ESE's works engine tuner

[lohring]

We probably ran shorter than 5 second pulls when we tested 26 to 35 cc two strokes. We tested from 12,000 rpm to over 20,000 rpm. That represented the run up time into the traps for our straight line speed attempts. We had issues with weird spikes from time to time. We had a direct connected flywheel without an over running clutch. We measured flywheel rpm only. The magnetic sensor was sometimes erratic at the higher rpms. A Hall effect sensor might have been better. I usually imported the data into an Excel spreadsheet and averaged three identical runs to help average out run to run variations.

Lohring Miller

[ApolloMotoMoto]

Use an acceleration time that is equivalent to what you are going to have when you ride it. Ideal case: the acceleration time in each gear is the same on the dyno and on the road. For that to be the case the roller has do be twice the weight of the bike including rider.

As long as you are unsure about jetting and ignition timing, fuel supply etc, use a shorter acceleration time as it is less likely to destroy an engine with lighter load. Once you are more comfortable with the setting you can switch to longer pulls, using a higher gear. Extra long / longer acceleration times would be the equivalent to driving uphill and vice versa.

We probably ran shorter than 5 second pulls when we tested 26 to 35 cc two strokes. We tested from 12,000 rpm to over 20,000 rpm. That represented the run up time into the traps for our straight line speed attempts. We had issues with weird spikes from time to time. We had a direct connected flywheel without an over running clutch. We measured flywheel rpm only. The magnetic sensor was sometimes erratic at the higher rpms. A Hall effect sensor might have been better. I usually imported the data into an Excel spreadsheet and averaged three identical runs to help average out run to run variations.

Lohring Miller

This is kind of what I was expecting to hear given all the research I have done so far;

Essentially, if you want the information gained from your dyno sessions to be "useful" in actual practice; the "length of pull" on the dyno should match as closely as possible the "length of pull" the engine will ACTUALLY SEE when you use it for its intended function.

So; the engines I am working on only have one use in mind:

Road Racing on small Kart tracks in single speed/ direct-drive configuration with a manually operated standard multi-plate motorcycle clutch. (no cetrifugal clutch)

From all of the 'thinking I have been doing, I think I have 2x(at least) "length of pull" metrics that I will be interested in looking at on my dyno.

Pull Standard 1: length of pull should be equal to the the 'average' acceleration time down the "long straight" at the Kart Track you are currently interested in tuning for.
-When tuning for tracks with a LONG straightaway, the pull length should be longer (and match the actual tracks straightaway accel time) than for tracks with SHORTER straightaways, where the accel time down the straight is -obviously- shorter.

Pull Standard 2: length of pull should be equal to the 'average' acceleration time between the exit of one corner and the entry of the immediately following corner (taken from data collected at the track).
-Thinking about this pull standard; it seems to me, for maximum tap time benefit, the slowest corner on the specific track you are currently tuning for that should be "exit corner"
-Improving acceleration time from the slowest corner exit to the immediately following next corner, as I understand it; will yield the greatest improvement in lap times from the metric of engine acceleration capacity.
-Even more gains can possibly be gained on a per-track basis by looking at acceleration times (and start/finish RPM's) for each set of corners. E.G. setting up dyno pulls that exactly match the exit of turn 3 into the entry of turn 4, in order to achieve a modification that ACTUALLY improves acceleration rate between some set of corners that you have identified as being "deficient" with your current power curve.

(clearly there are many other aspects of the bike that can be effectively tuned in order to yield significant improvements in lap times without any change to engine output , but when it comes to what can be gained from modifying the power curve of the engine, for my use case, the above is my understanding)

[ApolloMotoMoto]

Heya Wayne, this is Sean Davis from Facebook;

One the Wiseco pistons, I talked to my guy;

They havent sold any of those 11995M05900 pistons to the Asia guy in over 5 years, so it looks like they dont have 'right of refusal' for the transfer of the design.

If you want to work through me, I am totally willing to fascilitate the order through my Wiseco dealer account, my guy said thats just fine with them.

He would like your CAD file as a reference;

There are a few different part numbers the Asia guy had designed at the 59.00mm slug size, one with side-reliefs for some weight savings, for example...
-I told him you probably wouldn't want those, depending on where they are, because of the short circuiting from the aux exhaust port down to the A transfers, he was like, ahhh ok, yep understood.

The MOQ is going to be 12x
The price per piston at the 12x MOQ is going to be ~$150-160 depending on the final details like coatings and what is included with the piston itself (rings, wrist pin, c-clips).
The lead time is going to be ~12 weeks from the date we approve and sign the drawing from Wiseco.
(they will try and come in earlier than this, as they did for me, but that is the standard lead time)

I told him you essentially just need the skirt 3mm longer, and he said that wont be a problem, go ahead and send over the CAD file for reference and they will start working up a drawing for us to review.

[ApolloMotoMoto]

For reference, this is what Wiseco already has drawn up for the KR150 (attached)

[wobbly]

Looks like my comment about the code guy at Performance Trends being a Richard was prophetic.

He was convinced Frits Correction for Humidity was wrong and proceeded to convince himself and everybody else as to how and why.
Its the old story of he who is absolutely convinced of his infallibility , is probably wrong.
He had not transcribed Frits math correctly , exactly the same shit as happened initially with SportDevices.

So - rest easy guys , Frits is still knocking on the door for genius of the year , and my dyno file corrections are on the money.

[ApolloMotoMoto]

Looks like my comment about the code guy at Performance Trends being a Richard was prophetic.

He was convinced Frits Correction for Humidity was wrong and proceeded to convince himself and everybody else as to how and why.
Its the old story of he who is absolutely convinced of his infallibility , is probably wrong.
He had not transcribed Frits math correctly , exactly the same shit as happened initially with SportDevices.

So - rest easy guys , Frits is still knocking on the door for genius of the year , and my dyno file corrections are on the money.

Funny, my team got the same email, and I noticed the same mistake in their transposition of Frits code into their software;

Here is my reply:

Heya Kevin!

I reviewed the FOS Humidity Equation from the FOS .pdf document, and I compared it to what you have input into the DataMite software.

I am 99% sure I found the issue.
-The formula as entered into the DataMite software has one small typo, and does not exactly match the FOS formula!
-You have (...)C2*SGN(C2)*TAIRSTD^2 when it supposed to be (...)C2*SGN(TAIRSTD)*TAIRSTD^2


(The section containing the error is in BOLD on both formulas to make it easier to see)

FOS Formula:

C0=10.86703 : C1=.5 : C2= -0.025 : C3=1.202129E-03
PHUMSTD=HUMSTD/100*(C0+C1*TAIRSTD+C2*SGN(TAIRSTD)*TAIRSTD^2+C3*TAIRSTD^3)

DataMite Software Formula:

LocalWOTC0 = 10.86703: LocalWOTC1 = 0.5: LocalWOTC2 = -0.025: LocalWOTC3 = 0.001202129
PHumStd = HumStd / 100 * (LocalWOTC0 + LocalWOTC1 * TAirStd + LocalWOTC2 * Sgn(LocalWOTC2) * TAirStd ^ 2 + LocalWOTC3 * TAirStd ^ 3)


Here is another comparison with the notation in your formula adjusted to exactly match the FOS notation, making the error more clear:

(FOS Formula ON TOP of DataMite Formula)

PHUMSTD=HUMSTD/100*(C0+C1*TAIRSTD+C2*SGN(TAIRSTD)*TAIRSTD^2+C3*TAIRSTD^3)
PHUMSTD=HUMSTD/100*(C0+C1*TAIRSTD+C2*SGN(C2)*TAIRSTD^2+C3*TAIRSTD^3)



Please fix the formula typo and re-check the results!

Thank you!



-Sean

[_____]

In practice, you don't always need to remove all the water but only bring the relative humidity to the desired value. Sometimes you have to remove water to do that, sometimes you even have to add it.

I didn't know about a MAP sensor that measures temp, pressure and humidity. Do you have any further information on that?

Ok, do you know by heart what the percentage of Water was the target?

Regarding the sensors:
https://www.te.com/en/product-HPP815A533.html
https://www.te.com/en/product-CAT-HSA0004.html
https://www.amphenol-sensors.com/en/...ination-sensor

[wobbly]

Those sensors are not MAP as that specifically refers to Manifold Absolute Pressure.
Virtually all modern cars use a MAP and or a hot wire MAF and the fueling tables run off that manifold pressure or the mass of air being transferred into the manifold.
The one shown that does all 3 metrics to be able to generate RAD is pretty trick , and would be great to drive a weather adjusted fuel map , but as it stands that simply is not needed
as MAP and or MAF with IAT and Water Temp works perfectly in practice.

[Frits Overmars]

the engines I am working on only have one use in mind: Road Racing on small Kart tracks in single speed/ direct-drive configuration with a manually operated standard multi-plate motorcycle clutch. (no centrifugal clutch).
I think I have 2x(at least) "length of pull" metrics that I will be interested in looking at on my dyno.
Pull Standard 1: length of pull should be equal to the the 'average' acceleration time down the "long straight".
Pull Standard 2: length of pull should be equal to the 'average' acceleration time between the exit of one corner and the entry of the immediately following corner.
-Thinking about this pull standard, for maximum lap time benefit, the slowest corner on the specific track you are currently tuning for that should be "exit corner"

Don't put too much value on your Pull Standard 1.
Direct-drive engines are a special case. When I first encountered such an engine, I thought it was horrible and I was convinced I could do better.
The first thing I did was make a new exhaust pipe with a much narrower, tapered header. Now 'my' kart could overtake two or three competitors every time on the main straight.
Small problem: it would be overtaken by two or three competitors at every corner exit. And all circuits have more corners than straights...

[Frits Overmars]

Looks like my comment about the code guy at Performance Trends being a Richard was prophetic. He was convinced Frits Correction for Humidity was wrong and proceeded to convince himself and everybody else as to how and why.
Its the old story of he who is absolutely convinced of his infallibility , is probably wrong. He had not transcribed Frits math correctly , exactly the same shit as happened initially with SportDevices.
So - rest easy guys , Frits is still knocking on the door for genius of the year , and my dyno file corrections are on the money.

So I'm still on my way to eternal fame. Oh well, I suppose it beats knockin' on heaven's door https://www.youtube.com/shorts/D-y3ry54Q9I

[ApolloMotoMoto]

So I'm still on my way to eternal fame.

Fire burning within the ice from "Eternal Flame Falls" in Chestnut Ridge Park, New York.

"This flame is visible nearly year round, although it can be extinguished and must occasionally be re-lit."



...must occasionally be re-lit.

[jonny quest]

I saw Wobblys pic of the KR carb arrangement. No room, so it's pointing down towards crank.

It got me thinking. So much flow goes to A ports naturally.

What if the B port started at wall closest to EX port, crosses over in ducts. A duct entry started where B Normally is.

I understand there will be a lot of energy lost in this weird tunnel configuration.

My other reasoning for this, when A exits are left with no chamfers, and there's some room between A exits and EX port... the engine has a much more crisp feeling. It's much easier to jet, you don't have that lag and temperamental nature with short circuiting.

There's a lot of connectivity between A and EX. This criss cross layout may outweigh the current obstacles, even though it will present it's own?

[wobbly]

The carb setup on the KR180 drag engine is done that way to get the intake dead straight and more importantly to get the the exact tuned length
from reed tips to the bellmouth + end correction.
That SPJ carb will have the intake filter adapter removed , if I use it instead of a 40mm Lectron HV.
The Intake Trace shows the intake wave bouncing of atmosphere going + pressure ratio at the same time the case goes negative.
This pressure differential on both sides of the reed petals opens them quicker and higher, and works over about a 2000 rpm span.

[Vannik]

I saw Wobblys pic of the KR carb arrangement. No room, so it's pointing down towards crank.

It got me thinking. So much flow goes to A ports naturally.

What if the B port started at wall closest to EX port, crosses over in ducts.

Why do you assume the flow goes naturally to the A-port. As the piston goes up the flow naturally goes into the cavity the piston movement creates. As the pressure in the transfer ducts are also higher than the pressure in this cavity, there is also flow from the transfer ducts into this cavity. This is why you want to aim the reed block pointing into this cavity. Unfortunately transmissions usually get in the way as it is even more important to get the inlet duct straight.

Now from the above explanation it should also be clear that Boyesen ports do not aid flow to the B-port but add extra area to the piston controlled part of a cylinder reed. Strange how many still miss this.

[TZ350]

.


Maybe not as flash as some but two working examples of Kiwi home brew dynos and the ESE boys figuring out how to use a secondhand Dynojet. Nothing too expensive here, but they all do the job.