ESE's works engine tuner

[Moooools]

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.

What he said.

Except that at a given rpm power is just a multiple of torque.

[TZ350]

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

Yes certainly, the dyno tells use something usefull is happining.

I wanted to try a very long inlet with several holes but we ran out of time. I guess the ideal would be to try several different length bellmouths then a long one with holes the same length as the bellmouths and compair the results.

I am looking forward to hearing about your own experiments.

[TZ350]

Except that at a given rpm power is just a multiple of torque.

True, maybe your right, as there are three variables, rpm, inlet length to the first hole and torque.



What really surprised me was the inlet with the hole closed was crap up top but with the hole open it had the tuned length (to the hole) of the carb but made better power up top than the carb did. I would have thought the plumbing of the long inlet would have been more restrictive to air flow than the naked carb and made less power.

[Moooools]

True,



Maybe your right, there is three variables, rpm, inlet length to the first hole and torque. Idealy you want to maintain a flat (but high) torque curve throughout the rpm range.

Well with on three axis of course.

I can't quite think but maybe something like this.

http://www.livephysics.com/ptools/on...%2F4%29%29-2*y

[Yow Ling]

Well with on three axis of course.

I can't quite think but maybe something like this.

http://www.livephysics.com/ptools/on...%2F4%29%29-2*y

Ahh the Brainy asian girls site, must do more homework

[Yow Ling]

Really interesting stuff with the flute inlet, is this just a simple way of varaible trumpet length like on the Norton/Roton rotaries.

I have modified a RZ350 PV controller so it opens at different rpms etc and opens different angles, yamaha used the same controller for everything rz250/350, tdr250, Vmax, exup, you just change the jumpers or put some dipswitches where the jumpers were, cheaper than getting the all singing Ignitech for something like this . just needs a ignition signal.

Does the engine note change when you cover the hole?

[TZ350]

... is this just a simple way of varaible trumpet length like on the Norton/Roton rotaries ... Does the engine note change when you cover the hole?

I am expecting that with several holes you could get a step wise result that mimics the Norton rotaries, next time that FZR is on the dyno I will try to do some more tests.

The engine note in the 6-8K rpm range changed from running roughly to running well.

I would like to know more about the RZ servo controlers.

[kel]

Im certainly no expert on these things but I think in part the longer inlet was cancelling the negative effect of the Mega phone exhaust at 8k, opening the inlet hole at 8.5k seemed to shorten the inlet tuned length and allow the mega phone to do its work within its range. When I removed the mega phone from the Lesoft engine model it immediately picked up 2 hp at 8k just as we saw with TZ's inlet, but then it also lost the hump in the 9 to 11k range.
Hopefully Frits might explain what we were seeing (I know 4 strokes arent your thing Frits, perhaps you could consider it purely for the physics)

[Yow Ling]

http://tzr250.com/forums/index.php/t...53.30.html:the

[TerraRoot]

the MV F4 has a variable intake, but instead of a hole (which mustn't flow very well) an extra length of trumpet is lowered on to the set trumpet, works quite well i think.
http://www.sportrider.com/news/146_0.../photo_02.html

[TZ350]

I was expecting the hole to flow worse to (blue line), ie less power but it made more power on the dyno than the std carb (red line) it was being compaired too.

the MV F4 has a variable intake, but instead of a hole (which mustn't flow very well) an extra length of trumpet is lowered on to the set trumpet, works quite well i think.



http://www.sportrider.com/news/146_0.../photo_02.html

1980's Nortan Rotary racer with variable inlet.



Norton Rotary at the TT



A quick trot around the Island.



And this is how fast they were in their day ....

[NordieBoy]

What really surprised me was the inlet with the hole closed was crap up top but with the hole open it had the tuned length (to the hole) of the carb but made better power up top than the carb did. I would have thought the plumbing of the long inlet would have been more restrictive to air flow than the naked carb and made less power.

Maybe what you want is an inlet with a longer slot the width of the hole and a moveable sleeve with the hole. Then you can move the hole toward either end of the intake?

[TerraRoot]

i think the hole does flow worse then if the bell mouth was the correct length.
longer intakes move the torque down lower in the rev range but if its sooo long (like it is) the cams profile is probably working against it and bingo big hole in the rev range.

[teriks]

That would be around double the surface area though?

Ever seen Tiger Woods pause play because of overheated balls?

Well, maybe not golf balls...



Daily News 2010: "Tiger Woods is being treated for sex addiction at a posh clinic" "He's not going to be allowed to go out and golf in the morning,"


Re. the dimpling, I'm simply questioning the return on invested time.

[wobbly]

Just a small reply re the Pulse bike that Bill has in his lounge - the chassis geometry was designed by Mike Sinclair and built by
the Roberts factory in Milton Keynes.
I have a bare one here in my workshop, that I am looking to stick a 400F3 engine into ( nothing better to do - you know how it is ).

I love the side resonant ( thats what Prof Blair calls that setup in his books ) "flute" idea - I understand that several new super-bikes have variable trumpet length that is actuated by rotating the outer trumpet sleeve.
This is fixed to the inner on a peg, with a spiral slot on the inside of the outer.As it rotates, it lengthens the trumpet on this long pitched screw slot.
You could use the same idea by uncovering staggered holes as the outer rotates, without changing the length.