ESE's works engine tuner

[Wos]

I´ve got a couple of questions for you guys that have converted your rides to EFI.
In what manner do you add fuel 'when on pipe'?

Compensation relative to crankhouse pressure, or pipe pressure?
Either way, do you use any sort of 'pulse damper device' between source and map sensor?
I reckon the map sensor will live a hard life otherwise.

Rgds
Patrick.

A little video of some of the parts i made and will run:
(nevermind the AMG in the beginning, just an intro)

Nice CNC parts Patrick 👍

In map sonsors can only talk about of KTM 990 4 stroke twin used in mainfold there.
No clue how fast readings of Equipment in this case are. gained about 20 HP by getting rid of the limitations KTM set in injection and ignition timings 🙈🤪

The Ecu is reading the sensors values and is giving decreasing influenz of the two MAPs the higher engine is reving.

In higher revs main influences on injection durations are fix given in table, corelated from values of TPS opening and RPM.
MAP values only have 10 percent influence there.
This is kind of damping in ECU

Think this is the way to go cause you are free to set necessary pulse damping even when pulses are hard and sensor to slow 🤔😉✋

Pure mechanical damping can be done by🤔

Length of hose
Its stiffnes
Its diameter

Avoid overheating sensor🤔

Take care about the fact, that temperature is changing stiffnes off diffrent hose materials ..maybe use metal tube in hot areas


GRÜßE Wolfgang

[TZ350]

I´ve got a couple of questions for you guys that have converted your rides to EFI.
In what manner do you add fuel 'when on pipe'?

Compensation relative to crankcase pressure, or pipe pressure?

MAP, (Manifold Absolute Pressure) is a four stroke thing that has no equivalent in normal two stroke motorcycles. You cant put a MAP sensor on the inlet tract of a two stroke and have it work like it does on a four stroke.

Use Alpha-N (Throttle-Position / RPM) for every where you are on the pipe. But for trailing throttle into a corner, use VE (Volumetric Efficiency) for that and coming back onto the pipe as you exit the corner, MAP / VE.

For a two stroke, MAP can be approximated by the Difference between Max and Min crankcase pressure each cycle. This "Difference" varies with engine load and power output. More power or on the pipe, bigger difference than when throttling off, or trailing throttle.

Some Two Stroke EFI stuff:-

https://www.kiwibiker.co.nz/forums/s...50-EFI-Special

https://www.kiwibiker.co.nz/forums/s...2T-EFI-Project

Common MAP sensors put out their reading in one milli second bursts. This is what the MAP sensor reading the crankcase pressure on a 125 looks like. Purple line, Yellow line is the Ignition trigger.

1,800rpm 4,000rpm 10,000rpm

I used an Arduino Nano to find the Difference between the high and low reading each cycle and converted the Difference using a Digital to Analog card to get something that looks like a normal four strokes MAP value to feed into the EFI's CPU.



Alpha-N gets used everywhere that it is on the pipe, or definitely not on the pipe. I.E., us Alpha-N when the load is predictable. MAP and VE is used where the pipe is not sure if it is "On" or not.

If you are running Alcohol fuel I would not worry and just use the Alpha-N topology everywhere.

[Wos]

MAP, (Manifold Absolute Pressure) is a four stroke thing that has no equivalent in normal two stroke motorcycles. You cant put a MAP sensor on the inlet tract of a two stroke and have it work like it does on a four stroke.

Use Alpha-N (Throttle-Position / RPM) for every where you are on the pipe. But for trailing throttle into a corner, use VE (Volumetric Efficiency) for that and coming back onto the pipe as you exit the corner, MAP / VE.

For a two stroke, MAP can be approximated by the Difference between Max and Min crankcase pressure each cycle. This "Difference" varies with engine load and power output. More power or on the pipe, bigger difference than when throttling off, or trailing throttle.

Some Two Stroke EFI stuff:-

https://www.kiwibiker.co.nz/forums/s...50-EFI-Special

https://www.kiwibiker.co.nz/forums/s...2T-EFI-Project

Common MAP sensors put out their reading in one milli second bursts. This is what the MAP sensor reading the crankcase pressure on a 125 looks like. Purple line, Yellow line is the Ignition trigger.

1,800rpm 4,000rpm 10,000rpm

I used an Arduino Nano to find the Difference between the high and low reading each cycle and converted the Difference using a Digital to Analog card to get something that looks like a normal four strokes MAP value to feed into the EFI's CPU.



Alpha-N gets used everywhere that it is on the pipe. VE is used where the pipe is not sure if it is "On" or not.

If i had these experts words👍🤩

If you put pressure sensor to pipe in a 2 stroke?... there is absolutely no usable signal, to recognice ...we are on or off pipe?

Thanks to experts! 👍😎

Wolfgang

[Pursang]

I have tried the thermo housing at the intake side on the bottom of a couple of racebikes.
Maybe the thermo element body was a bit small , but in both cases the hot running temp ( fully closed bypass ) was a few degrees higher
as I think even a small restriction on the pump inlet side has a large effect , Whereas any restriction seen on the pressure return side has little effect on the flow efficiency.

Hi Wobbly, I'm not sure I understand?? In the Bennett system, the bypass is always Fully Open.
The thermostat element is constantly exposed to the bypass flow.
At it's design temperature it opens to allow input of coolant from the radiator (Flow through the thermostat valve is reverse)
Opening temperature of the thermostat element may need to be varied to achieve the desired max operating temp.
Mixing chamber volume, flow path and/or thermo element shielding are design considerations.
The bypass hose diameter and top diversion junction should be configured to provide minimal restriction to the pump input.

Bennett found that a stable operating temperature was essential to achieve optimum combustion efficiency in 150+ kg of Cast Iron.
I expect it is infinitely more critical in a couple of kg of aluminum with more holes than metal.

[SwePatrick]

Nice CNC parts Patrick 👍

In map sonsors can only talk about of KTM 990 4 stroke twin used in mainfold there.
No clue how fast readings of Equipment in this case are. gained about 20 HP by getting rid of the limitations KTM set in injection and ignition timings 🙈🤪

The Ecu is reading the sensors values and is giving decreasing influenz of the two MAPs the higher engine is reving.

In higher revs main influences on injection durations are fix given in table, corelated from values of TPS opening and RPM.
MAP values only have 10 percent influence there.
This is kind of damping in ECU

Think this is the way to go cause you are free to set necessary pulse damping even when pulses are hard and sensor to slow 🤔😉✋

Pure mechanical damping can be done by🤔

Length of hose
Its stiffnes
Its diameter

Avoid overheating sensor🤔

Take care about the fact, that temperature is changing stiffnes off diffrent hose materials ..maybe use metal tube in hot areas


GRÜßE Wolfgang

Nice thanks for the answer, i´ve bought maxxecu mini, it has an 3bar mapsensor built in.
I was thinking of using an fuelfilter(carburetor seethrough) with a restrictor on the 'intake side' that makes the air inside the filter to soften up the pulses that are going into the mapsensor.

[SwePatrick]

MAP, (Manifold Absolute Pressure) is a four stroke thing that has no equivalent in normal two stroke motorcycles. You cant put a MAP sensor on the inlet tract of a two stroke and have it work like it does on a four stroke.

Use Alpha-N (Throttle-Position / RPM) for every where you are on the pipe. But for trailing throttle into a corner, use VE (Volumetric Efficiency) for that and coming back onto the pipe as you exit the corner, MAP / VE.

For a two stroke, MAP can be approximated by the Difference between Max and Min crankcase pressure each cycle. This "Difference" varies with engine load and power output. More power or on the pipe, bigger difference than when throttling off, or trailing throttle.

Some Two Stroke EFI stuff:-

https://www.kiwibiker.co.nz/forums/s...50-EFI-Special

https://www.kiwibiker.co.nz/forums/s...2T-EFI-Project

Common MAP sensors put out their reading in one milli second bursts. This is what the MAP sensor reading the crankcase pressure on a 125 looks like. Purple line, Yellow line is the Ignition trigger.

1,800rpm 4,000rpm 10,000rpm

I used an Arduino Nano to find the Difference between the high and low reading each cycle and converted the Difference using a Digital to Analog card to get something that looks like a normal four strokes MAP value to feed into the EFI's CPU.



Alpha-N gets used everywhere that it is on the pipe, or definitely not on the pipe. I.E., us Alpha-N when the load is predictable. MAP and VE is used where the pipe is not sure if it is "On" or not.

If you are running Alcohol fuel I would not worry and just use the Alpha-N topology everywhere.

Nice info, yes my plan was alpha-n mapping.
And just have been told that you need to compensate for pipepressure when 'on the pipe'
I have always thought 'that seems unnecessary' as what i´m doing is dragracing and just having it wide open whole track
And as you write, alcohol makes it even more less sensitive to some 'bad mapping' where it could be a little bit rich(off pipe)

Rgds.

[Wos]

Nice thanks for the answer, i´ve bought maxxecu mini, it has an 3bar mapsensor built in.
I was thinking of using an fuelfilter(carburetor seethrough) with a restrictor on the 'intake side' that makes the air inside the filter to soften up the pulses that are going into the mapsensor.

For further Diskussion Patrick👍

I have used name MAP sensor for a sensor in mainfold in 4 stroke

Think its Important now to find best placement of sensor for your specific requirement... in your 2 stroke 👍😎✋

For myself I recogniced... there are realy better experts than me in special injection questions👍

OlFashionedCarbType in 2 strokes 🙈😉🤣

Wolfgang

[TZ350]

... my plan was alpha-n mapping ... as what i´m doing is dragracing and just having it wide open whole track ...

Yes, easy. Alpha-N, TPS vis RPM will be all you need for Drag Racing.

"MAP" manifold absolute pressure and "IAT" inlet air temperature sensors placed to measure outside atmosphere to compensate for changes in relative air density on the day.

[wobbly]

Hi Pursang , the issue with the " conventional " thermostat controlled system in a usual automotive situation is that they are only single acting.
As the restricted water flow heats up , it opens the plate valve and allows water to flow progressively more thru the radiator.

But in a 2T race situation it is all but impossible to have overcooling once the valve has fully opened.
On very cold days we can of course use tape over the rad to increase the engine operating temp , but when the optimum temp is under 45* this situation is rare.
In a double acting thermostat setup , the valve operates on both loops , closing one , as it opens the other , and can maintain the temp no matter how cold the ambient.

This is what I used to build 100s of for karts and race bikes, with the valve starting to work at 42 *C and was fully open at 45.

[SwePatrick]

Yes, easy. Alpha-N, TPS vis RPM will be all you need for Drag Racing.

"MAP" manifold absolute pressure and "IAT" inlet air temperature sensors placed to measure outside atmosphere to compensate for changes in relative air density on the day.

Yes, i was planning mounting the IAT sensor very close to the intake.
The MAP sensor is built in into the ECU, nice feature actually.

[Wos]

My fellow and i having a new project

Its a Puch Frigerio Gs 125 Enduro from 1980 for classic enduro sports in germany..

Its engine is a rotax 124 gs with rotary valve inlet.
RV is new for me to optimice and for enduro use, on this engine is a special long duct, to keep carb inside frame of the bike.

Surely long intake duct is a disadvantage in highend power 2 stroke??

But maybe good for torque in lower revs, that we want in enduro use?

Stock bikes with this rotax ( swm, kramer, kramit, puch frigerio) have torque like hell ��...but dont reve ��

Is somebody out, who can give first little help ...view...what we have to expect in case of this big air/ fuel mass between carb and RV...and which way is to go, to tune duct ( size like carb 34mm) by keeping its length...for first shot, tell you length about 200 mm... oh ��

Maybe a diameter change ? Or a nozzle inside could shift parameters to higher revs?

Try to add first photo..

But found more terrible things rotax in the 80ies did ! never seen tings like this head...exwindow...will show you next days fellows

Tanks!

Grüße Wolfgang

[Pursang]

But in a 2T race situation it is all but impossible to have overcooling once the valve has fully opened.
On very cold days we can of course use tape over the rad to increase the engine operating temp , but when the optimum temp is under 45* this situation is rare.
In a double acting thermostat setup , the valve operates on both loops , closing one , as it opens the other , and can maintain the temp no matter how cold the ambient.

This is what I used to build 100s of for karts and race bikes, with the valve starting to work at 42 *C and was fully open at 45.

Thanks for that, wobbly. Double acting thermostat changes things. So does your knowledge and experience!

[wobbly]

WOS , with a Rotary valve on a race engine it is all but impossible to mechanically make the intake too short.
Cut off that huge duct and make a pad on the cover to fit an off the shelf Mikuni oval carb rubber manifold.
This will get you real close , real quick.

[Wos]

WOS , with a Rotary valve on a race engine it is all but impossible to mechanically make the intake too short.
Cut off that huge duct and make a pad on the cover to fit an off the shelf Mikuni oval carb rubber manifold.
This will get you real close , real quick.

Pleasure for us reading from you wobbly !!

Will shorten as we can... but sideways carb is in enduro bad for carbs life in case of falling 😞 hitting sideways a tree...


In the Moment we are evaluating possible ways to go...

Soooo nice to have all the pros advice here! Wow!!

Will continue asking and learning for sure in case of special RV Questions...top !!


Thanks a lot



Grüße Wolfgang

[F5 Dave]

What odd things come out of the woodwork. Sadly you will need filtration and that horrible compromise will be an eye closed venture.

I remember riding a GP100 roadbike with knobblies downhill. There was a small log. A quick blip was called for. Quick flick of throttle .
Bleeer.
Thud over log. . . Braap.

Thought about it. RV had loaded up downhill and taken a while to clear.

Are you stuck with this engine?