ESE's works engine tuner

[husaberg]

Stunning ... is this a first, never seen this way of tuning inlet resanance talked about in the go fast forums before.

Play it again TZ

That is a note worthy discovery

Its all about the Harmony. or is it Harmonics?

Interesting. Leonardo Da Vinci was a artist/inventor in the " resanance" as well.

Fittingly this is a link to the $2 Bell mouth.
Don't know if we still have Woolworth's department stores in NZ
http://autospeed.com/cms/A_110771/article.html

[NordieBoy]

Stunning ... is this a first, never seen this way of tuning inlet resanance talked about in the go fast forums before.

Only a problem when you need to use the clutch and cover the hole at the same time...

[kel]

Only a problem when you need to use the clutch and cover the hole at the same time...

Im concerned my hand might get trapped under the tank in tight left handers. Keeping in mind the curve is aimed at Kart track racing; we had it producing over 20hp but the fueling at 8k was appauling, damn thing wouldnt take anything like full throttle. The longer the inlet tract the less the problem, at 100mm length it would comfortably pull through with full throttle but fall on its face in the higher revs. After 56 pulls on the dyno TZ's not so secret inlet system was by far the best solution for spread of power. Seems ESE's talents arent just limited to 2 strokes, very impressed

[bucketracer]

Fittingly this is a link to the $2 Bell mouth.
Don't know if we still have Woolworth's department stores in NZ
http://autospeed.com/cms/A_110771/article.html

Bellmouth made froam an egg cup, good one.

[Grumph]

A rotary collar over the hole linked to an exup actuator motor....voila ! ....I give you the InUP Valve.

Actually, it's a bloody heimholtz resonator and you're tuning it by varying the inlet orifice size.

[dmcca]

Ok .... this is where the simulated rubber hits the road.

We are going to see if we can make this.

Attachment 253550

Red line is my efforts with EngMod2T, Blue line is after Wobbly polished it up a bit and replaced the RS pipe with one of his own design.

TZ, Im loving your build pics and posts... thanks...

Are you able to share any of the changes wobbly made to improve the power spread aside from the pipe... no need for specific numbers, just general concepts... particularly interested in the big ?improvement in low end. Are there any big ticket changes that led to the improvement over your initial design or just lots of small refinements adding up?

Cant wait to see the dyno results!!

[TZ350]

Wobbly has polished my original file, its his experiance that has made the difference, the adjustments to the each individual entry are small but they add up to a lot.

[TZ350]

... it's a heimholtz resonator and you're tuning it by varying the inlet orifice size.

That makes sense ...

It seems very effective, has it been done this way before? anyone seen any references.

[Moooools]

A rotary collar over the hole linked to an exup actuator motor....voila ! ....I give you the InUP Valve.

Actually, it's a bloody heimholtz resonator and you're tuning it by varying the inlet orifice size.

I would agree here.

The system you are using does not act in the same way as a musical instrument. Not at all. A musical interment uses standing waves, which have no velocity (or very very little. Now you tell me how waves with no velocity get into the engine.

In reality most of the air in the tube acts as a spring, and air at the opening acts as a mass. The mass of air oscillates on the end of the spring when the valve closes, and then when the valve opens the air is already traveling towards the inlet and it is easier to suck in.

By opening the hole all you are doing (in theory) is changing the volume of the 'air spring' that exists between the hole intake and the inlet valve.
While is appears to work I think that those are empirical results (they work just because). If it was working like you said and you covered half of the hole it would produce very nearly the same result. However if I am right it would have a significant effect on performance.

For repeatable results changing the length or diameter of the inlet is the only way to do it.

Oh but nice work getting some extra power out of the FXR. I am just a physics dickhead.

[bucketracer]

For repeatable results changing the length or diameter of the inlet is the only way to do it.

They may have done more than one run.

I suspect they did enough runs to satisfy themselves that it was a repeatable event and it only needs to be automated to be useful.

[Grumph]

That makes sense ...

It seems very effective, has it been done this way before? anyone seen any references.

The nearest thing to what you did is not the published heimholtz resonator stuff but I think the papers published by Annan? and Roe regarding side cavity resonances in SILENCERS....Internationally the silencing regs favour attenuating noise over certain frequencies and these papers related to tuning mufflers to the required frequencies using side cavities and different size orifices.

It would appear to me that the FXR had unfavourable wave activity at one rpm frequency - using the side orifice you made the inlet tract resonate at a different frequency which happened to make more power....The sheer size of the "bellmouth" has turned it into a resonant cavity which happens to be open to the air at one end.

[Moooools]

They may have done more than one run.

I suspect they did enough runs to satisfy themselves that it was a repeatable event and it only needs to be automated to be useful.

I mean repeatable in terms of you could two variables against each other and you would end up with nice curve.

I don't think that this method would produce a curve if you graphed length between hole and carb against increase in power at a given RPM.

[TZ350]

The system you are using does not act in the same way as a musical instrument. Not at all. A musical interment uses standing waves, which have no velocity (or very very little. Now you tell me how waves with no velocity get into the engine.

Yes I remember you explanation from before, and there sure was plenty of dynamic action with air blowing and sucking very strongly through the hole, so no standing waves there, like you say the action is something else.

Maybe I should have made it clearer that my comparison to the musical instruments this time was the action of uncovering the holes like a woodwind that changed the inlet tracts effect on the torque curve.

In reality most of the air in the tube acts as a spring, and air at the opening acts as a mass. The mass of air oscillates on the end of the spring

I think what’s happening is that the open hole destroys most of the spring effect reducing the springy bit of the inlet tract to the bit from the valve head to the first open hole and the bit from the open hole to the bell mouth becomes more flow than spring.

If this is true then there could be a series of holes at different distances from the valve which are progressively uncovered and in that way the torque curve could be held long and flat over an extended range.

Whatever the physics, it worked well on the dyno, we did in excess of 50 runs trying different inlet lengths etc and maybe 10 or so runs confirming the inlet tract hole results.

Thanks for your input.

[TZ350]

I don't think that this method would produce a curve if you graphed length between hole and carb against increase in power at a given RPM.

No, you wouldn't want to graph power thats the wrong result to look at, This is about cylinder filling and BMEP or torque.

Its the inlets effect on the torque curve thats important.

[Moooools]

Yes I remember you explanation from before, and there sure was plenty of dynamic action with air blowing and sucking very strongly through the hole, so no standing waves there, like you say the action is something else.

Maybe I should have made it clearer that my comparison to the musical instruments was the action of uncovering the holes like a woodwind that changed the inlet tracts effect on the torque curve.



I think what’s happening is that the open hole destroys most of the spring effect reducing the springy bit of the inlet tract to the bit from the valve head to the first open hole.

If this is true then there could be a series of holes at different distances from the valve which are progressively opened and in that way the torque curve could be held long and flat over an extended range.



Not sure by what you mean by "For Repeatable Results" do you mean this might not work tomorrow if we tried it again or that it may not be transportable to a different engine?

Thankyou for your input.

Repeatable as above.

Yes I would agree that that it is probably killing the resonance effect so it still works.

This discussion has me thinking about doing a tuned inlet myself, instead of just sitting here telling you that you are wrong.
Maybe when I clean up my bike next month I will have a crack at it. Then I just need to fork out some dosh for Dyno time.