ESE's works engine tuner

[TZ350]

How big was your bored out OKO?

24mm OKO was bored out to 28mm. It carbureted Ok. But when I tried this trick using bigger carbs like 38's there was an immediate flat spot if I whipped the throttle wide open quickly. Not very useful, but not a problem with the OKO.

[yatasaki]

Ups...even hpi is not without damages...

The 210 series with light...outside rotor collapsed with new inner stator on our enduro at coil for timing...ääh...fuck...2 dissapointing races in 2 weeks ... ficken !



Please...give us answer which parts in special...which ignition went to disaster... and why ...sorry...not clear to me...

Try to avoid every Desaster in long lasting races

Thanks

Wolfgang

Sorry I typed to purchase hpi or selletra instead of PVL or selletra.
HPI 068k012& k017 in particular

[aljaxon]

i am needing a bit of an explanation of what starts to happen at the point where the belly changes into the rear or baffle cone.

to my thinking this is when the stuffing waves start returning to the cylinder. lets say tuned length is 9000rpm so these "start" waves at 9000rpm will be returning well before ex port closing. and they will return at ec well over the peak 9000 lets just say 12000rpm. could be a lot higher but its not the point.

and how do i get the "start waves" to not return so high rpm or so early at 9000rpm . my logic is to have a longer belly. but to retain the tuned length then the rear cone gets a sharper angle. and at some point too sharp is no good.

there is something im obviously missing. or is the rear cone just a compromise? in the old days thinking was that the rear cones midpoint was the tuned length so you had a bit of cone before and after to give you decent waves either side of peak power. but having the end of the cone for the tuned length there doesnt seem to be any cone physically to give you decent waves below peak rpm.

apologies for being a retard




.

[Wos]

Sorry I typed to purchase hpi or selletra instead of PVL or selletra.
HPI 068k012& k017 in particular

Ok yatasaki

Owner of hpi told us to outer rotor...there are problems with overheating when they are covered.
And he told...inner rotor hpi should be more ressistant to heat...

But what the hell we could do in enduro with water and mud...for 6 hours

Now installed hpi inner rotor...and the rider told...significant mor power as never before...same ignition timing...
Ok...that was at last race this year...lets see next year

Wobbly!

Thanks...thaught about a solution with old crosser ignitions...that coils seem to be undestroiable


And for newer Generation of crossers there are plug and Play programmables from hpi we are very happy with...squish...carb and map and you are in ballpark of factory bikes


Grüße Wolfgang to all

[wobbly]

Luckily the explanation is simple , so any retard can get it.
Yes the rear cone used to be a compromise , with a single angle the mid point of the full uncut conic is the mean reflection point.
Not that that was any help to anyone , but that's the physics involved.

But if you want to reduce the reflection amplitude whilst the piston is dropping , or around BDC . then its a simple matter of reducing the cone angle.
Then later , as the piston is rising , reducing the port area , we can now increase the cones efficiency by increasing its angle - as the pipe surface furthest away is effective later and later in the waves
time signature.
Take this to the logical extreme and you get parabolic curved shape .
This was first used mid last century in clever designs , made of spun sheet metal , used in KT100 clutch pipes - way way before some clever dick thought to use the simpler multi angle approach.

Nowdays we can easily approximate the parabolic shape , with a 3 angle rear , and test first a single angle to confirm the TL , then beat the hell out of that in EngMod with three angles.
In that painful iterative process you can very accurately adjust the peak , and drop off angle after peak power , by the length and angle of the last steepest section.
The length and angle of the first two sections sets the ramp up shape of the front side power potential.

In this design I did for TM , I spent 3 months looking for the best combination of front side ramp and slow overev angle - made excruciatingly hard due to no PV and a straight line ignition.

[Frits Overmars]

what starts to happen at the point where the belly changes into the rear or baffle cone.
to my thinking this is when the stuffing waves start returning to the cylinder. lets say tuned length is 9000rpm so these "start" waves at 9000rpm will be returning well before ex port closing.

Yes, hopefully. Otherwise the waves couldn't do much good, could they?

then... the rear cone gets a sharper angle. and at some point too sharp is no good.

You've got that right, Al.

in the old days thinking was that the rear cones midpoint was the tuned length...

In the old days thinking was also that the earth was flat. Every change in cross flow area causes a reflection, that is to say: over the entire length of the cone. The fact that in those old days people assumed the wave to start from the center of the cone, or, even more daft, from the middle of the total length of the imaginary end cone extended to zero diameter, was just an aid to form a mental picture (pun intended).

[skako]

Hello everyone,

several ignition timing simulations. Model C9 has variable time. Model C21 has a fixed time of 22° which can be seen in the attached pictures.
Model C9 and C21 at 9000 RPM have the same ignition time. All other model settings are the same for all models shown.
It is not clear to me, at 9000 RPM both models should have the same power.
The power graph would have to overlap or intersect each other at 9000 RPM? That's not the case here?
Maybe I didn't set the model right?
Can someone clarify this for me?

[wobbly]

Haha Frits , the only mental picture I get from you saying " aid " is marital.

[wobbly]

Skako, the sim is calculating the pipe bulk temp in real time as the rpm points progress.
It cannot suddenly change the accumulated results at one specific rpm , unless you only run that one rpm individually and overlay the two results.
Thus what was happening directly before 9000 is affecting that result - just as would happen in reality.
Neels may have a better logic than mine here.

Two things to note - its absolutely impossible to run 95 Unleaded at 13:1 , I use 11.75 A/F ratio and that's pushing it hard.
Even 110 Octane would struggle to not detonate at 13:1 when making serious power.

Also you have not run the sim in Turbulent mode , then created a new Combustion Model from that run , with the real Delay/Duration and Vbe numbers that are affected by Compression/MSV/ timing and A/F etc
specific to your setup.
You enter the new saved Combustion file parameters , and then continue in Prescribed - its also way faster.
Just running the generic inputs can lead you well down a blind rabbit hole of non reality - again.

EDIT - running 22* of advance at peak power the thing will absolutely destroy itself , so something else is seriously wrong for the screen to not be screaming DETONATION at you during a sim run.

[F5 Dave]

In the old days thinking was also that the earth was flat. . .

Well I don't want to spoil Christmas for anyone
But Santa isn't real
. . . either is Jesus.

[TZ350]

.

Well I don't want to spoil Christmas for anyone but Santa isn't real.

but the Xmas Elf is real... right!

[husaberg]

.



but the Xmas Elf is real... right!

why yes....

[Wos]

Hello everyone,

several ignition timing simulations. Model C9 has variable time. Model C21 has a fixed time of 22° which can be seen in the attached pictures.
Model C9 and C21 at 9000 RPM have the same ignition time. All other model settings are the same for all models shown.
It is not clear to me, at 9000 RPM both models should have the same power.
The power graph would have to overlap or intersect each other at 9000 RPM? That's not the case here?
Maybe I didn't set the model right?
Can someone clarify this for me?

My personal picture is that all involved parts...cylinder, piston, head and pipe act as a storage of heat that was produced by all the parameters of combustion...so a change of ignition timing never can result in a complete sudden change of egt temperature... like maybe wanted...expected...predicted

So in a optimum ignition timing for specific arrangement, especially pipe....there has always to be a delay, for heating up or cooling down the egt...???

Am i right...or wrong? specialists here???

[skako]

I was thinking of testing with an electric Prony brake, where power (torque) can be accurately determined at constant RPM.
An accurate electric Prony can hold a loaded engine for 5+ minutes at exactly 9000 RPM. Then the influence of too hot or too cold exhaust pipe is no longer there. The gas mass flow is uniform throughout the entire engine with all gas dynamics within the exhaust pipe.
Why I mention Prony. Prony is a static brake at a constant RPM, while the Dyno test has to measure it in 1-2 seconds when the RPMs have already escaped to higher where we have new conditions.
If at a constant RPM the input parameters are the same, then the output result should be the same for all..
With due respect all, I think Vannik sees something more.

[aljaxon]

Luckily the explanation is simple , so any retard can get it.
Yes the rear cone used to be a compromise , with a single angle the mid point of the full uncut conic is the mean reflection point.
Not that that was any help to anyone , but that's the physics involved.

But if you want to reduce the reflection amplitude whilst the piston is dropping , or around BDC . then its a simple matter of reducing the cone angle.
Then later , as the piston is rising , reducing the port area , we can now increase the cones efficiency by increasing its angle - as the pipe surface furthest away is effective later and later in the waves
time signature.
Take this to the logical extreme and you get parabolic curved shape .
This was first used mid last century in clever designs , made of spun sheet metal , used in KT100 clutch pipes - way way before some clever dick thought to use the simpler multi angle approach.

Nowdays we can easily approximate the parabolic shape , with a 3 angle rear , and test first a single angle to confirm the TL , then beat the hell out of that in EngMod with three angles.
In that painful iterative process you can very accurately adjust the peak , and drop off angle after peak power , by the length and angle of the last steepest section.
The length and angle of the first two sections sets the ramp up shape of the front side power potential.

In this design I did for TM , I spent 3 months looking for the best combination of front side ramp and slow overev angle - made excruciatingly hard due to no PV and a straight line ignition.

thanks for that wobbly. i got almost all of that. I saw that R1 pipe design on here when i did a big search. it uses much shorter header and end of diffuser percentages than the 32 68 that i am using for the current front end pipe design
i suppose i can make a pipe with a straight rear cone and then a couple with different angled parabola's and dyno them and go from there. ive always done a single angle rear cone and split it for ease of fabrication. having 3 different cones will make rolling them much simpler, and im no longer scared of welding. before i used to shy away from it and tried to avoid extra seams/joints.