ESE's works engine tuner

[emess]

Frits, many many thanks for a great artical ( and the previous 300 odd posts)

I have learned more in the last year reading posts from you, Wobbly and others than I have in the previous 50 years of 'playing' with two strokes.

I do not have much to offer to the discussion (apart from more questions!) but some may find this useful. Rather than use the site search which usually fails, use Google so to search this site use an ordinary search phrase and after it add

site:www.kiwibiker.co.nz

for example

Frits priceless site:www.kiwibiker.co.nz
or
Frits pisa site:www.kiwibiker.co.nz

the same will work for other sites with the appropriate site address

Mick

[Frits Overmars]

.... Rather than use the site search which usually fails, use Google so to search this site use an ordinary search phrase and after it add site:www.kiwibiker.co.nz
for example
Frits priceless site:www.kiwibiker.co.nz or Frits pisa site:www.kiwibiker.co.nz
the same will work for other sites with the appropriate site address
Mick

Just what I needed, Mick. Site searches usually fail, not just on Kiwibiker, but on any forum I visit. Your approach really works. Thanks very much for the tip.

[dinamik2t]

Frits, I've just returned home and admittedly I haven't given it much thought. The thing that came into my mind while reading your power average explanation is using a deviation factor (like std deviation in statistics or the ripple factor in electronics) to give more info about such irregularly variating quantities, eg a power curve.

I believe it could be simpler to understand and make use of. Still won't cover a zero acceleration condition, but what do you think?

[Frits Overmars]

Frits, I've just returned home and admittedly I haven't given it much thought. The thing that came into my mind while reading your power average explanation is using a deviation factor (like std deviation in statistics or the ripple factor in electronics) to give more info about such irregularly variating quantities, eg a power curve.

I believe it could be simpler to understand and make use of. Still won't cover a zero acceleration condition, but what do you think?

I don't think it will yield the same outcome; it must be able to handle zero acceleration conditions.

[jasonu]

.

Soon there will be a cheap and easily available facility for custom cnc parts to be made for buckets

Cheers,

-Sketchy

Bucket racers are a notoriously stingy pack of tight arses, I hope you are not planning on getting rich quick from this scheme...

[F5 Dave]

He's well aware being one himself, but good luck Glen, hope it works out well 'cause you have the skills to make some good kit.

[136kg136ps]

So Frits,is the zero acceleration phase due to gearshifts and/or the associated cessation of the pipes effect on engine power?Please forgive my questions if they are repetitive,I have a hard time wrapping my mind around the dynamics of two strokes as all my engineering background is electrical and gas turbines both far simpler than these motors apparently.

[Sketchy_Racer]

Bucket racers are a notoriously stingy pack of tight arses, I hope you are not planning on getting rich quick from this scheme...

No money to be made from bucket parts, I have some specialist contracts that are there to make the money Bucket parts are for fun.

[Frits Overmars]

So Frits, is the zero acceleration phase due to gearshifts and/or the associated cessation of the pipes effect on engine power?Please forgive my questions if they are repetitive,I have a hard time wrapping my mind around the dynamics of two strokes as all my engineering background is electrical and gas turbines both far simpler than these motors apparently.

There can certainly be zero acceleration phases in the occurences that you mention, but that is not the issue when converting power graphs into power range graphs.
The power to range conversion algorithm must be able to handle zero acceleration situations. Nothing to do with engine dynamics in this case, just math.
By the way, if you really want to grasp the difference between the 'area under the curve'-approach and the acceleration approach, put another 97 yellow rectangles on top of the 3 rectangles between C an D in the picture below, and repeat the area-calculation and the acceleration-calculation of average power.

[136kg136ps]

I think I get it,the added blocks just reduce that segment to 1/100 sec vs. 1/3 sec.Even if it was instantaneous it wouldn't alter the time but by the original 1/3 sec?Having nearly negligible effect on average power.
One could use this calculation and datalogging to determine the best gear ratios and final ratio for each track.

[jasonu]

No money to be made from bucket parts, I have some specialist contracts that are there to make the money Bucket parts are for fun.

Nice one mate. I wish there was access to affordable services like you are offering when I was raceing. Good luck with your venture.

[Frits Overmars]

I think I get it, the added blocks just reduce that segment to 1/100 sec vs. 1/3 sec. Even if it was instantaneous it wouldn't alter the time but by the original 1/3 sec? Having nearly negligible effect on average power.

You got it .
The above suggests that effort is better spent filling dips in the powerband rather than trying to move the peak a little higher; the weakest link is always decisive.

Here is a story I use to make young riders understand:
"We are on a circuit, 2 km long. You ride the first kilometer with a speed of 100 km/h and the second kilometer with a speed of 0 km/h. Then what will be your average speed over one lap?"
About ten out of ten answers will be: "50 km/h". But of course you guys won't fall into that trap, will you?
This time next year you will still be standing halfway round that circuit, because with 0 km/h you won't get any further. So the average speed will be zero.
The lesson to my young riders is: racing is not about being fast. It is about not being slow anywhere.

There is also a second lesson:
Working on your engine may improve your lap times a couple of tenths. Working on your tires and suspension may be ten times more effective.

[Flettner]

TZ, box turned up today. Interesting.

[TZ350]

I am looking forward to hearing what you think can be done.

I was in at work this afternoon thanks for the cylinders and I see the F81 has been collected. I hope you saw the EFI stuff on the bench, I would be interested in what you think of it.

I am getting some bigger injectors, 650cc/min and a bigger 45L/hr pump. The plan is to use a 650cc injector paired with a 460 and 25L pump paired with a 45 that is switched on by the Ignitec at WOT above 10K rpm or there about.

I am keen to follow your advice and inject into the transfers while the transfer ports are open. And that means there is only 1/3 of the time (120 deg duration) to complete the fuel injection cycle.

So I need much bigger pumps and injectors compared to injecting into the inlet as the inlet is open for 2/3 of the time (230 deg duration) or the crankcase for possibly up to 100% of the time (360 deg duration) where a 25L pump and a smaller injector would do.

[Frits Overmars]

I am getting some bigger injectors, 650cc/min and a bigger 45L/hr pump. The plan is to use a 650cc injector paired with a 460 and 25L pump paired with a 45 that is switched on by the Ignitec at WOT above 10K rpm or there about.

A carburetted engine will need about 0.35 liter per wheel-HP per hour; it may be even less with injection.

I am keen to follow your advice and inject into the transfers while the transfer ports are open. And that means there is only 1/3 of the time (120 deg duration) to complete the fuel injection cycle. So I need much bigger pumps and injectors compared to injecting into the inlet as the inlet is open for 2/3 of the time.

Bigger injectors yes, but why a bigger pump? (I assume one pump will suffice). It will run continuously anyway; you will only need an airspring-loaded buffer volume between pump and injectors.