ESE's works engine tuner

[husaberg]

Ha ha love it.

Nice site with nice bit on Mr Jan Thiel
http://www.classic50racingclub.co.uk/jamathi.html

[TZ350]

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Simplified drawing of the pressure cycle in a two stroke crankcase. The low pressure is typically at TDC and the Maximum pressure is typically 140 deg ATDC this is much the same for all typical two strokes. The average pressure is high, about 0.8 bar at WOT and near 1 bar at idle.

The difference in height between the maximum and minimum pressures changes with air flow, more air, the bigger the difference.

The plan is to use this difference to see the changes when the engine is on the pipe or not.

The changes are subtle enough to be used as a MAP value in the traditional 4S sense.

[Flettner]

Probably what KTM are doing.

[Frits Overmars]

Nice site with nice bit on Mr Jan Thiel
http://www.classic50racingclub.co.uk/jamathi.html

Not the best article on Jan Thiel I've ever read. I won't go into all of it; I'll leave that to Jan if he thinks it's worth it. Just one detail: Jan was born on 3 June 1940.

[husaberg]

Not the best article on Jan Thiel I've ever read. I won't go into all of it; I'll leave that to Jan if he thinks it's worth it. Just one detail: Jan was born on 3 June 1940.

I haven't read it yet, I only found it looking for pics of RC115 brakes.

[F5 Dave]

Axially mounted? How old fashioned!

[JanBros]

Axially mounted? How old fashioned!

look good, they are radial and were ahead of their time

[jonny quest]

.

Simplified drawing of the pressure cycle in a two stroke crankcase. The low pressure is typically at TDC and the Maximum pressure is typically 140 deg ATDC this is much the same for all typical two strokes. The average pressure is high, about 0.8 bar at WOT and near 1 bar at idle.

The difference in height between the maximum and minimum pressures changes with air flow, more air, the bigger the difference.

The plan is to use this difference to see the changes when the engine is on the pipe or not.

The changes are subtle enough to be used as a MAP value in the traditional 4S sense.

So the pipe is pulling .2bar out of crankcase

[F5 Dave]

look good, they are radial and were ahead of their time

Ahh crap I got hung up seeing a mount on one side and my head said if they were on either side they would be radial but of course they are.
Kinda spoiled the joke now.

[husaberg]

Ahh crap I got hung up seeing a mount on one side and my head said if they were on either side they would be radial but of course they are.
Kinda spoiled the joke now.

If it makes you feel better the tires are cross ply.

[TZ350]

So the pipe is pulling .2bar out of crankcase

It looks complicated, a lot of the lowest crankcase pressure is after the inlet has opened, the exhaust port has closed and TDC so the rising piston is playing a part too.

[Frits Overmars]

The lowest crankcase pressure is around TDC so the rising piston must be playing a part too.

This way of reasoning could block your brain, TeeZee. The part played by the piston is quite weak compared to what the Helmholtz resonance is capable of.
For example, at low revs you can experience blowback while the piston is still rising, just because the Helmholtz frequency is too high for the inlet angle/rpm combination.

[TZ350]

This way of reasoning could block your brain, TeeZee. The part played by the piston is quite weak compared to what the Helmholtz resonance is capable of.
For example, at low revs you can experience blowback while the piston is still rising, just because the Helmholtz frequency is too high for the inlet angle/rpm combination.

Yep, it's a complicated dance.

[husaberg]

.

Simplified drawing of the pressure cycle in a two stroke crankcase. The low pressure is typically at TDC and the Maximum pressure is typically 140 deg ATDC this is much the same for all typical two strokes. The average pressure is high, about 0.8 bar at WOT and near 1 bar at idle.

The difference in height between the maximum and minimum pressures changes with air flow, more air, the bigger the difference.

The plan is to use this difference to see the changes when the engine is on the pipe or not.

The changes are subtle enough to be used as a MAP value in the traditional 4S sense.

Isnt it more important to see the difference between deceleration and acceleration.
I say this as isn't the issue with fueling related to over run performance vs acceleration fuel mapping?

[crbbt]

whom as seen this?