ESE's works engine tuner

[andreas]

Trial&error attempt YZ 85.
Production continues slowly, and revised with thicker gauge sheet for better durability and aestetics.

[diesel pig]

You have a point, but it depends on how you define bottom end power. For me it's the initial part of the power band, and if you are anywhere in the power band, the 24/7 reed should already be swung out of the way, so it won't matter how hard or soft it is.
Below the power band a soft reed would have benefits, as you say, but it will never be enough to justify running below the power band.

I must admit I was really just thinking out loud. I was wondering with that question about the reeds, if the 24/7 system had a really strong bottom end power curve that might help the 24/7 system as it came into the start of the main power band curve. I think just like the ones who came up with the ideas for things like performance exhaust pipes and multiple transfer ports, they knew these things, it would increase performance but didn't know at the start of their ideas by how much power it would add or what the power curves would look like until they built them and tested them. The more I find out about the 24/7 system the more interested I am in it. Thank you for telling us about it.

[TZ350]

Supercharged 50cc Two Stroke Turbine Flutter & Flamethrower!

[dutchpower]

Trial&error attempt 1. YZ 85.

What year yz 85 Andreas

[andreas]

It's a 2023.

[andreas]

I was randomly strolling around the pages, when I set foot at p1500 onwards, alot of interesting stuff going on here, the 2-1 pipes and Wobblys exhausteside piston cutaway seadoo. Can't even imagine how that idea came to being an how erratic the induction would have been. Maybe it will work also on a regular engine, but using the 2nd reflections depression wave when it reaches the face of the piston at TDC?
Also I see at various places Frits mentioning the Helmholtz effect on the tuned pipe, but haven't seen how it actually work. and to what extent. Maybe you can do a nice lecture on this subject?

[Frits Overmars]

.... I see at various places Frits mentioning the Helmholtz effect on the tuned pipe, but haven't seen how it actually work. and to what extent. Maybe you can do a nice lecture on this subject?

I did, some time ago, on another forum. Unfortunately I can't find the English version, but maybe the original German version will be of some use to you.
To be taken with Aspirin .

[andreas]

Thanks Frits. I'll do my best with the translation.

[Frank S.]

Hi,
here is a write up about the intake helmholtz resonance.
Frits called it the Helmholtz-blues

http://www.pit-lane.biz/t117p740-gp1...-part-1-locked

[andreas]

Frank, yes I've read the Helmholtz Blues.

[lodgernz]

I did, some time ago, on another forum. Unfortunately I can't find the English version, but maybe the original German version will be of some use to you.
To be taken with Aspirin .

hier ist die englische version:

[andreas]

hier ist die englische version:

Vielen Dank

[wobbly]

The piston cutaway idea came from staring at Dynamation pressure wave screens for hours with a 2 into 1 being modelled.
It only worked with in excess of 200* Ex duration and at the time I thought how impossible it would have been to tune if not using a pumper carb setup.
They function almost like fuel injection in that a throttle body size that is way too big to be tuned correctly if a carb was used , due to the low velocity at low rpm/WOT , giving low depression values ,make jetting impossible.
The pumper can be made to change the fuel curve dramatically at any rpm/throttle position using the pop off pressure , lever height , with dual fixed and screw adjustable pilot and main systems.
They are unique also in that the idle/pilot progression holes arrayed in front of the butterfly as it opens , also actively function as main air correctors at WOT - thus enabling all manner of tuning anomalies to be
overcome.

[dutchpower]

Trial&error attempt 1. YZ 85.

Andreas test it like this save you lot of work you can make changes quicker

[andreas]

Very interesting Wobbly. Yes pumper carbs are mostly out of my scope.