Speeduino 2T EFI Project

[TZ350]

My thoughts are to map all the variables with a carb on (as we know that maps create and responds to the variables)measuring fuel flow plus all the different pressure readings then create a truth table.

Yes that is a good idea, do you or a friend have a 2S with a carb you could do this mapping with. I would be very interested in the data.

[husaberg]

Yes that is a good idea, do you or a friend have a 2S with a carb you could do this mapping with. I would be very interested in the data.

As I am operating with one arm plus a fractured back atm so unlikely i could even start the CR500, plus i am a complete Bastard so i have no friends anyway.
Plus i like carbs, i almost understand them

[TZ350]

.
Sorry to hear you have been hurt.

Your data mapping looks like a good plan. As you cant help at the moment it will have to be plan "B" so it can wait a bit. The plan "A" is to get the bike running as well on the new Speeduino system as it did with the old Ecotrons CPU. Then see if blending AN and VE in the troublesome areas does anything worth while.

Other wise I will need to turn to you for that plan "B" data. Get busy and make some friends......

[husaberg]

.
Sorry to hear you have been hurt.

Your data mapping looks like a good plan. As you cant help at the moment it will have to be plan "B" so it can wait a bit. The plan "A" is to get the bike running as well on the new Speeduino system as it did with the old Ecotrons CPU. Then see if blending AN and VE in the troublesome areas does anything worth while.

Other wise I will need to turn to you for that plan "B" data. Get busy and make some friends......

I think you need to use a disc valve test mule as well as they would be different than a reed.
I think mapping all the pressure data is easily doable, but the fuel flow in real time would be bloody hard , maybe with a single circuit carb like a lake injector but i have no idea how to measure fuel flow in real time accurately is fast enough?
Why not approach link as far as i can see you would need a transducer pre and post disc plus on in the pipe?

[TZ350]

I think you need to use a disc valve test mule as well as they would be different than a reed. I think mapping all the pressure data is easily doable.

I have the disk valve test mule. When you have perfected the data collection system using your reed valve bike I would love to borrow the test gear and run it on my disk valver.

[TZ350]

There is a newer hot wire like system that uses a plastic film protected on one side.

It sounds interesting. Do you have anymore info? ie what uses them and is there an inexpensive source. What cars should I be looking at in the wrecker yard.

[Drew]

Surely with the injection and a disk valve, fuel cant end up splashing back past the throttle body?

[husaberg]

Surely with the injection and a disk valve, fuel cant end up splashing back past the throttle body?

Google three times the mainjet

[TZ350]

Well that was an interesting afternoon. Tried smaller injectors to try and get the VE numbers up for better resolution but after a lot of work all I had to show for it was confirmation that I had the right ones to start with.

Well, bummer, and sorry if I sent you barking up a tree, but it actually tells me more than that. You either (or all four) have greater power output, or poor latency, or actual Lambda richer than expected, or blowing more out the pipe than expected. The up-side is down the road, where more efficiency and/or power is potentially hiding; though it didn't need this exercise to find it. :? Where did you end-up for config numbers? David

It was probably worth the effort to confirm the injector sizing. Actual Lambda needs to be around 12.5:1 for a 2S. Maybe that is to cope with the residual exhaust gasses left in the cylinder. Gives an oxygen a better chance of finding a fuel molecule. For config numbers, I am not sure. I finished up chasing my tail for a bit and basically have to start again.

VE is a good concept for 4T's but misleading for a 2T. For 2T's it is all about "Transfer Ratio" and "Trapping Efficiency".

My bike may have a true VE of 80% (of 110cc) but the "Transfer Ratio" of air transferred to the cylinder is maybe 120% and the "Trapping Efficiency" of the air actually trapped in the cylinder after the exhaust port closes is maybe 66% of that 120%. So there is a wasted 34% of air that also gets fuel in it but is not burnt to produce power. The better I can time the injection so less of that 34% of wasted air gets fuel in it the cleaner the emissions and the better the fuel economy but it will never be perfect.

A Carburetor adds fuel to all the air that passes through it. Whether the air is being sucked in by the engine or blown back out. Either way it gets fuel added to it. Properly timed EFI can do better than that by avoiding adding fuel to air that is being blown back out of the crankcase. So EFI can effectively reduce pollution at the inlet and exhaust sides of the engine which would improve fuel efficiency too.

I think the bigger than expected injectors are needed to cover that 34% of wasted air that passes through the engine and the richer air/fuel requirements of a two stroke.

Picture of the bike on the dyno and a picture of the last dyno graph using the Ecotrons CPU. The plan is to get back to the same level then take a look at using the Speedy to find ways of seeing the changes in air flow through the motor that are induced by changes in the resonant action going on in the pipe. Ie, we want to be able to see the air flow changes when we throttle off and on again. The Ecotrons Alpha-N methodology could not do that but I am hoping that by adding a MAP value to the mix better drivability will be possible.

1st step is to get back to where I was before swapping CPU's.

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[TZ350]

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Surely with the injection and a disk valve, fuel cant end up splashing back past the throttle body?

Google three times the mainjet

..... https://www.kiwibiker.co.nz/forums/s...-tuner/page367

With a carburetor fuel is added whether the air is going in or coming out. 2S EFI "B" port injection can mostly avoid adding fuel to air that is being ejected from the crankcase.

[husaberg]

It sounds interesting. Do you have anymore info? ie what uses them and is there an inexpensive source. What cars should I be looking at in the wrecker yard.

It was new to me as well
Bosche do them pretty much exclusively now so likely mini VW and BMW

The Bosche system auto heats the hot wire to 1000 degees on shutdown or start up to burn of residue too.


all these ones here with HFM
https://www.turnermotorsport.com/c-2...ss-sensors-hfm
at the bottom is the years and models

or Beemer
for E46 M3, E60 M5, E63 M6, MZ3-S54, MZ4

2001-2006 E46 BMW M3
2006-2010 E60 BMW M5
2006+ E63 BMW M6
2001-2002 Z3 BMW M Roadster M Coupe with S54 engine
2003-2008 Z4 BMW Z4 M Roadster Z4 M Coupe
$189.95 this one is compact

E39 M5, Z8

ie 1999-2003 E39 BMW M5
2000-2003 E52 BMW Z8 Roadster
$139 new

https://www.turnermotorsport.com/p-3...6-mz3-s54-mz4/

oh look the sensor itself is dirt cheap
$32.41
https://www.turnermotorsport.com/p-2...uine-bmw-part/

Its also a mint DRZ125 engine.

Paging former Beemer witch doctor.....

unconfirmed but i think the 3.8 buick v6 commodores had a film maf sensor..........

The hot film MAFs, which AC Delco introduced in '84 on the Buick turbo V6 and have since used on the 2.8, 3.0 and 3.8L V6 engines, produce a square wave variable frequency output. The frequency range varies from 30 to 150 Hz, with 30 Hz being average for idle and 150 Hz for wide open throttle.

Nah buggar the holden one didnt use maf until the VS and even then i am not sure if its hot film them.


here is a pic of the output of the GM system used in the states

On the GM hot film MAFs, you can also tap into the onboard computer data stream with a scan tool to read the MAF sensor output in "grams per second" (GPS). The reading might go from 3 to 5 GPS at idle up to 100 to 240 GPS at wide open throttle and 5000 RPM.

https://www.aa1car.com/library/maf_sensors.htm

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on another subject i found this which i never knew about Map sensors

Waveform notes

The Manifold Absolute Pressure (MAP) sensor waveform seen in the above illustration is a typical output from an analogue sensor. With the motorcycle's engine at idle, the voltage shown on the example waveform is at 1.0 volts. The throttle is then snapped open and the voltage rises to just under 5.0 volts. The voltage achieved depends on how fast the throttle is opened, as a slower reaction time results in a lower voltage. While the engine is slowing back to idle with the throttle closed, the increased vacuum within the inlet manifold results in a lower voltage than that seen at idle. This lower voltage returns to the original voltage when the speed returns to idle.



Technical information

MAP sensors can be either integral to the motorcycle's ECM or separate units. An ECM that is fitted with an internal MAP sensor can be identified by a vacuum pipe connection.
External MAP sensors are three wire devices which have:

• a 5 volt supply voltage
• an earth connection
• a varying analogue output
• a vacuum connection to the inlet manifold

The output from the sensor shows a rise and fall in voltage depending on the vacuum.
When the engine is stationary or the throttle is wide open, zero vacuum will be recorded and a voltage approaching 5 volts will be seen; as a vacuum is applied the voltage will reduce. The example waveform shows that at idle a voltage of around 1 volt is seen, and as the throttle is opened the vacuum in the manifold drops and a higher voltage for these conditions is seen. In this case the voltage rises to almost 5 volts.
The 'hash' on the waveform is due to the vacuum change from the induction pulses as the engine is running.

mabye this is the way to make it work with alpha N?
treated like a turbo car one map and Maf either side of throttle as to detect boost which would be vacuum in a two 2t you might need one on the pipe though as well.

[Drew]

My bike may have a true VE of 80% (of 110cc) but the "Transfer Ratio" of air transferred to the cylinder is maybe 120% and the "Trapping Efficiency" of the air actually trapped in the cylinder after the exhaust port closes is maybe 66% of that 120%. So there is a wasted 34% of air that also gets fuel in it but is not burnt to produce power. The better I can time the injection so less of that 34% of wasted air gets fuel in it the cleaner the emissions and the better the fuel economy but it will never be perfect.


.

Best written description I have ever read on this subject, I understood all of it and could picture it without going backwards and forward a dozen times.

[husaberg]

if iis hot film
its cheap
https://www.ebay.com.au/itm/MAF-Air-...-/162637109813

[ceci]

with which we are neighbors, the government of my country in those years impeded the importation of this jewel

https://www.motobecane-passion.fr/in...ectronique.htm

[ceci]

with which we are neighbors, the government of my country in those years impeded the importation of this jewel

https://www.motobecane-passion.fr/in...ectronique.htm

It is good to look to the past to see everything that has been advanced