ESE's works engine tuner

[Pursang]

If I can find a good way to indicate changes in air flow (charging efficiency) then I may be able to also use a Volumetric efficiency map below 25%, just like 4T's do.

I'm still of the opinion that, in simple terms, fuel delivery (and ignition management) determines the power output and that the necessary airflow will follow, unless restricted by throttling mechanisms.

But, if I was after an easy way to determine airflow through a 2 stroke, I would to use the expansion chamber restrictor as a pseudo (or actual) orifice plate. Differential pressure readings, plus a suitable correction factor, will give a good indication of the volumetric flow rate. Add temperature measurement for mass flow.

Cheers, Daryl.

[Muhr]

Both.

https://www.ronge-motorsport.de/

Thanks Frits!
That is definitely an option

This may be a really stupid question, but why can a 4 stroke run Ti Rods but not a 2 stroke? Is it because of the needle bearings? Ok, then why must we use a needle bearing? Is it because we can not get oil to the bearing with pre-mix if it is not a needle bearing? Sorry, asking for a friend

Do not know how common it is with TI conrods in 4stroke but 2 possible reasons are that they usually rev less and are often short stroke and of course crankcase lubrication

[SwePatrick]

Here:
Just place order

http://www.titanium-valve.com/pdf/en...onRod_Moto.pdf

[wobbly]

Foul strokes use Ti rods with bearing inserts and direct oil pressure feed.
They are capable of higher terminal piston speeds than a 2T due to this superior lubrication factor.
Look at the 250 MX bikes , they rev to the moon ( not only due to the short stroke ) usually then destroying everything in sight, but rarely the rod or bearings.
Ti rods have been made with thru hardened sleeves for the needles,but this is difficult to do reliably.

[TZ350]

I'm still of the opinion that, in simple terms, fuel delivery (and ignition management) determines the power output and that the necessary airflow will follow, unless restricted by throttling mechanisms.

A few experiences with holed pistons and overheating seizures from running lean/retarded or over advanced leaves me feeling cautious and happy to let someone else explore this concept.

But, if I was after an easy way to determine airflow through a 2 stroke, I would use the expansion chamber restriction as a pseudo (or actual) orifice plate. Differential pressure readings, plus a suitable correction factor, will give a good indication of the volumetric flow rate. Add temperature measurement for mass flow.

Cheers, Daryl.

Hi Daryl, "differential pressure" across the stinger restriction, that might have promise, if my current approach does not workout I will look at your differential pressure idea, could be good, thanks.

[Frits Overmars]

I would to use the expansion chamber restrictor as a pseudo (or actual) orifice plate. Differential pressure readings, plus a suitable correction factor, will give a good indication of the volumetric flow rate.

So if the pressure drops, you'll conclude that there is less air flow and you'll inject less fuel? Lean mixture = less power = less pressure = even leaner mixture...

[F5 Dave]

Chance to save weight on the rear brake?

[190mech]

Wax,
There is a good bit of info on ring pin relocation in this forum,Husa listed quite a few on this page;
https://www.kiwibiker.co.nz/forums/s...tuner/page1172

[Muhr]

No experience but

Almost forgot! thanks Husa

[Pursang]

So if the pressure drops, you'll conclude that there is less air flow and you'll inject less fuel? Lean mixture = less power = less pressure = even leaner mixture...

TZ wants an easy way to measure the instantaneous air flow through the engine....Not me, (it's a lagging indicator).

What he decides to do with the flow info is up to him.

Is the 'flow' is dropping because rider is closing throttle? (need less fuel, as above) or engine is losing revs as bike goes up a rise (need some more).

My suggestion is to tell the fuel system exactly what you are trying to achieve, (rate of deceleration, cruise or rate of acceleration) at any given combination of throttle position and RPM and inject the appropriate amount of fuel.

G-forces, the direction & rate of RPM change, or even braking pressure are relatively easy to measure.

To keep it simple for the rider, throttle position = power output (0-Max)

Might need to switch between multiple 3D FI maps or add more dimensions.

Cheers, Daryl.

[TZ350]

The head on the left has the standard NSR250 combustion chamber shape with its heavily shrouded plug and the other one has a sort of torodial combustion chamber and unmasked plug. To unmask it, the plug seat was faced back 2.5mm and I think a bath tub shape combustion chamber may be better. Both heads are viewed from the same angle.

There may be a place for modifying std NSR heads for ordinary road bikes by facing back the plug seat to unmask it and modify the chamber to a bath tub shape.

Unfortunately up until now, for the team bikes I had not been working to a standard cylinder length. Only taking a nominal 2.5mm of the top so some are 0.2 either way. Then the heads were machined to suit. Which makes the heads not immediately exchangeable between bikes for a back to back combustion chamber comparison on the dyno. Future cylinders after having a nominal 2.5mm skimmed off the top will be finished consistently at 83mm.

[Muhr]

Hello
I am working on another project where I am looking for a tunable ignition system and exhaust valve control unit. have looked at ignitech but have no experience with the valve control unit or its software. Is there anyone who has? Or someone who has experience of any other system?

[SwePatrick]

Hello
I am working on another project where I am looking for a tunable ignition system and exhaust valve control unit. have looked at ignitech but have no experience with the valve control unit or its software. Is there anyone who has? Or someone who has experience of any other system?

Just use an aftermarket ecu for fourstrokes,, cars.
It will have all the functions needed.

I ran DTA s6pro in a car, and it had fully configurable pid loops and more for it´s aux outputs.
And was capable of high revs.
Just delete the injectors, it will run anyway

[TZ350]

Hello
I am working on another project where I am looking for a tunable ignition system and exhaust valve control unit. have looked at ignitech but have no experience with the valve control unit or its software.

Totally recommend Ignitec. Team ESE use the DCP Race2 on our singles and find the PV easy to setup. If you get one I would be happy to help with answering questions on setup.

[wobbly]

The Ignitech PV servo and software is super easy to use.
The best way I have found to set it up, is to have two plugs in the wiring loom.
One is a two pin, just +/- power for the servo motor.
The second is a 3 wire with 5v ref,ground, and the pv position feedback.

You disconect the power feed, and simply rotate the servo to get full up, with no slack in the two cables.
This will show a mV reading on the screen for the up position.
Then rotate the servo for fully down, the mV is shown for that position on the screen.
So now all you have to do is input those values at the rpm you want, and you have a straight line ramp.
I always note the exact 1/2 up position of the valve in the port, especially if you have a two stage PV blade.

It seems that the servo will operate faster with no intermediate data points, but sometimes a straight line doesnt give the best power result.
So I then do 3 dyno runs with the valve fixed fully down, 1/2 way up , and fully up.
This gives you 3 best power rpm for those positions - adjust the rpm in the software to these 3 rpm and you are done.

As long as the +/- wire polarity is correct, the servo will cycle full up, then settle at full down, when powered up.
I dont like the PV software in the Race box, as it for some reason tries to zero any tiny offset reading when fully down, no matter what the hysteresis, and the motor will squeal
all the time with the correcting voltage being applied.