ESE's works engine tuner

[wobbly]

The cooler the water, the cooler the case and more importantly the cooler the transfer and Ex port ducting.
This maintains charge density, as well as keeping cool the slug of A/F sitting in the Ex duct waiting to be shoved back in
by the rear cone wave action.
With a new water regime I developed for KZ2 kart engines we run between 40 and 45*.
A 125 cylinder will drop at the very least 2 Hp, when lifted from 50 to 60*C

[TZ350]

Happy afternoon playing on the dyno, making some progress with improving the drivability.

Green line is 20% throttle the other curves are 30-40-50-60-70-80-90-100%, Interesting that 90 and 100 are basically the same.

Making power is not my EFI tuning issue, the big problem for me has been getting the engine to pick up again after closing the throttle when slowing down for a corner.

Things have started to improve as I carefully shave the map down in the low throttle rich areas 0.5% a time.



Making progress, in the area where the 20% Green line is, the motor is almost behaving it self. I expect that with some more careful work sanding the map down in the rich areas either side of the green patch things will get better yet, maybe even ride-able.

[husaberg]

Happy afternoon playing on the dyno, making some progress with improving the drivability.

Green line is 20% throttle the other curves are 30-40-50-60-70-80-90-100%, Interesting that 90 and 100 are basically the same.

Making power is not my EFI tuning issue, the big problem for me has been getting the engine to pick up again after closing the throttle when slowing down for a corner.

Things have started to improve as I carefully shave the map down in the low throttle rich areas 0.5% a time.



Making progress, in the area where the 20% Green line is, the motor is almost behaving it self. I expect that with some more careful work sanding the map down in the rich areas either side of the green patch things will get better yet, maybe even ride-able.

That's the problem that Cagiva had with the 500E ,as the injection keeps on pumping fuel on overrun.
A pumper carb does the exact same thing, not as problematic on a kart or a car, but can lead to highsides on a bike, when it finally clears the full crankcase and chimes back in.
http://www.kiwibiker.co.nz/forums/al...hmentid=302540

[Haufen]

TZ, if the injector is only slightly too big, then you might be able to work around the problem by retarding the ignition in the low throttle opening range until you find / get a smaller injector.

This way, you need more throttle opening = more air for the same power which should get you closer to the AF ratio you need for a smooth pick-up. If this does not improve pick up, then your rich pick up situation could also be caused by a puddle of fuel somewhere in the engine.

[TZ350]

TZ, if the injector is only slightly too big, then you might be able to work around the problem by retarding the ignition in the low throttle opening range until you find / get a smaller injector.

This way, you need more throttle opening = more air for the same power which should get you closer to the AF ratio you need for a smooth pick-up. If this does not improve pick up, then your rich pick up situation could also be caused by a puddle of fuel somewhere in the engine.

I will try that.

That's the problem that Cagiva had with the 500E ,as the injection keeps on pumping fuel on overrun. http://www.kiwibiker.co.nz/forums/al...hmentid=302540

Thanks Husa, I haven't got it as ride-able as the Cagiva yet. But their low throttle high rpm fueling issues are exactly my problem too.

[husaberg]

I will try that.



Thanks Husa, I haven't got it ride-able as the Cagiva yet. But their low throttle high rpm fueling issues are exactly my problem too.

if it had a reed valves you could put spacers under the reeds so they don't fully close.
What it needs is a way of interrupting the fueling enough on over run without it causing it to seize. (which would be a fine fine line)
what do the sensors actually read out on overrun conditions?
Maybe it needs skip strokes or a rider that doesn't ever throttle off. AN idle set to 4000RPM

[speedpro]

With the throttle closed there is a lot less air flowing through the engine. Completely stopping the fuel above certain revs on a closed throttle may not be such a big problem. With no fuel there will be no combustion and without the airflow the oil remaining will possibly continue to lubricate things sufficiently. With no fuel at all being injected on a trailing throttle at revs it might come back on throttle a bit cleaner as it wouldn't have to clear that puddle.
With an autolube system when the throttle is closed the oil injection essentially stops but the engine could still be doing a lot of revs. Think about a long downhill.

[Grumph]

With an autolube system when the throttle is closed the oil injection essentially stops but the engine could still be doing a lot of revs. Think about a long downhill.

One of the quoted benefits of the autolube systems when they were introduced was just that - no seizures coming down hills with a shut throttle as there is always a minimum of oil coming in.
If you're worried about lube vs fuelling, you could always refit the autolube so as to separate the two functions...at least until you've got the mapping a bit closer. Eliminates one variable anyway...

[husaberg]

With the throttle closed there is a lot less air flowing through the engine. Completely stopping the fuel above certain revs on a closed throttle may not be such a big problem. With no fuel there will be no combustion and without the airflow the oil remaining will possibly continue to lubricate things sufficiently. With no fuel at all being injected on a trailing throttle at revs it might come back on throttle a bit cleaner as it wouldn't have to clear that puddle.
With an autolube system when the throttle is closed the oil injection essentially stops but the engine could still be doing a lot of revs. Think about a long downhill.

One of the quoted benefits of the autolube systems when they were introduced was just that - no seizures coming down hills with a shut throttle as there is always a minimum of oil coming in.
If you're worried about lube vs fuelling, you could always refit the autolube so as to separate the two functions...at least until you've got the mapping a bit closer. Eliminates one variable anyway...

Maybe a hybrid with the throttle position delivery rate on the autolube pump disconnected,so just a small amount would be delivered at all revs used in tandem with premix.
Or maybe just a simple auxiliary injection system like the KTM used just to do over run only.

[wobbly]

NSR250 Hondas have a solenoid control on the oil pump - at high rpm with closed throttle the pump runs at full output.

[TZ350]

Completely stopping the fuel above certain revs .... With no fuel at all being injected on a trailing throttle at revs it might come back on throttle a bit cleaner as it wouldn't have to clear that puddle.

Will try a couple of zeros at the high end of the map to see what happens.

NSR250 Hondas have a solenoid control on the oil pump - at high rpm with closed throttle the pump runs at full output.

That would be possible.

To save weight and mechanical drag I have long ago done away with the internal parts needed for a mechanical auto lube pump.

But I could fit a small diaphragm pump and solenoid switch that the Ignitec ignition uses for the power jet and re configure it to switch on the oil solenoid to oil the engine at high rpm and closed throttle.

.... If I could use engine lube to oil the gearbox then I could just switch some oil discharged from the gearbox pump to the engines auto lube system when needed.

In fact I probably could use the current ATF gear box Auto trans oil. Maybe not the best there is for an engine but I bet it is plenty better than nothing. Also it seems compatible with the pre mix we use as plenty of our bikes have sucked their ATF gear box oil and kept going.

Maybe just a simple auxiliary injection system like the KTM used just to do over run only.

A high rpm closed throttle solenoid oiler may be quite easy to do, thanks for the ideas.

[Grumph]

A high rpm closed throttle solenoid oiler may be quite easy to do, thanks for the ideas.

High RPM, closed throttle - high vacuum. Vacuum triggered switch or valve ?
I'd point out in the interests of KISS that Bultaco used a drip feed into the inlet for supplementary oiling....

And i'm old enough to remember wiring Suzuki T20/T500 pumps about 1/4 open as an addition to what was in the fuel.

[morini155]

Hello, i like this forum and i have a question: i work on a Yamaha DT 200 engine, but i want block the YPVS valve on a fixed position. Can match the valve operation benefits with a proper tuning of exhaust pipe? Can have a broader powerband, from 5000 to 9000 rpm?

[wobbly]

In 2 words - no way.
An even better idea is to dump the spinning PV regulator and drive it with cables and a servo.
More power is easily dialed in below the best operating range of the pipe - so it can be tuned for better mid or top end depending on the end use.

[morini155]

The engine its for use on off-road use, trail woods,etc, and i see the Yamaha Blaster 200 quad engine perform well and this engine its no YPVS. The Banshee 350 its another example.
For this use whats guidelines on ports timing and compresion ratio?