ESE's works engine tuner

[wobbly]

I have a few customers on the pitlane threads, and for sure the 2T is alive and well in some classes still.
Im deep into the Rossi hydroplane motor as we speak.
And AMA has just changed a few classes "back" to enable the 2T to run again.

[kel]

I'm a bit worried some 30hp 2 stroke will just smoke us all at the GP, but we will have to wait and see.

team ESE seem very quiet

[husaberg]

I love 2 strokes especially the peaky, violent MX engine's of my youth. And my old gt50 of course the first bucket way back in 1987. I also like playing the villain 4 stroke guy. Gives you someone to focus all the energy towards. Lets see some action on the track. I'm a bit worried some 30hp 2 stroke will just smoke us all at the GP, but we will have to wait and see. Its great so many talented people are willing to share there expertise and knowledge. No that common in motor sport really. Especially the pinnacle class's of F4 and F5.

I share your views. besides someone has to be the devils advocate. The sharing of information we are seeing from Frits Jan and Wob along with others is unreal.
For years it was like some mysterious form of witchcraft. While the 2 stroke may at first appear to be a simple little device. There is so many variables that are all puzzlingly and at times frustratingly interrelated. So much more than I, ever would of imagined.

[Buckets4Me]

team ESE seem very quiet

I do belive that TZ350 has been in the states thats why there has been only a few posts by him and no work on his bike

wait till he gets back to it with all the new toys he will have brought back with him

I'm a bit worried some 30hp 2 stroke will just smoke us all at the GP, but we will have to wait and see. Its great so many talented people are willing to share there expertise and knowledge. No that common in motor sport really.

I'm afraid that all they guys with big H/P bikes up here are getting on a bit in years
some have been banned from riding there buckets

[gav]

http://youtu.be/5xKSbvHRLyU

Al Hoogie on his CBR150!

Results of the race here. A 1.54.8 lap time too

http://www.mylaps.com/results/showrun.jsp?id=2124606

[koba]

Click 'Show results by class' under the Motorcycling Canterbury logo to see who was in each class.

[husaberg]

For Fits you FOS engine.

Brillient idee



With the exhaust appearing to gain its time area with its formidable width instead of its height. Does that mean the effective duration of its power stroke is of a much longer percentage of the stroke (I hope this makes sense). Or is this cancelled out but it being positioned higher in the cylinder?
It may well be a silly question so apologies, if I missed that bit in translation.

[TZ350]

I have been trying to figure out if the bellmouth on the pumper does anything or not.



After a few dyno runs, apparently not.



28+ hp ... Blue with bellmouth, and Red without the bellmouth.



And the ignition curve.

An interesting thing, on overrun as its winding down on the dyno the bike will kick about if the ignition is too advanced in any particular spot.

By paying attention to when it kicks about on over run and the rpm I can get an idea where the ignition needs to be backed off.

[TZ350]

Next step was to try it with an Inlet Manifold.



Performance air filter inlet manifold from a VW car.



Now that lost a hp, Red line. And strangly required a richer H setting.

[wobbly]

The exhaust open point has very little to do with creating power due to "pressure" on the piston for "longer" with lower timings.
The gas pressures soon after TDC ,that creates the real power, is up over 80 bar, the pressure at Ex open is a couple of bar at best.
Moving from 200* to say 190* creates jack shit extra exertion of pressure on the piston to create torque, that then creates HP.
But the real issue is that down at 190* duration we get a huge amount of superposition of the gas pulse exiting the exhaust, on top of the residual pressure at the port.
This adding of a new pulse on top of an existing residual pressure means the wave front running down into the header has a huge relative amplitude, and this creates a huge depression at the port around BDC.
This also means we have port/pipe resonance over a much wider range and at a much high higher level than can be achieved at 200* duration.
In a conventional design we are forced into a corner by needing to create as much BlowDown STA as we can, and raising the timing is the only available route.
This pushes us away from the ideal port/pipe interaction timings, but is a compromise we are forced to accept to create the + 200psi bmep's needed, to be competitive.
Just another small detail that many overlook, or are unaware of.

[wobbly]

I am a little worried by the ignition curve.
Why is there 30* of base timing, then a "correction" of 15* to this.
If the base timing is correct, then no correction is needed at all.
It may not make any difference to what the engine actually sees, as a real timing, but what we see on the graph is rubbish.
The best way to establish a correct base timing is to use the straight line timing of say 30* btdc, over a wide rpm range, mark this on the rotor/stator, strobe it, and correct the base timing till
the actual 30* lines, line up in real time.

[TZ350]

The best way to establish a correct base timing is to use the straight line timing of say 30* btdc, over a wide rpm range, mark this on the rotor/stator, strobe it, and correct the base timing till
the actual 30* lines, line up in real time.

That’s exactly how we do it. Here is a video clip of Bucket using the dyno to check and adjust the base advance.

.I got the job of setting up NedKellys IgniTech programmable Ignition.

First step is to find TDC.

Mark TDC and the Advance you want, we chose 15 degrees BTDC. and marked them on the fly wheel, the flywheel turns ant-clock wise so the advance is marked to the left of the TDC mark.

This does not have to be that accurate as its only needed as guide so you can see that the ignition is firing somewhere near the right place. The ignition will be optimised on the dyno later.

The next move is to find the base advance.

Ours was about 10 Degrees.

The base advance is entered into one of those little box's in the program and initially the real advance is setup as a straight line in the curve part of the IgniTech program.

With the ignition programmed and the spark plug out, (but plugged into the HT lead and resting on the head) you can then use the Dyno's starter to spin the engine over. Then with the motor spinning over you can use a timing light to see if you have got the initial advance more or less where you want it.

If the advance lines don’t line up, you simply adjust the base advance setting and cylinder correction until they do.

With the initial advance setup more or less where you want it, you are ready to rock and roll on the dyno optimising the ignition curve.

The IgniTech software is very clever as changes to the ignition curve can be made on the fly and the Ignition itself re-programmed while the engine is still running............

Lots of pictures on Buckets original post.

Why is there 30* of base timing, then a "correction" of 15* to this.
If the base timing is correct, then no correction is needed at all.

Mine was the first one we set up and were not to sure what all the bits and bobs did, and how the correction and base advance interacted, it works so we have left it.

I think the initial problem was we needed more base advance than the 30 the Igni program allows. We may also have swapped the triggering from the heal of the rotor to the toe. It was a while ago so its all a bit hazy.

The programmable replaces a fixed ignition that ran best on this engine at 16 deg advance.

I am still not sure about the relationship between base advance and correction.

Is it.

Base Advance plus Correction, ie 30 + -15 = 15 deg Real Base Advance

or

Base Advance minus Correction, ie 30 - -15 = 45 deg Real Base Advance

[dmcca]

Aaaargh! I'm having big issues viewing this thread. I can look at anything else on KB but For several days now when I try to visit this thread I get an 'http500' error. Finally able to get on using my phone now but can't do it from either computer at home. Am I
alone?? Any suggestions.

TZ350 asked me to post the engmod2t questions in here for the benefit of others... I'll move it over as soon as i can log on via a computer.. It sucks trying to type on a phone!

[wobbly]

Not sure with your setup, as you should always be firing off the lobe trailing edge ( a dropping voltage) as rising edges are prone to read
spikes ( ie noise) as a control signal.
The procedure is to pick a known advance and mark this on the stator/rotor.Then change the base advance to get the lines coinciding.
Some use TDC and programme a straight line with 0* advance, its easyer to use the flat line in most curves between 2000 and 6000 that should be around 28* = 3.9mm in a 54 stroke.
Advancing the base, retards the firing point.
The correction factor is used for aligning the two channels of the ecu when firing both cdi off one trigger, as used in a Rotax tandem twin.
Due to pipe differences, they need up to 2* of retard on the rear cylinder in relation to the front one.
Your setup "works" but the graph bears no visual relationship to what the engine is actually seeing.
The CR250 race file attached is the advance the engine actually sees, as soon as you apply correction what you read, on screen isnt what you get.
The base advance firing of the lobe trailing edge is the timing seen at kickover ( up to 300rpm),then the map takes effect.
Thus its advisable to have a base advance that is in the range of 10 to 20* for easy starting, and then smooth idle.

[F5 Dave]

yeah I was going to say that's the queerest ign curve. was expecting to see scads more advance around 4thou if it were a road bike. might help you get out of the pits with less clutch slip.