ESE's works engine tuner

[Sketchy_Racer]

Just so people get a handle on the reality of my situation re the F3 bikes.
One customer whos engine had done over 50 full noise dyno tests, took the bike to Taupo.
There it did 4 - 20 minute sessions as hard as it would go, bad front end issues, no brakes, and wrong gearing.
Max egt 1235 with 195/198 mains.
Pull the barrel and the pistons look like new - see the pic..
Now it has done another full day at Manfield with super rich jetting to try and nail the handling.No problems, needs attention at trailing part throttle, mid corner.
But in a straight line you " hang on for grim death ".

The other customer ran the bike for the first time with the same jetting, at sea level, after being told to go up to at least 210, and not exceed 1250 - the red lights ( 4 of them ) come on at 1260.
He didnt, do as advised.
First fast session it hit 1350 with all the lights flashing like crazy.
Carried on for 5 more laps till it siezed on part throttle.
I have never in 30 years seen an engine survive over 1300 F, ever.
Piston to bore is now over twice what it should be - surprise , surprise.
Now im told Wossner pistons are shit - the plating is shit - and by inference I couldnt tune my way out of a brown paper bag.
Am I angry - yes.
Easy to fix - yes.

Might need to put in a anti retard cutout when EGT's go to high, what a pillock.

When are we going to see someone pilot one of these in F3. The Ozzy450 I rode in 2008 was awesome fun and set lap records at manfeild and puke but I'd say the power vs weight of your weapons would be a serious contender.

[Flettner]

I see the EFI CR500 featured in Dirt Rider Downunder is sporting a carburetor now. What happened?
I thought we were looking at the future.

[husaberg]

Seems the only info HGT gives out is "...........for 31yrs I was a GM engineer..........."

BRC (make Rotax 256 copy kart engines) Riley Will (who contributed to the pitlane.biz RSA thread) spoke the most sense there

The 2002 500cc bikes used 35-36mm carbs with electronic solenoid type power jets.

KTM used a hybrid system where they used an injector to augment the fueling requirements. It was used in their 250cc program, but I'm not 100% sure if they used it in the 125cc bike as well. Probably, but I cannot be certain.

Aprilia was guilty of throwing out what they perfected (carburation)and introducing a totally new concept loaded with technology EFI system. It was an intelligent system that made all the theoretical calculations at light speed..... It was a perfect system....... Too perfect! For years 2 stroke engine development was being done using less than perfect carburetor. This includes rider knowledge, tire construction, and suspension..... The end result was that the riders and machinery (tires) couldn't cope with the instantaneous increase in torque when the throttle was opened while at maximum lean angles.

When I discussed how I was going to do my EFI, their main electronics engineer started clapping..... What I wanted to do (and later did) was to upload a fuel distribution curve similar to a Del'Lorto needle/tube (needle jet) combination and did not let the computer adjust it. I used a TPS, H2O sensor, Air temp sensor, and Hall Sensor for crank angle/rpm. This way I was using what I knew, but getting the benefit of 3 bar of fuel pressure and injector atomization. I had total control and could add fuel to make the fuel curve "imperfect" if need be. I used 2 injectors mounted on the engine side of the throttle valve and I alternated their firing so that I could rev upto 15000 rpm. That way each injector was mislead into thinking it was feeding a 7500 rpm max 4 stroke cylinder. In total I invested $1600 into the total system and had it running pulling load on the dyno in 3 hours.

Riley later says he timed the injector to squirt 10deg before inlet open and finish 10deg after inlet close

I have no airflow data, and once I have worked out how to post a few pictures I will. As was said they are a very clean carb for airflow with a flat slide. They do seem to self adjust for fueling as the air to fuel ratio's compared with the prior Mikuni powerjet reverse slides are similar. Once I have finished the setting up of the carbs I will give you more data, but that will be a few weeks yet.

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)

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.

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.

I too would be very interested in this transmission. please PM me.

You can't expect the carburation of a reed bike to remain perfect after the reed breaks, Dave; it will probably have a lot of blow-back and therefore a terribly rich mixture. You'd need to find the right combination of crankcase volume (large!), inlet tract diameter and length for a clean 24/7-carburation.
Which complicated reedblock are you talking about? The one with the two hinged reeds coupled by gears that you may have seen in www.pit-lane.biz?
That was the very first prototype, over ten years old now. It was over-engineered all right; just one hinged reed without any gears will do just fine.

What you are suggesting, two carbs, has been tried by a dutch Kreidler tuner: http://kreidler.nl/forum/viewtopic.php?f=5&t=38866 .
He didn't even bother with guillotines or reeds; just the normal piston-ported carb and a second carb connected directly to the crankcase.
In the video the jetting is off and he opens that second throttle way too early but nevertheless the contraption runs....

Attachment 254941

Made an adjustable PJ out of a model aero engine carb needle jet for controlling the PJ. Now to get one of those solenoids the Husaburg posted to shut off the PJ for a bit of extra over rev.

Made some progress with the shorter inlet tract and expect to get the lower mid range back again with a bit of fiddling with the carburation.

Just a little bit more and the single exhaust port engine with the RS pipe will be very close to EngMod2T's predicted power output.

Attachment 254940 125cc rotary valve with a 24mm carb and air cooled.

Measured 31 rwhp (estimated 34 crank hp) on the dyno tonight, red line is last night before the inlet tract was shortened and the jetting/ignition adjusted.

I have ordered one of Wobblys special kitset "A" Kit Pipes for a Suzuki GP125 ..... so hopefully 1 or 2 more hp and a wider spread of power. Then there is the ATAC idea for better low end.

Re the tiny bleed hole in the TZ powerjet tube - I always thought that this was a good idea to emulsify the fuel as it exited the dropper.
But years ago i did some wet tests on the flowbench with a VCR video camera ( pretty trick shit stuff back then ).
The Mikuni was a horror scene when played back slo mo,with huge "gobbs" of fuel exiting the main and powerjet.
We then stuck on a Lectron - wow, lovely fine mist of fuel from the back of the flat needle face - and it flowed 12% more air - size for size with a venturi 2mm smaller behind the slide.

Next is the current state of TeeZees GP125, here is the latest dyno curve digitised with 16% added to simulate crank power.
Then there is the sim with an actual RS early model pipe.
Then there is the new pipe of my design.
Of most interest is that in this case the sim is giving slightly too much crank power - but the shape and peak point are all but perfect.
I would be confident now that any change in the sim, would be reflected in reality on the dyno.
In my experience the later Dynojets like a twin roller 168 with Eddy current load control to slow the acceleration rate down ,seem to read around 5 to 10% lower
so this would put the sim and the dyno reading very close, as the shape is spot on now.

When using a simple powerjet nozzle the tip position matters in that no flow will occur until the slide is well past the exit hole, and there is sufficient airflow
to drag fuel up the feed tube above the bowl level.
With the aftermarket add ons and the ones as used by Lectron you can shorten the dump tube so that the flow will only occur at high slide openings,as well as high air flow.
These also have a built in "lag "control in that it takes time for the fuel to rise up the tube and dump out the exit into the air stream.
With a solenoid controlled setup all this is pretty much irrelevant as the flow can only occur when the solenoid is not powered up, and this
is TPS as well as rpm dependant inside the ECU program..
The carbs as used on the MX bikes has the dump tube very low in the bore as they added and subtracted fuel at low slide positions in those bikes.
For a race engine I bend the tube up to around 1/2 bore, as this is where the exit is on the Kehin SPJ carb for RS125/RS250 Honda.
And the general setting is the solenoid is powered up ie no flow below 4000 and 60% TPS and is powered up again at around 12400 to lean off the mixture and increase revon.
This causes a problem with Ignitechs that are used with only a capacitor, as at startup the solenoid is powered up, dragging all the voltage out of the ECU, so I convert the ECU output
to a 3 step truth table, and have the setting such that below 1500rpm the solenoid isnt powered.

The tube is thick walled and bends easily by simply levering it up.
You can take it out, but then when its bent it wont go back in,as its designed to be pushed in from the outside.
Here is the table

Gentlemen, I'd just like to poke my nose in here and say that I've been lurking in this thread for quite some time and it just keeps getting better and better. By far the most informative thread I've found on 2 stroke design. Thanks to all and keep at it. As a guy who plays with 2 strokes as a (very expensive) hobby, I really appreciate everything openly posted here. The fellow who rides the race RZs I build thanks you too.

LOL. Fair enough Frits, thats some perspective. Expensive is relative of course. In the last couple of months I've bought a TD2 project bike, a TZR250 for one of my projects and more parts and services bike related than my marriage could stand were it openly discussed.
In the spirit of the co-operation already in this thread, and considering that fuel injection was brought up earlier, here is the beginning of a prototype system I've been playing with. I'd appreciate any feedback, hopefully productive. If you'd like to say it won't work that's fine but please explain why?





Now some of you may recognize my name as a member of another forum where FI has been discussed,(I recognize some of your usernames), and may hold against me some things I said there. Please understand that my comments there were made because of my frustration with a poster there and his apparent arrogance and unwillingness to share information. Don't misunderstand me, I don't believe that it was required of him, but rather than refuse to answer questions he acted as though the questions were somehow beneath him. I would appreciate it if these pics didn't appear elsewhere. I'd rather it be running before I face the firestorm. Thanks.

edit. I really don't know why those pics are so small...sorry

Anything well just about anything can be made to work given enough time, money and more importantly determination.

I concept is great but why one throttle body?
What is the outcome you are after drivablity, fuel consumption,Tune-ability, emissions or performance. ?
The main issues i see is that carbs are light and simple and relatively specking. Ie no battery/alternator, fuel pump regulator ECU etc.
I am not knocking you because it is great to actually do it rather than just thing about it or just ruling it out.
What sort of fuel pressure are you envisaging?
I remember the Cagiva system involved huge pressures.
The biggest potential advantages i see with fuel injection are economy and emissions drive-ability but maybe, i am short sighted about this.

The one thing i did pick up from a few pages back was the split system with each set of injectors handling half the revolutions. So two injectors on each cylinder running each fueling alternate revolutions. Which should solve a few of the problems with doing it in the past.

You could also maybe alter the characteristics under overrun even possibly dial in some engine braking.
Maybe include a four stroke switch for slippery conditions and learner racers.

2011 Return of the two stroke. Possibly premature.
http://www.youtube.com/watch?v=goNP9...ia1uTNqMht_TCF

I see the EFI CR500 featured in Dirt Rider Downunder is sporting a carburetor now. What happened?
I thought we were looking at the future.

A collection of stuff i found interesting

Buried in there Neil is the Post regarding the Aprilia Fuel injection This could be out of context as i don't remember the origional quote?

Riley Will make the Super karts contributes to Pitlane makes closed ended Gudgeons as well the part prices for the Superkarts seem quite reasonable to but what was his background......http://www.brceng.com/250fe.html

Re the CTV did it come to anything Frits and ROB?

oh and speaking of CR500s and the future where is my jetpack...


"If I had thought about it, I wouldn't have done the experiment. The literature was full of examples that said you can't do this." --Spencer Silver on the work that led to the unique adhesives for 3-M "Post-It" Notepads

[dinamik2t]

When using a powerjet ... With a solenoid controlled setup ...
And the general setting is the solenoid is powered up ie no flow below 4000 and 60% TPS and is powered up again at around 12400 to lean off the mixture and increase revon.

Wob, could you post aproper AFR/ADV map incorporating the powerjet shut-off function -if it's not "business" info?

I remember a post of yours, saying afr would go from 12 to 14, so I tried the 13.5~14 value.
I tried setting it up like this:



Shutting it off at 12500, from 12 to 13.5Afr. Tuned length 860mm and 198° ex.
I can't get it to make any difference in overrev (from leaving it at 12Afr all the way).. Both times, engine RPM stop at 13000, with just a little more power with the PJ.

On the other hand, I tried finding the 'shut-off' AFR from the jet sizes. Area of MJ+PJ=Fuel-Air ratio.
2.55mm² (MJ 180) + 0.2mm² (PJ 50) = 0.083 (12AFR)
2.55mm² = x (1/x AFR)
This gives a ~13 AFR (reasonable?). I don't know if that's a good simplification though...

[TZ350]

Re the CTV did it come to anything Frits ROB?

CVT ... I am still working on mine. I am building a completely new lighter bike that has more of its weight on the front wheel and two engine setups for it, one conventional and the other will have a CVT transmission. It seems to take forever to get anywhere.

[Frits Overmars]

It seems to take forever to get anywhere.

Tell me about it. Luckily it will probably not affect the speed of the end product .

[Grumph]

Just so people get a handle on the reality of my situation re the F3 bikes.
One customer whos engine had done over 50 full noise dyno tests, took the bike to Taupo.
There it did 4 - 20 minute sessions as hard as it would go, bad front end issues, no brakes, and wrong gearing.
Max egt 1235 with 195/198 mains.
Pull the barrel and the pistons look like new - see the pic..
Now it has done another full day at Manfield with super rich jetting to try and nail the handling.No problems, needs attention at trailing part throttle, mid corner.
But in a straight line you " hang on for grim death ".

The other customer ran the bike for the first time with the same jetting, at sea level, after being told to go up to at least 210, and not exceed 1250 - the red lights ( 4 of them ) come on at 1260.
He didnt, do as advised.
First fast session it hit 1350 with all the lights flashing like crazy.
Carried on for 5 more laps till it siezed on part throttle.
I have never in 30 years seen an engine survive over 1300 F, ever.
Piston to bore is now over twice what it should be - surprise , surprise.
Now im told Wossner pistons are shit - the plating is shit - and by inference I couldnt tune my way out of a brown paper bag.
Am I angry - yes.
Easy to fix - yes.

Every one of us who has built motors for money has horror stories like this...."Picking customers" should be a required course for engine builders. I find a simple question "will you do what I tell you ?" and observation of the body language helps a lot....

[husaberg]

CVT ... I am still working on mine. I am building a completely new lighter bike that has more of its weight on the front wheel and two engine setups for it, one conventional and the other will have a CVT transmission. It seems to take forever to get anywhere.

I was meaning of the contact with Frits and yo with nasone32?

[wobbly]

The problem as I see it with adjusting the AFR trying to simulate a PJ being switched off is that this has two effects on the result.
It will increase the temp seen by the pipe, but I believe also the code does a calculation of the energy available in the fuel, and adjusts the power
that quantity will deliver - maybe in this case the two counteract each other exactly.
This is because max power is seen down at a rich mixture,around 12:1, closer to stoichiometric there is less power available, in theory and reality.

But the other thing you should realise is that although a solenoid powerjet is reducing the fuel delivered to the engine, it
is actually correcting the natural,progressively richening mixture coming from the carb, not reducing the AFR below what is was previously.

I will ask Neels about a workaround, but my reaction would be to use the pipe wall temp/rpm input screen,to increase the average temp in the pipe after a set rpm.
Going from a " normal " 50* wall temp to a 150* wall temp at 12,000 will for sure have the desired effect on the overev.
In reality the temp will increase gradually, so a temp ramp over say 1000rpm would simulate reality better.
I dont know if the code interpolates temp between the set points.

[F5 Dave]

Just so people get a handle on the reality of my situation re the F3 bikes.
One customer whos engine had done over 50 full noise dyno tests, took the bike to Taupo.
There it did 4 - 20 minute sessions as hard as it would go, bad front end issues, no brakes, and wrong gearing.
Max egt 1235 with 195/198 mains.
Pull the barrel and the pistons look like new - see the pic..
Now it has done another full day at Manfield with super rich jetting to try and nail the handling.No problems, needs attention at trailing part throttle, mid corner.
But in a straight line you " hang on for grim death ".

The other customer ran the bike for the first time with the same jetting, at sea level, after being told to go up to at least 210, and not exceed 1250 - the red lights ( 4 of them ) come on at 1260.
He didnt, do as advised.
First fast session it hit 1350 with all the lights flashing like crazy.
Carried on for 5 more laps till it siezed on part throttle.
I have never in 30 years seen an engine survive over 1300 F, ever.
Piston to bore is now over twice what it should be - surprise , surprise.
Now im told Wossner pistons are shit - the plating is shit - and by inference I couldnt tune my way out of a brown paper bag.
Am I angry - yes.
Easy to fix - yes.

A mate had to deal with same sort of thing (erm 10yrs ago), he was sending his RS barrel over to (I won't name) a UK RS125 specialist & doubled up with another racer to save on postage, both got some porting & a replate.

Well the other guy's bike seized next time he rode it & all my mate heard was this guy is rubbish blah blah. I've heard the same story about several other prominent names as well but I figure that that is part & parcel of the buss.

But what is interesting is the amount you've cut the rear transfer feed back in the RZ cases.

[wobbly]

What you find with cylinder reeds on an engine like the RZ is that as you approach 100CHp the inlet STA becomes the limiting factor.
The pistons have huge holes in them ( a Blaster basic design ) and it has two big boost ports up the back, as well as big elongated
Boyesen ports down the sides.
To get the 100 Hp it needed more intake, so dropping the Boyesens even more needed bigger cutouts into the case.
Thus pulling back the case transfer duct rear edge very close to the stud, gave easy access for the flow thru the Boyesesn bottom edge into the case.
I dont like the idea of cutting away the rear wall of the rear transfer, to get inlet flow area, as this flow is at right angles to the flow thru the duct - to the port.
It may work fine - but doesnt seem intuitively "right ".

[dinamik2t]

Good idea the one with wall temp, I will try it.
Thanks for the assistance Wob!

(I believe there is no need to tell you 'well done', you would know your capabilities better than anyone, but it's very encouraging to hear from a happy customer at least )

[F5 Dave]

What you find with cylinder reeds on an engine like the RZ is that as you approach 100CHp the inlet STA becomes the limiting factor.
The pistons have huge holes in them ( a Blaster basic design ) and it has two big boost ports up the back, as well as big elongated
Boyesen ports down the sides.
To get the 100 Hp it needed more intake, so dropping the Boyesens even more needed bigger cutouts into the case.
Thus pulling back the case transfer duct rear edge very close to the stud, gave easy access for the flow thru the Boyesesn bottom edge into the case.
I dont like the idea of cutting away the rear wall of the rear transfer, to get inlet flow area, as this flow is at right angles to the flow thru the duct - to the port.
It may work fine - but doesnt seem intuitively "right ".

Ahh yes, had to look at pick of my 496 barrels, thanks for explaination.

[wobbly]

Yea, so here are the two options to increase inlet flow.
I believe the case entry is more effective.
But who knows, maybe both will make more power together.

[Flettner]

Yes Wobbly I've got customers like that too! They just won't listen, you just know they are going to crash their gyro. Usually they do. Good business on the rebuilds though.