity for your ride, on the kart track in VT.

[Vannik]

here I transferred the characteristics of the standard Tomos gearbox to the graph.
It can be seen that the gearbox fully utilizes this power in the graph.
Good elasticity for your ride, on the kart track in VT.

Try to model it in the vehicle performance part of Post2T and also show the Power Range as done in Post2T.

[jfn2]

TZ350
If I remember correctly to use these hooks it's better to have plugs in the piston pin ends. If not the shallow hooks are better. If I remember correctly???

[yatasaki]

[QUOTE=skako;1131223231]Hi,
I

yatasaki,
here I transferred the characteristics of the standard Tomos gearbox to the graph.
It can be seen that the gearbox fully utilizes this power in the graph.
Good elasticity for your ride, on the kart track in VT.

Red curve from other graph is which I like, it would suit smaller carburetors and angles we use. I found belly diameters larger than 80mm not benefitial in our applications.
If using FOS concept you have to use different coefficient for belly diameters.
But as Frits mentioned FOS concept is general starting point.

[skako]

Try to model it in the vehicle performance part of Post2T and also show the Power Range as done in Post2T.

Hi Vannik,
I tried to put something together from Post2T.
I'm not sure if you meant this or something else.
The longest straight section of the trail in VT is approx. 115 m.
They occasionally race here with Tomos mopeds.



OK I see now, I will make an addition.

[Frits Overmars]

Skako, if you rev the engine to its maximum rpm in each gear, you are not using all the available power. If you upshift not at the black, but at the green vertical lines, where the curves intersect, you get the yellow parts of the available power as a bonus.

[skako]

Skako, if you rev the engine to its maximum rpm in each gear, you are not using all the available power. If you upshift not at the black, but at the green vertical lines, where the curves intersect, you get the yellow parts of the available power as a bonus.

I know this because near the end of RPM the difference in available engine power is zero.
The power equalized with all driving resistances (air resistance, rolling resistance).
It is ideal, as you say Frits, to jump into a higher gear just before the end of the RPM at the moment when the power difference becomes equal to the initial power in the higher gear.
In the attached graphs horizontally, from the right curve to the adjacent left curve, you can see how much the RPM drops in a higher gear.
The graph below shows the excess engine power in top gear over the required power at those RPMs.
In the attached graphs, I have drawn the characteristics of three gearboxes.
Standard 5 speed, sport 5 speed, sport 7 speed.
I can only say that this 7-speed sports gearbox is not at all comfortable for everyday traffic around town. It's great when you need to accelerate.
Great traction and acceleration. But when the vehicle in front slows down a bit, you almost regularly have to downshift two gears.
In heavy traffic it becomes very irritating for the driver.
However, on a road with slightly less traffic, it's real enjoyment and melody from a small 50cc engine.

Attachment 354448

Somehow the final speed of 135 km/h in the earlier post seems too optimistic to me. I kind of trust my conservative chart more. It is closer to the reality of the required power and speed of a moped.

[jbiplane]

Hello folks. After some experience with Megasquirt and Speeduino I create my own digital injection and ignition board.
2ign +2inj channels 2layers 36x50mm ECU which consists of 80% components produced in Russia and 20% of Chinese components.
100% local possible but would increase PCBA size to 42x58mm.
The board in next version planned to be a bit smaller and completely integrated into throttle body.

New version will reworked for other 7.5x7.5mm Russian processor, working at -40...+85C

Rewritting math as well to be suited better for 2-strokes.

[SwePatrick]

A little collage of my injectionbuild.
I actually got it working really good now when changed the fuelstrategy from only tps based, to tps and pipe pressure.
Still based on tps, but fuel compensated against pipe pressure, works really really nice.
In the future i might also compensate ignition some also against pipe pressure.
Look around in my youtube channel, there are video of dynoing all the way to a little mishap(crank seized)
But parts are ordered already =)

[ceci]

A little collage of my injectionbuild.
I actually got it working really good now when changed the fuelstrategy from only tps based, to tps and pipe pressure.
Still based on tps, but fuel compensated against pipe pressure, works really really nice.
In the future i might also compensate ignition some also against pipe pressure.
Look around in my youtube channel, there are video of dynoing all the way to a little mishap(crank seized)
But parts are ordered already =)

Just a suggestion, have you considered the possibility that a non-mapping injection would be better?

[jbiplane]

A little collage of my injectionbuild.

My project is only started and my exhaust system for amateur aircrafts and paramotors rather primitive.
It will be long way to achieve results. May be to the end of the year. But I will try implement all essential ideas.
The problems I encountered to the moment:
- dynamic performance of fuel injectors are complicate and not so primitive like in math of Megasquirt and Speeduino
- software make wrong fuel correction it themperature below -18
- wrong fuel corrections on altitudes more than 2000meters
Will try find couple of good students and give them to implement some math

Just a suggestion, have you considered the possibility that a non-mapping injection would be better?

I open to all ideas. You meant some kind of many dimensional interpolation?
In my first experiences I playing with exhaust gases themperatures making them stable about 650C instead of use Lambda.

[skako]

try to model it in the vehicle performance part of post2t and also show the power range as done in post2t.

I did it with Post2T and it's good that there is a Power Range in Post2T. I transferred the characteristic power points to excel and made my specific diagrams related to the gearbox. In them I can see the same data better. I will try to describe the method through graphs. There are more graphs to explain what they represent and how to read them, but I can only post 6 of them in the post.

[ceci]

My project is only started and my exhaust system for amateur aircrafts and paramotors rather primitive.
It will be long way to achieve results. May be to the end of the year. But I will try implement all essential ideas.
The problems I encountered to the moment:
- dynamic performance of fuel injectors are complicate and not so primitive like in math of Megasquirt and Speeduino
- software make wrong fuel correction it themperature below -18
- wrong fuel corrections on altitudes more than 2000meters
Will try find couple of good students and give them to implement some math


I open to all ideas. You meant some kind of many dimensional interpolation?
In my first experiences I playing with exhaust gases themperatures making them stable about 650C instead of use Lambda.

Use a method that YAMAHA patented and is now available. It's very simple (if the reeds are curved, the injectors inject)

[skako]

Here are three more graphs to complement the explanation in the last post. The engines are adjusted to have the same final vehicle speed that requires the same power. All further comparisons are made from that point.