ESE's works engine tuner

[Ocean1]

I don't know about variators, but if they were toothed or fixed pulleys, the first option would be the one, since it provides the belt with more wrap-around on each pulley

As long as the belt's designed to flex backwards...

[TZ350]

Page 1110 progress on the EFI thing.

I have made three basic mistakes.

1:- using the biggest injectors, I should have used the smallest injectors that will support maximum power. Because the smaller injectors can be dialed back by the CPU for a wider range of tunability. The big injectors are forced to stay on for the minimum injection time and flood the engine.

2:- Had even spacing between the columns of the Alpha-N map. I needed to reduce the number of columns in the fat areas of the map and use them in the steep areas to reduce the size of the steps between them.

3:- Similar thing with the rows on the Alpha-N map, I had to many rows in the power area where things don't change much and not enough in the lower (below 50% TPS) area where things are changing rapidly and wound up with steps that the CPU found difficult to bridge especially while it was also trying to decide when to swap between high and low injectors.

I think I have shot myself in the foot again.

After the poor showing at Taumarunui where the bike would not come back on the throttle I thought I had better run it up on the dyno with the Ecotrons Procal tuning program displaying the Gauge monitoring screen in the hope of seeing what was going on.

The bike would start and trickle out onto the track easily enough and it would fly like a cut cat when it was shown a bit of stick. But it had two real bad faults, at about 8,000 rpm it would jump around like a demented kangaroo and when it was shut off at high rpm it would not come back on the throttle until the rpm had dropped under 7,000 rpm or so.

I thought it may be to rich/lean at lower throttle settings on over run at high rpm or it needed some adjustment to the throttle blip virtual fuel pump. But no amount of Map fiddling improved things.

Sorry about the jerky video but that is the bike shaking me around as I was recording the gauges. Its not dangerous to run a bike up full tit on the dyno by yourself with one hand while trying to record video with the other - yeer right its not dangerous.

Top left gauge is rpm and it tops out close to 13,000. Top right is the TPS and the two gages on the bottom right are for the injectors. Injector 1 to the left, Injector 2 to the right.



You can see injector 1 increasing in pulse width until it switches over to injector 2 at about 8,000 rpm, just where it starts to jump about. Then Injector two stays at 1.7ms right up to 13,000 ish rpm.

Close the throttle and injector 2 stays at 1.7ms until the rpm drops back below 7,000rpm and the system switches back to the smaller injector 1 at which point the engine will respond to the throttle again.

On over run above the changeover point the engine won't respond to small and medium throttle openings but at higher rpm it will jump back into life when given full throttle.

Previously I had been wanting to get as much fuel in as possible in the shortest amount of time and I had made injector 2 as large as possible and injector 1 was much smaller and only for starting and off pipe running below 8,000 rpm. The smaller the injector the more adjustable it is with the fuel map.

Both injectors have a minimum open time of 1.7ms and what I think is happening is that the big injector is too big and even at its minimum open time it drowns the motor at anything less than near full throttle.

And the jerking at 8,000 rpm is the EFI being confused about whether to use the injector that is to small or the injector that is to big.

I think Injector 2 needs to be smaller so it gets held open over a greater range of time from say 1.7ms at small throttle openings and high rpm to 3.5ms for full throttle at high rpm.

At the moment the EFI works well with injector 1 but it has no adjustment with injector 2, its all or nothing, actually injector two is virtually full on all the time above 8,000 rpm because it can't be run any slower than 1.7ms it needs more adjustment and we can only get that by going to a smaller injector because a smaller injector would need to be held open for longer than the minimum 1.7ms.

To get the greatest range of adjustment out of a fuel injector you need one that is only just big enough to do the job. I think I have been running one that is way too big for the job and even on minimum open time it is drowning the motor on overrun.

Instead of thinking big injector to get loads in quickly I think to get best throttle response I need to think smallest injector possible that is only just big enough to do the job at max fuel demand (max torque).

Tomorrow I will swap out the big injector 2 for a smaller one and see how that goes, here is hoping ....

Attachment 308248

Ok after months in the wilderness I finally figured it out. I was right about needing smaller injectors.

So it looks like, to maximize tune-ability you need to minimize the injector size......... in hindsight its so obvious really ....



Now that I have smaller injectors fitted, on the bottom right gauge you can see the number 2 injection pulse width increasing and decreasing and it is coming back onto the throttle much better now that the EMS has some pulse width range to play with.

Not perfect yet but very very promising.

Attachment 308315

Making progress with mapping the fuel injection.

Did a series of runs at different throttle openings 100-90-80-70% etc and it fell apart at 40%.

I will have to sit down now and look at the recorded run data to see why, it may just be to rich or something else, like the injectors are still to big or not crossing over nicely at 8-9,000 rpm.

Injectors turned up from Ecotrons today, four days from date of order and two of them were weekend days, pretty good service in my books.

Attachment 308623

I fitted a smaller injector and did a bunch of runs at different throttle settings. Interesting that the 60, 50 and 40% runs carry on out to close to 13,000 rpm.

Attachment 308625

Blue line is the TPS. 100-90-80-70-60-50-40% throttle settings. It is certainly throttling and coming back onto the power much better. I will have to analyse the data to see if I can use an even smaller injector.

Attachment 308624

Just by changing the central injector (and the injector size in the EFI software) I got the Blue line, I am not sure what that means as by rights, it was the same Alpha-N map so I was expecting the curves to be the same.....

The EFI lesson I learnt last month was, that to get the greatest range of tune ability I needed to use the smallest injectors possible that will still do the job. I know, pretty obvious, but there you go.

Attachment 308855Attachment 308856

I read the Ecotrons EFI manual and saw that the map must have as many even steps as possible and I thought that meant dividing the rpm range up as evenly as possible, seemed logical, but wrong again.

The bike bucked around swapping between the staged injectors as the EFI struggled to jump from one cell to another on the steeper parts of the fueling curve.

I guess what they really meant was that the changes between cells need to be as even as possible.

So I don't need even spacing between the rpm break points and can have big or small gaps between them so long as there are no big steps between adjacent cells.

That means I can straight line it between say idle and where the fuel demand just starts picking up around 7,000 rpm. And once again use a straight line after peak torque where the fuel demand is relatively steady again.

The straight line does not have to be horizontal, it can tip up or down, its just a line between two points on the map that may be several thousand rpm apart but covers an area of relatively similar fuel demand.

By straight lining where I can, I now have spare rpm break points to use to smooth out the map where the fuel demand is rapidly increasing with increasing torque.

Attachment 308853Attachment 308854

From left to right on the model, the first cell covers 4,500 rpm the next 1,500 rpm and the next only 250 rpm but the steps between the cells are relatively the same, ie a smoother map. Anyway I hope this is what they meant.

Attachment 308859

I can now throttle on/off pretty well and do a series of part throttle runs, the last one is at 30% TPS, it looks a bit lean.

Attachment 308857

Its not perfect but is running a lot better, so for what its worth here is the current Alpha-N map.

Yep, just like a large house party with interesting people.

Attachment 308890

The EFI is going better than ever but the evening ended in a woopsie .....

Attachment 308889

I was able to do several really good all gear runs with the bike coming back onto the throttle very nicely.

But my dreams of being the first persion to run an EFI 2T in a real F4 race on Sunday vanished when I felt the familiar overrun death shudder,

Attachment 308891

Getting pretty hot, interesting stain at the top of the combustion chamber where it looks like the transfer streams sweep up into the head.

Attachment 308888

Very dry in the bore and scratches that look like evidence of the ring ends butting up from over heating and the ring scraping the bore clean. Know more tomorrow when I get the cylinder off. It will be interesting to see how much oil there is in the crank case.

Attachment 308969Attachment 308970

Bit of quick work with a file and a light hone and everything is all good, even re used the piston ring, 2T's are so easy to work on

Attachment 308968

Dyno runs from from 100 to 20%, looks OK so hopefully back on for Sunday.

Not sure about the ring gap now, looked good when I took it apart, I think you are probably right about the lean seize as it was definitely getting no fuel at closed throttle.
There is a software switch in Ecotrons where you can turn the fuel off on over run..... and I had to try it just to see what it did, as you do.

You were on the money, I have been dialing in more fuel, heaps more fuel in the area of the Map that if it was a carb it would be the pilot and slide plus the very first bit of the needle.

Comes back on the throttle much better now, hopefully get to ride it tomorrow.

No, because it ran very well every where with 50% plus TPS. It was easy to get the EFI running in the "main jet" area. But tuning the lower parts of the Map is taking a bit of patience.

It would rev out real hard, shut the throttle and it would not light up again until the revs had dropped below 8 or the throttle was opened past 50%.

I had no idea what a Map should look like or if it was rich or lean until I put the O2 sensor back on it.

Been taking lots of dyno runs at part throttle and comparing them as I make changes to the Map.

Carburetors are great because of their analog ability to change the fuel delivery with changes in air flow at the same throttle setting.

EFI, well EFI is not forgiving at all.

Attachment 309236 16 Alpha-N map lines with most of them concentrated in the upper power area of the graph.

Back to the EFI thing. The Ecotrons Alpha-N map has 16 rows to work with and I had concentrated them in the area where the power is, as you do. Well that turns out to be a mistake because there is not much difference in fuel demand per cycle between 100% throttle and 90 or 80 or even 70 at max power and virtual no difference at all above 40% in the 3 to 6000 rpm range.

The big jumps were between the lower throttle settings where there was not much excitement happening, well the mistake is that the CPU has a hard time bridging the big gaps below 40% especially when it is also trying to swap between low and high injectors at the same time.

Attachment 309235 16 Alpha-N map lines more evenly spread so as to not have any big jumps between them.

Under 35% throttle is pretty unexciting power wise but on the track its a big deal as far as on track drive-ability is concerned. So for the next attempt I am going to use more Map lines in the lower area where things are changing rapidly with throttle position and less in the upper area where things are not changing so much, the power at 80% throttle is not very much different to 100%.

As it turns out, it was a mistake to concentrate my map in the power area, but I guess I will forgive myself.....

[senso]

Senso, now that you have cut your CRM50 cylinder, is it possible to measure the thickness of the sides of the exhaust port near the cylinder wall?
I am wondering how wide we can go at the top of the port before breaking through

Sure, next weekend I will cut it a bit more, measure and post here the results, its a pleasure that I can help someone!

Wobbly, the 600mm^2 are a direct measurement from the port-map, so no downdraft angle included.
I forgot about the magic that happens with 190º of exhaust, I will see how much it cost to skim 2mm off the top of the cylinder.
Regarding the metal spraying, I know the technic but I don't know how thick it can go, because I would need about 3mm to be on the safe side, maybe some silicon bronze welded with an oxi-acetylene torch, or maybe stick welding might work?

Regarding the exhaust duct size, I measured a 100% original cylinder and it measures 27mm wide and 24mm tall, or in other words, it as an oval exit.

In any case, my next cylinder is already bored so I can't do any welding to it.

[wobbly]

You can build up as much as you want with metal spray - but yes bronze weld would work.
Stick welding i would not recommend in cast iron as the localised heating can make it crack very easily.
The Ex bore area must be multiplied by the duct down angle cosine as this is the true port area.
Your 600mm2 at 30* down becomes 519mm2 times 0.9 = 419mm2 exit = a 24.4 round exit.
An exit ellipse at 27 by 24 is 509mm2 - still way too big.

[peewee]

well im starting to get the hang of this stuff alittle better. still far from a professional though . had trouble yesterday because i wasnt quit getting enough heat into the work area so i got a different torch that seems to work better. put a nut and bolt in there so that stuff wouldnt fill up the nut pocket

[Ocean1]

. had trouble yesterday because i wasnt quit getting enough heat into the work area t

If you're using oxy acetylene then try turning the oxy almost off, so you get soot from the flame. Coat the cleaned work area with soot. Retune the flame to neutral. Before starting to weld heat the whole piece but concentrate progressively more and more on the weld area. At some point the soot will start to vanish, you'd just a couple of degrees from hot shorting, turn the heat down a tad and start applying filler.

[peewee]

i was using just straight mapp gas. got 2 different burner attachments and one gets hotter than the other i believe. was gonna try some mapp gas and oxy but figure i would give these burners a try first. still might try the mapp and oxy. i got quit a few junk cylinders i can practice on and see what works good. also i did preheat the cylinder in the bbq to about 300f or so. problem is its in the backyard and wind blowing etc. soon as you open the lid you lose a ton of heat. still its was better than no preheat. might turn the bbq up a notch next time also. ill get it figured out sooner or later

i could be wrong but i thought i read you werent supposed to use acetalyne with this low temp rod. something about acetalyne being to dirty or something. again i could be wrong

[seattle smitty]

Peewee, how about oxy-hydrogen (rent a bottle), which is what the old-timers used when welding aluminum in the days before TIG was widespread. It's clean, and burns somewhat cooler than oxy-acetylene. I'm really interested in your commentary on this! Some of the low-temp rod I've tried seems to work well on beer cans, which are nearly pure aluminum, but don't want to "tin" very well on anything else (beer cans are what the fellers selling this rod at swap-meets always use). Keep it coming.

From the excellent photos from Senso, it appears to me that there's just enough metal that he could pick up a few degrees of exhaust-open timing by grinding a small 45-degree bevel in the upper edge of the port. Not only is this less work than making a radiused corner (or opening up the whole upper surface of the port), my notion (subject to anyone's correction) is that a bevel creates a more well-defined edge than a radius, and thus maybe a crisper exhaust signal. Yet it's less likely to catch on the ring than a port cut back at its existing 30-degrees or whatever. This was the thinking among some of us Seattle-area outboarders forty years ago so I suppose it is hopelessly primitive, but there you are.

[peewee]

smitty the little mapp torches will get it hot enough, just takes alittle longer than a big full size torch. also i wasnt using oxy, just straight mapp. they have a mapp oxy set up at the local home depot down the street which im sure gets quit a bit hotter than straight mapp. problem is the oxy bottles are only 1.4 lb and only last about 10min according to the video i watched, and they cost $10 a bottle. im not concearned about the money but i need to get alittle faster first. maybe after i get more practice and can get alot of work done in 10min then i might give it a try but right now im still trying to learn the ropes of this stuff. gonna play with the torches i have alittle more untill i get the hang of it

[husaberg]

I'd get a shorter belt, and let it tension with the pulleys like it's meant to.

I would have thought no tensioner was appropriate as the moveable sheave increases and decreases the amount of belt needed as it moves in and out. That is how it works on my Polaris Sportsman 700 twin quad anyway.

https://www.google.com/search?q=pola...ms%3B480%3B360

Is it one of these set up though........

In the first picture you can see the horizontal spring, nested in the frame. The complete engine, including the pipe, is hung by the head (they do that to engines in France; for humans they have the guillotine).
The spring keeps the V-belt in tension. And in case you want to kick the revs up a bit when exiting a corner, there's a foot pedal with which the rider can put a bit more tension on the belt and thus force the primary heaves wider apart and lower the gearing.

But you don't want to go there, TeeZee. Only one heave of the front pully moves axially; the other front heave and both heaves of the rear pully are fixed.
That not only means that the range from shortest to longest ratio is only half of what it could be on a decent vario; it also means that the belt is forced to run skew most of the time.

click on the arrow after Frits to see the pics if I can't be assed bring them through

[adegnes]

Is it one of these set up though........


click on the arrow after Frits to see the pics if I can't be assed bring them through

Yep, same system, thats why I need the tensioner now that my engine is stationary (it's mounted with sliding bushings to let it move side to side - eliminates the belt misalignment with just one variable pulley)

Is it "heave" or "sheave"?

[Ocean1]

i was using just straight mapp gas. got 2 different burner attachments and one gets hotter than the other i believe. was gonna try some mapp gas and oxy but figure i would give these burners a try first. still might try the mapp and oxy. i got quit a few junk cylinders i can practice on and see what works good. also i did preheat the cylinder in the bbq to about 300f or so. problem is its in the backyard and wind blowing etc. soon as you open the lid you lose a ton of heat. still its was better than no preheat. might turn the bbq up a notch next time also. ill get it figured out sooner or later

i could be wrong but i thought i read you werent supposed to use acetalyne with this low temp rod. something about acetalyne being to dirty or something. again i could be wrong

Not sure what rods you're using but alloy "braizing" rods have been around for a while and I used to use oxy acetylene quite successfully.

If you're managing with MAP gas but are a bit short of grunt then track down a half a dozen refractory bricks and build a little wall, (and roof?) around the work-piece leaving just the weld area exposed.

Just be careful of getting it too hot, may even be a good idea to track down some thermo-crayons or similar from your local welding supplier.

[Frits Overmars]

I think there is still a bit of exhaust area to be gain, but I'm kinda shy to square the exhaust port and then have the piston rings stuck in it, what is your opinion about the shape Frits?

is it possible to measure the thickness of the sides of the exhaust port near the cylinder wall? I am wondering how wide we can go at the top of the port before breaking through

You don't need to go any wider, Senso. In fact you've already gone to wide. With your 80% port width you need huge radiuses in the corners in order to keep the piston ring alive (and you would need the same size radiuses at the port bottom, so it looks as if you've been lucky so far not to break a ring).
70% port width is optimal. The total port area will be less but thanks to the tighter corners that it will allow, you'll have more area above the transfers, where it counts.
To be precise, it's not the area that counts, but the product of each mm² of area, multiplied by the number of crank degrees that it is open before the transfers open. You've guessed it: the blowdown angle.area.

[Frits Overmars]

In case you're wondering what you can get away with: the top and bottom of each window where a piston ring passes over, should have an elliptical shape.
Below you see the formula with which you can establish these shapes yourself, and the minimum safe limits for the optimal port width of 70%.
But since elliptical shapes are difficult to produce and measure, I've also converted the 70% port-ellipse shapes to multi-radius shapes for you.

[wobbly]

One thing I would add re port widening is that it is a mistake to go directly to the straight sides ( even as shown in Frits drawing).
In the vast majority of cases the best way forward is to simply widen to the max above the transfers, leaving the bottom of the port completely stock.
There is no gain at all making the port wider below the transfers and alot to gain by reducing the duct volume, and helping to prevent direct short circuiting from the A
port front edge.
If you are going all out,then raising the floor to get it several mm above BDC and increasing the bottom corner rads does both - reduces the volume and the short circuiting.
Near on every cylinder made to date will benefit greatly from this approach, from a Banshee to all the KZ2 engines - ( if you can get away with adding material to the casting,as that is actually illegal under the CIK regs )