ESE's works engine tuner

[MotleyCrue]

Good to hear you are having success with your EFI system.

Yes, I found it relatively easy to get to full power runs but it is that part throttle, especially the full to closed then open again like you would throttling off for a corner that I am struggling with.

I found a lambda sensor did not help me much as the fuel lost with the inevitable short circuiting always made things look to rich when in fact they were not.

I think Wob has talked about putting the sensor at the stinger, I would like to know more about that.



True, sounds simple, well maybe, anyway it is pretty much what I have tried. I have had some success, but it is funny that the smallest part of the map. The area below 25% TP that I am having the most trouble with and it is this area that affects the rideability of the bike the most.

Attachment 320621

I had to do a little learning to get here but these are dyno runs from a map developed the way you suggested. With the various dyno runs in 10% steps from 100 down to 20%TP below that fueling was so bad the engine would not run well enough for any data to be recorded.

Now that I understand it a bit more I will follow your advice and take it to the track for practice on a Saturday. That way, if I stay out of everyone else's way I can play with the map and different sized primary injectors.

Another reason for calculating it all out carefully is that with staged injection you need predictable even steps between cells in every direction otherwise the ECU becomes confused when trying to swap between injectors.

Attachment 320622

The cross over in the 4,000 rpm area in the EngMod simulation is interesting too, I saw hints of this on the dyno but did not understand the reason for it until I saw the simulation.

If it was a dragster non of this low speed stuff would matter but a road race bike needs to be rideable under every condition. Including just trickling around the track to line up for the start.

Have you found anymore power with Ecotron or is this just an exercise to learn about FI ?

[wobbly]

I must admit I was very skeptical about using a lambda on a 2T, especially as several dyno operators told me they wouldnt use
the sniffer on a Dynojet ( even with its inline filters etc ) as it continually shit the probes.
But in 07 when we first went to USA racing the SKUSA CR125 box stock class,I saw a probe mounted thru an alloy bung welded
right at the front of a muffler.
The Lambda read the A/F going past inside the perf tube.
I asked to look at the data on the PI system, and there it was, a perfect readout varying with throttle and track position, between 12:1 and 15:1.
The fact it was 12.8:1 at full noise down the shute,told me it was saying the right things, as the egt was 1280*F, just as we were running - right on the edge.
The Yanks were obsessed with trying to get the fueling number correct the whole lap, and this made the corner exit ratio " correct " but slower.
And that jetting was too lean down low to get the kart launched at the starts as well.
So I ignore the numbers in this area and do all the bottom end response against the rear brake, on the stand.
If it will snap off the bottom when given instant full throttle from idle, then the pilot/needle/tube/slide are correct.
If it snaps from 1/2 throttle,without hesitation, or blowing a heap of rich smoke,then the mid jetting is correct.
We shot for a specific egt number in accordance with the weather, and this always corresponds with a A/F around 12.6 to 12.8.
So as we can use the egt ( but not Lambda ) in races I can then track the weather and jet change on egt alone.

[TZ350]

Have you found anymore power with Ecotron or is this just an exercise to learn about FI ?

No, not expecting to find any significant power advantage with EFI.



I needed to learn about fuel injection in a two stroke because my plenum idea suffered from enormous amounts of fuel drop out.

This both affected the fueling accuracy and left doubts about how much pre mix oil was making its way to the engine.

EFI is an attempt to get away from the fuel dropout problem in the plenum.

[dmcca]

I must admit I was very skeptical about using a lambda on a 2T, especially as several dyno operators told me they wouldnt use
the sniffer on a Dynojet ( even with its inline filters etc ) as it continually shit the probes.
But in 07 when we first went to USA racing the SKUSA CR125 box stock class,I saw a probe mounted thru an alloy bung welded
right at the front of a muffler.
The Lambda read the A/F going past inside the perf tube.
I asked to look at the data on the PI system, and there it was, a perfect readout varying with throttle and track position, between 12:1 and 15:1.
The fact it was 12.8:1 at full noise down the shute,told me it was saying the right things, as the egt was 1280*F, just as we were running - right on the edge.
The Yanks were obsessed with trying to get the fueling number correct the whole lap, and this made the corner exit ratio " correct " but slower.
And that jetting was too lean down low to get the kart launched at the starts as well.
So I ignore the numbers in this area and do all the bottom end response against the rear brake, on the stand.
If it will snap off the bottom when given instant full throttle from idle, then the pilot/needle/tube/slide are correct.
If it snaps from 1/2 throttle,without hesitation, or blowing a heap of rich smoke,then the mid jetting is correct.
We shot for a specific egt number in accordance with the weather, and this always corresponds with a A/F around 12.6 to 12.8.
So as we can use the egt ( but not Lambda ) in races I can then track the weather and jet change on egt alone.

This fits exactly with what ive found... I use a wideband o2 on the dyno and it is extremely reliable... made up a simple vacuum setup using a funnel held up against the main extraction fan for the room and it pulls exhaust gasses up through a 1/4 inch diameter copper tube thats pushed up the silencer. Reading are basically taken from the beginning of the silencer and drawn up past the sensor via rubber hose. The numbers are highly repeatable and after doing enough bikes you get to know exactly what AFR each bike likes at each rpm/throttle position. My dyno is an eddy current so i hold it at 4 or 5 rpm points and then test each point at 1/4, 1/2, 3/4 and full throttle... end up with a matrix of AFR's and its then very easy to make adjustments to pilot, needle or main to alter the AFRs at each point. Before using this setup i went through about 3 sensors a month ($$$ ), now i use 1 or 2 a year and the dyno is used 3-4 days per week. I also find 12.6-12.8 to be a good range to aim for up top, then slightly leaner around 13.5 at mid throttle and mid rpm, and leaner again around 14 at low throttle and low rpm.... this is for offroad and MX bikes though.

Im about to setup a KTM330 with an Ignijet so we'll see how this method goes with EFi....

[Flettner]

Where are you injecting?

[TZ350]

This fits exactly with what ive found... I use a wideband o2 on the dyno and it is extremely reliable... I find 12.6-12.8 to be a good range to aim for up top, then slightly leaner around 13.5 at mid throttle and mid rpm, and leaner again around 14 at low throttle and low rpm.

That is interesting because I saw similar numbers when I was playing with our wideband O2 sensor, I just did not understand them at the time, thanks.

[TZ350]

I want to see race 2 of this ....

https://www.youtube.com/watch?v=HcK1As59jkI

The great sound of a two stroke Bucket, real music.

GP Boneshaker...

https://youtu.be/8EwKlNBTgsc

Tokoroa GP

[dmcca]

Where are you injecting?

Similar to your YZ setup with one injector into each B transfer duct just inside the port window. Will be coming in from the rear of the cylinder rather than downwards like yours... Simply due to clearance issues. Using an electronic fuel pressure regulator and a dead head system, so no return to the tank and it should cut power consumption down... Pump is only fed enough power to maintain pre-set fuel pressure.



Sent from my iPhone using Tapatalk

[adegnes]

Checked the balance factor of the Spx crank today.
Without any added weight to the small end it's heavier on the crank pin side.
Small end = 27g
Reciprocating mass = 109g
27/109 = 0.25.

Balance factor < 25%.
Explains the shakes i suppose.

[Frits Overmars]

Checked the balance factor of the Spx crank today. Without any added weight to the small end it's heavier on the crank pin side.
Small end = 27g
Reciprocating mass = 109g
27/109 = 0.25.
Balance factor < 25%.
Explains the shakes i suppose.

It may explain the shakes but it doesn't explain how you arrived at that balance factor - not to me anyway. Would you care to show your calculation step by step?

[AndreasL]

You lost me during your calcs adegnes...
There have to be some numbers missing here, doesn't it?

[adegnes]

It may explain the shakes but it doesn't explain how you arrived at that balance factor - not to me anyway. Would you care to show your calculation step by step?

I used TZ's instructions from here, was there something I didn't get right?
My conclusion is hat the balance factor is less than 25%, not exactly 25%, if that was misleading.

.

Re-Engineering to find the Balance Factor of a CrankShaft.


Pic-1 Hang things of the little end untill.............

Pic-2 ...........the crank no longer rolls and stays in whatever position it's placed.

Pic-3 Weigh the washers and the little end.

Pic-4 Weigh the Reciprocating Mass.

Divide the Weight of the Washers + weight of the Little End by the Weight of the Reciprocating Mass and there you have the Balance Factor.

Rearanging the formula I posted earlier.


Let:- "Washers"+"Little end" = A "Reciprocating Mass" = B and "Balance Factor" = C

Then Balance Factor C = A/B .............."Weight of the Washers"+"Weight of Little End"/"Weight of the Reciprocating Mass"




.

[AndreasL]

adegnes, when adding mass to the little end (to make it "stay in any crank position") you will get a higher balance factor %, not a lower one.

So the linked explanation is correct, but I think you have misinterpreted it a bit.

[Frits Overmars]

I used TZ's instructions from here, was there something I didn't get right?
My conclusion is hat the balance factor is less than 25%, not exactly 25%, if that was misleading.

I can't find anything wrong with your conclusion. Sounds like you will need a couple of heavy metal slugs - or an angle grinder.
Still makes me wonder: who on earth built the crankshaft like that?

[AndreasL]

.

The KISS method of balancing a single cylinder 2 or 4-stroke.

Its all in the pictures:-

Pic-1 Find the total reciprocating Weight (Mass)
Pic-2 Find the Little Ends reciprocating Weight (Mass)
Pic-3 Find the Balance Facter (Ie. 65% is 0.65 X the ToTal Reciprocating Weight (Mass))
Pic-4 Leave the Little Ends reciprocating Weight (Mass) on the Scales
Pic-5 Attach the rest to the crank.
Pic-6 Balance the Crank.

From Phill Irving. page 109 "the wheels will roll freely along the straight-edges and show no tendency to settle in any one position; if not, the pin will go to the top or bottom according to whether the Counter Balance is to heavy or to light. Correction is usually made by drilling the rims."

Very simple, very effective, a very accurate way to balance a single cylinder crankshaft staticaly. If anyone can come up with a better static balancing method, Thomas and I would like to hear about it.

To find the existing balance factor of a crank shaft, you just more or less work through this process backwards.

.

A summery of TZ's method.