ESE's works engine tuner

[TZ350]

All this talk of PWM solenoids, etc...

Makes me wonder if its possible to do away with the fixed aperture jets all together... run a standard carb setup but instead of a pilot and main run 2 x solenoids (one for each circuit) ... Essentially just a computer controlled jet size... Would it be a nice halfway measure between a carb and full on efi for a 2 stroke motorcycle?? Im not sure, just an idea.

Sounds very interesting ...

[husaberg]

Sounds very interesting ...

HRC, Cagiva, Bimota (admittedly direct injection for Bimota) and probably Yamaha spent big dollars (Ie millions) on fuel injection.
The results were a bike that made no more power and was harder to ride. Itohs NSR was faster, but he was tiny compared to Doohan and could tuck in better, also his best race results were on a Carburated bike.
Cagiva said the major benefit of doing it was to allow easy tuning to suit weather and the possibility of a more compact engine design later.
Honda said it would make no more power but had lower fuel consumption and that was their aim. To me an electric carb like a lot of 80s car had for emmisions was the worst of both deigns. just my biased thoughts on the mater. Carbs are cheap, relativity speaking, light and surprisingly efficient on a NA motor.
The biggest advantage i can see with fuel injection is for emissions with a direct injection system.

[2T Institute]

All this talk of PWM solenoids, etc...

Makes me wonder if its possible to do away with the fixed aperture jets all together... run a standard carb setup but instead of a pilot and main run 2 x solenoids (one for each circuit) operated by an ecu which varies PWM signals in response to a wideband input (or pre determined map of rpm vs tps vs temp, etc). Pilot solenoid reaches full duty cycle very early (same as a pilot jet), then main solenoid gradually increases in duty cycle (simulating the opening of the needle) until it also reaches max duty.

Itd be like a variation on the info 2T Institute posted about air correction circuits on RGVs/RSs etc

Essentially just a computer controlled jet size... Would it be a nice halfway measure between a carb and full on efi for a 2 stroke motorcycle?? Im not sure, just an idea.

RGV and RS is close to it, reality is it's there for emmissions not for performance. What your talking abouut is and electronic 'Master Tune' I could envisage this driven by a stepper motor. Zeeltronic is looking at a way of driving the stepper motor with their software.

[2T Institute]

Attachment 254814

Not quite flat and not quite 45 deg but getting there....

125cc Air cooled Rotary Valve with 24mm Carb, 1980 modified Suzuki GP125 commuter bike engine.

Plot your gearshift points on that and if that falls on the rising part of the torque curve only thing you have to do is buy some decent shocks

[husaberg]

Sounds very interesting ...

As interesting as this TZ

http://2stroker.createforumhosting.c...les-t3382.html

Armstrong worked with Gardner Carbs to develop a combined disk valve cover and flat slide carb assembly, to reduce inlet tract length. I believe there is a working example is in Germany

[Strokerhaus]

I would be interested to see the airflow results for the Gardners on a flow bench.
You may find they they flow better than a std style carb. Would you post a few pictures for the thread.
I had trouble finding decent pictures of then when i posted something about them.

Photo of Gardners 500 series on TZ attached ??? Possibly

Attachment 254848

[nasone32]

since you are talking about injection... i was reluctant to post here but i thought it might interest someone else...

i just bought an injection kit from ecotrons, i took the cheap way, we'll see if this thing works. It is a cheap construction kit, but the fuel pump and injectors look good and the included program seems made by someone intelligent.
http://imageshack.us/photo/my-images...12099copy.jpg/
http://imageshack.us/photo/my-images...12098copy.jpg/

i am going to mill my own throttle body after a quick test with the one they sell.

my only purpouse is to try the 24/7 valve idea by Frits. that valve has a huge transition in the jet size requirement, due to the air flow becoming very slow when the valve is opened (working in 24/7 mode), a carb can not cope with this kind of transition.
this very cheap efi kit has a real-time switchable map, that can be used to switch between closed and open valve mode...

(Also, if Mr Overmars is reading: If you are going to join the Continental Championship Race Tech in some way, and you would use a cvt, i would be very glad to sponsor, i have a belt cvt patent with a lot improved efficiency that i would like to show you... won the italian scooter champ this year so it's something already tested extensively)

[F5 Dave]

funny, I was thinking about the 24/7 idea last night as I drove home from the dyno having broken a reed.

Anyway it strikes me that if the concept did work (& the only time I've broken reeds the bike runs dreadfully up top), but either way to continue, if the bike did run ok 24/7 then surely the easiest way rather than this complicated reedblock arrangement; would be to make a round port into the back of the cases with the carb on it much like an RSA without the disc & a simple guillotine that closed it off (like a flat thin slide carb that went to the floor).

Then a 2nd pathetic size reedvalve with a 14mm carb with the same arrangement, but feed into the front of the cases out of the way. This could be used to start it, - then a Frankenstein lever pulled [bwahahahaha!] that opens guillotine 1 & closes 2.

[Yow Ling]

funny, I was thinking about the 24/7 idea last night as I drove home from the dyno having broken a reed.

Anyway it strikes me that if the concept did work (& the only time I've broken reeds the bike runs dreadfully up top), but either way to continue, if the bike did run ok 24/7 then surely the easiest way rather than this complicated reedblock arrangement; would be to make a round port into the back of the cases with the carb on it much like an RSA without the disc & a simple guillotine that closed it off (like a flat thin slide carb that went to the floor).

Then a 2nd pathetic size reedvalve with a 14mm carb with the same arrangement, but feed into the front of the cases out of the way. This could be used to start it, - then a Frankenstein lever pulled [bwahahahaha!] that opens guillotine 1 & closes 2.

Doesnt really sound complicated enough yet Dave, where are the stepper motors and sensors etc Is there an app we can download so we just run it from the phone.

Maybe 24/7 needs the perfect pipe to work properly

[F5 Dave]

yeah, also in my mind it was the monster pulling the lever, when it should have been Dr Frankenstein or Egor doing the honours. I don't know if this is important.

[TZ350]

yeah, also in my mind it was the monster pulling the lever, when it should have been Dr Frankenstein or Egor doing the honours. I don't know if this is important.

Attachment 254864

Who???? said we are doing what!!!! at team ESE, how did you know???

Attachment 254863

Still we will get the recipie right soon.

[TZ350]

Attachment 254903

OK ... been trying the after carb inline resonator but with an OKO carb, lost HP and was making 26 and less depending on the before carb resonator length.

Attachment 254873

On the bright side things went back to normall when I put the carb back in its conventional position.

Attachment 254872

30.40rwhp I picked up some midrange with a bit of jetting and ignition fiddling. I will have another play with the ignition and jetting tomorrow to see if I can pick up any more midrange, then its into making another pipe.

Attachment 254875

By a bit of clever machining Bucket managed to lose 15mm from the inlet tract length (it was 145mm). We will see how that goes tommorow night.

[wobbly]

That graph looks exactly like what you get by advancing the stator a bit.
More mid, less overev.
Can you now loose some timing past 12,000 to get the overev back.

[nasone32]

I noticed it is possible to simulate 24/7 with engmod2t, you just need to create a disk valve with 180 advance and 180 closing duration. 360° disk=24/7
Engmod is particularly efficient because it keeps a trace of every wave travelling here and there.

You can also play around a lot with crankcase volume, inlet lenght and diameter and see how much a 24/7 is sensitive to these params (an looks very sensitive of course). I played with exhaust pipes also, and looks like a conventional pipe works good, in fact the only way you could modify a pipe would be to thin the power range (and try to make more powerful pulses) but this way pays too much in term of usable range, with little or no gain at top...
also I think that with 24/7 you would like a very broad and long pulse to keep the air as much as possible into the engine, without coming back out from the intake.

[Frits Overmars]

...if Mr Overmars is reading: If you are going to join the Continental Championship Race Tech in some way, and you would use a cvt, i would be very glad to sponsor, i have a belt cvt patent with a lot improved efficiency that i would like to show you... won the italian scooter champ this year so it's something already tested extensively)

Hé Nasone, cosa stai facendo su questo forum?
A friend of mine, Martijn Stehouwer (twice european champion classic 50 cc racing in 2009 and 2010) is planning to build a 50 cc racer with CVT transmission for the CCRT series, so we are very interested in your belt. You can get in touch with him via info@emot.nl or via a private message in Pit-Lane.biz.

Regarding the exhaust pipe: the 24/7 system requires nothing out of the ordinary. A pipe that functions well on a 'normal' engine, will do just as well in combination with the 24/7-system, once it is running in the power band.
Like you said: the transition from reed induction to 24/7 may cause carburation problems, and the logical way out is fuel injection.