ESE's works engine tuner

[polinizei]

I run the turbulent model when defining the chamber with squish and comp and than put the data into the pre described table. Neels told me he modified the combustion part which changed the TUbMax and of course power. But as I have dyno curves of some of my projects which correlated very good I'm now getting definitively to low with the power estimate. Don't know how to fix that, went down with comp and combustion efficiency, but as said now being to low in the power estimate. Does anybody have a good idea for me what parameter to change?

try "combustion efficiency"

1 = 100%
0,94 = 94%
....

[41juergen]

I'm to high in TUbMax and corresponding to that too low in power estimate. I already went down from 0,87 to 0,85 for the stock 3XV engine (which has only 50 HP for a 250cc... ). I also had in an other project the comp from 15,5 down to 14,5. With the old version I didn't had the high TUbMax and the power showed the same data I got from dyno pulls...
Am I right that when using the pre-described model filled with the vibe parameters from the turbulent model the TUbMax result will be the same as when using the turbulent model (all other parameters still the same)?

[teriks]

The latest software has a new pipe heat release model incorporated, and for a racebike like the NSR you should use rpm driven pipe temp.
325*C at the start of the powerband and 425*C at peak power, say 8000 and 12,000.
If using a solenoid powerjet then this is modeled best by going to 450* in the overev.

Would this pipe temperature setup be correct for a more or less static rpm application?
Methink it is (partly at least) needed because of shifting and accelerating thru the rpm range, and that for static rpm the variation would be at least smaller?

[wobbly]

If TuB is too high and you get screen deto, then the only parameters to kill this are - Timing, Compression and Stinger Size.
High MSV, over 40M/s will affect the combustion parameters and crank up TuB,but if you adjust this down,you have to then rerun Turbulent.
Yes, the imported numbers from a Turbulent run copied into a Burnrate file, will operate identically.

The pipe wall temp numbers give me the best correlation to many many AvGas dyno runs, and the % temp change from the bottom of the power band
into the overev is the same change as is seen in the EGT when doing a single gear heavily loaded DynoJet pull.
I really dont see any point in constant rpm power readings,I try my best to load the engine on the dyno to replicate the acceleration rate as seen on track.
This is easy with a DynoJet 160 that has a programmed in variable load control, that increase with wheel speed,as does aero on track.

[teriks]

The pipe wall temp numbers give me the best correlation to many many AvGas dyno runs, and the % temp change from the bottom of the power band
into the overev is the same change as is seen in the EGT when doing a single gear heavily loaded DynoJet pull.

Well a really heavy load would be quite close to static RPM id guess.

I really dont see any point in constant rpm power readings,I try my best to load the engine on the dyno to replicate the acceleration rate as seen on track.

Me neither, for engines intended for road use that is. Though my application is "Survive 5-10 seconds heavy load before ~10-15 seconds of acceleration and a rise in rpm of some 3-4kRPM, followed by 45-55 seconds of more or less constant rpm, maybe some 1krpm variation around 33krpm". Add to that that the first few seconds is at zero airspeed, and the last ~50s is at some 350km/h witch should have some unwanted effect on pipe cooling.

Guess this parameter too applies for another of those (not so)educated guesses, or better yet, an egt logger. The power curve looks much more appealing when I apply the rpm dependent wall temp though.

[emess]

the imported numbers from a Turbulent run copied into a Burnrate file, will operate identically.

That was always true for me with previous versions of Engmod, but not with the latest version, 5.2.5

Comparing a Turbulent run to Prescribed using imported values from the Turbulent run, I get significantly different results with v5.2.5.

Turbulent runs show Max power down 2hp in 36 over the prescribed run and TUbMax differs by 35° or more. (This sounds similar to 41juergens post 22303 on the previous page.)

In older versions the delay times in exported cmb files were suspiciously similar at different rpm, almost always ending in .99 and mostly changing by whole units. In the new version, delay values from a turbulent run differ at each rpm and vary smoothly which seems more realistic so the new version looks better (for me at least) as long as I always run the Turbulent model.

Mick

[marsheng]

I am currently installing a four channel data logger on my new bike, an aircooled 125cc 2T. It will be the first time I have collected any real temperature data, I hope I can get it to work properly because it will be very interesting to see what happens with the air cooled motor and how much we can improve the cooling with ducting.

I have a 4 channel gpxpro. It is fantastic. It just works. Recently I seized my maico and looking at the cht I can see it increasing on the last lap before the sudden stop.


This one is for the engineers.

How do you frustrate an engineer beyond all reason? Tie him to a pole and then fold up a road map the wrong way!

[AndreasL]

Trying some new turbulent runs after the update.

DETO as hell!

Does any one have a clue about what TuBmax is safe for unleaded 95 from the pump?
Or any other unleaded that might give me a clue.
Now it seems lika >860°C and we have deto.

May be a stupid question, but is a run full of "deto" as good to use when generating the turbulent file or is it essential that the sim is detofree?

EDIT: Upps, the stinger was still down at 8mm... New run it is.

[41juergen]

Some should better listen to the hints of the wise ones...
So after running the turbulent model (also with deto's as hell) and putting the data into the pre-described table everything is good again. For any reasons the TUbMax goes back down to the numbers seen before, also power goes up again similar to what I had before. There is a difference between the two models running the same Vibe input data. Running all sims with the turbulent model is not the right way to do.

So follow the advise of Wob and Neels how to proceed and everything is good again....
Thank's Wob!

Regarding the pipe wall temps: if going with 100 octane pump gas with slightly richer in AFR shall the wall temps also be reduced a bit, let's say to 315°C for the start, 415°C for peak and 440°C for the overrev area?

[ief]

How many percent of Neels his userbase is actualy knowing what they are doing? Guess that won't be to much (?) Meaning my guess would be 'fudging' is more common then not whitch is a shame of the program but allmost unavoidable. How to tackle that? Would there be way's for Neels to make it more foolproof and if so, how?

Opted for a userforum a long time ago but that won't happen I guess...

Just thinking out loud.

[adegnes]

Some should better listen to the hints of the wise ones...
So after running the turbulent model (also with deto's as hell) and putting the data into the pre-described table everything is good again. For any reasons the TUbMax goes back down to the numbers seen before, also power goes up again similar to what I had before. There is a difference between the two models running the same Vibe input data. Running all sims with the turbulent model is not the right way to do.

So follow the advise of Wob and Neels how to proceed and everything is good again....
Thank's Wob!

Regarding the pipe wall temps: if going with 100 octane pump gas with slightly richer in AFR shall the wall temps also be reduced a bit, let's say to 315°C for the start, 415°C for peak and 440°C for the overrev area?

I see no problem with running turbulent all the time, if you don't mind the relative slowness.
Edit: wait what? You saw massive detonation when running turbulent, but none when running the generated combustion file in prescribed mode?

Re temps; here's what I did:
1050f egt unleaded is 16% < 1250f egt avgas
325 - 16% = 273
425 - 16% = 357

Might be totally wrong, but makes sense to me.

[AndreasL]

Edit: wait what? You saw massive detonation when running turbulent, but none when running the generated combustion file in prescribed mode?

Me to.
Don't really now what to trust or what TuBmax to consider safe for my unleaded pumpgas.

[ief]

Isn't it so that turbulent uses none (or only ignition curve????) of the input from the combustion file, thus giving deto way easier? Then it calculates the vibes and stuff and you use those figures the next run, no more deto.

That make sense?

[adegnes]

This is the exact same model run in turbulent vs prescribed with a combustion file I got from another turbulent run.
Weird.

[adegnes]

Isn't it so that turbulent uses none (or only ignition curve????) of the input from the combustion file, thus giving deto way easier? Then it calculates the vibes and stuff and you use those figures the next run, no more deto.

That make sense?

Turbulent uses entered ignition timing and afr.