HarleyTechTalk

Sarhan

The hump in the top right of both of the MAPxRPM vs DC appears to be a bust in the tune.

I would like to see o2v in the log to figure where the error is.  Having a wideband in the log would be very helpful if that is possible.

Andy

Could somebody pase list mlv hd formulas that they use. I understand that i will need to name them as they are named with logger im using which is a twin scan. Im lost when it comes to figuring how to write the formulas. Read the instructions off of mlv hd site nut cant make sense of it. Duty cycle ft and rear,afr out of range,ect...   thank you in advance!!!!

Quote from: 1stop on September 24, 2015, 07:18:22 AM
Ive got a question about data logging. Im currently using a twin scan logwoto ger. The twin scan two has limited data in the log. I was gave a power vision. I looked into the auto tune for it and there are a few to choose from. What is the difference in them? Im using mlv hd to veiw logs which is why i posted here.

Did you realize you can you can log data in one system and apply the corrections you find to whatever tuning software you want?

see http://www.nbs-stl.com/MLVDemo/100%20Scatter%20vs%20Histogram.png

On this screen shot you can see the scatter plot on the left and the matching/resulting histogram on the right.  The RPM and break points can be grouped to match your tuning software break points.

Andy

Quote from: 1stop on September 24, 2015, 08:23:47 AM
Could somebody pase list mlv hd formulas that they use. I understand that i will need to name them as they are named with logger im using which is a twin scan. Im lost when it comes to figuring how to write the formulas. Read the instructions off of mlv hd site nut cant make sense of it. Duty cycle ft and rear,afr out of range,ect...   thank you in advance!!!!

See http://www.nbs-stl.com/MLVDemo/267%20Smoothing%20Formula.PNG

and the results of the formula

http://www.nbs-stl.com/MLVDemo/268%20Smoothing%20Formula%20Example.png

I think the guys at FuelMotoUSA may soon release a copy to the settings file that they typically use to view their Power Vision data.

If you post a data log so I can see what you are looking at for fields, I can try to help you out.


Here is an example how I generate MsPerEngineCycle

I define that field as    [RPM]=0?1:120000/[RPM]  Keep in mind that you read that as IF  ?  Then : Else


Then I use that field to generate Duty Cycle

and I define that as   [PulseWidth]*100/[MsPerEngineCycle]

Hope this helps

Andy

This is what near perfection looks like for fueling.

Speed density on the left

http://www.nbs-stl.com/HarleyTuning/HarleyNearFuelingPerfection.png

Throttle based tuning Alpha-N

http://www.nbs-stl.com/HarleyTuning/HarleyNearFuelingPerfectionAN.png

And Speed Density compared to Alpha-N

http://www.nbs-stl.com/HarleyTuning/HarleyNearFuelingPerfectionVE.png

Andy

This is what being on the edge everywhere with timing looks like.  Slight knock detection almost everywhere on a big log.  That is about 75 min of data.  I think I would have the owner remove about a degree of timing over the entire map and see if he can feel a difference.  Trying better fuel for a tank may also help him learn something about what the motor wants.

http://www.nbs-stl.com/HarleyTuning/HarleyNearIgnitionPerfection.png

Have fun tuning

Andy

Quote from: whittlebeast on September 24, 2015, 06:39:50 PM
This is what near perfection looks like for fueling.

Speed density on the left

http://www.nbs-stl.com/HarleyTuning/HarleyNearFuelingPerfection.png

Throttle based tuning Alpha-N

http://www.nbs-stl.com/HarleyTuning/HarleyNearFuelingPerfectionAN.png

And Speed Density compared to Alpha-N

http://www.nbs-stl.com/HarleyTuning/HarleyNearFuelingPerfectionVE.png

Andy

What transients are being filtered?

(abs([RPM] - [RPM-4]) > ([RPM] * 0.10) ) or (abs([TP] - [TP-4]) > 5 )  or (abs([MAP] - [MAP-4]) > ([MAP] * 0.15) ) 

Glen, here is the data that generated those plots.  The guy that did that tune did everything with a Powervision on the street with stock narrow bands and a TPS based Cal.

http://www.hdforums.com/forum/ignition-tuner-ecm-fuel-injection/1072255-pv-knock-counter-is-running-but-i-can-t-hear-any-pinging.html#post14425322

Andy

Here is a screen shot showing the value of big data logs.  This log happens to be right at 1 million data points.

http://www.nbs-stl.com/MLVDemo/930%20FZ1%20MAP%20vs%20RPM.png

Patterns on AFR busts jump right out at you.

Have fun tuning.

Andy

Here is a interesting formula for Max Allowable Injector Duty Cycle

100*((120000/[RPM])-3)/(120000/[RPM])

6000 RPM returns 85% Max DC  Note 85% is considered the standard answer all over the internet.  They never mention the 6000 RPM part.
12000 RPM returns 70% Max DC
15000 RPM  returns 62.5% Max DC

This allows for 3 ms of injector rest time.

The guys at Motec clued me in on this one.

"6000 RPM returns 85% Max DC  Note 85% is considered the standard answer all over the internet.  They never mention the 6000 RPM part."

This IS the accepted standard. Are you stating this is in error?
I've always successfully used 85% as a maximum rule of thumb @ max demand. There are exceptions (short bursts) that may be allowable for street usage yet not for racing (constant high load/rpm) purposes.
Bob

Bob,  "Google Injector Calculator".  I have never seen one that mentions RPM and includes RPM in the calculation.

Well now you have, or can if you want to.
Goggle just gave me a whole page of em,
For example:
http://www.stealth316.com/2-calc-idc.htm

or how about:
https://www.rbracing-rsr.com/calcinjpulse.html



Of course, as Hardtail mentioned:

Quote from: whittlebeast on September 28, 2015, 12:55:51 PM
Bob,  "Google Injector Calculator".  I have never seen one that mentions RPM and includes RPM in the calculation.

Well, since it is the MAX demand that counts, it really doesn't matter what the RPMs are at max demand...just need to stay below 80% or 85% depending on who you respect for their opinion.
Bob

Tsani

I tried the RBRacing one and it does not appear to use the RPM in the calc.  Once you get to a high enough RPM, you run out of time when you include the opening time, the closing time and time for the injector drivers to cool.

I first ran into this years ago when I was injecting an 8000 RPM two stroke.  I had to run 80 lb injectors to support 70 HP per cylinder.

Andy

Quote from: whittlebeast on September 28, 2015, 01:32:49 PM
...Once you get to a high enough RPM, you run out of time when you include the opening time, the closing time and time for the injector drivers to cool.
Andy

Does not apply to Harley engines, right?
Bob

As long as you keep the injectors big and the RPM down, this should not be an issue.  Start pushing a really big build that will pull some revs and 85% may start to be an issue.

Andy

Ignore this sort of thing doing 16000 RPM rice bike stuff and you can get burned quick at the 85% rule and typical injector calculators.

Quote from: whittlebeast on September 28, 2015, 01:52:17 PM
As long as you keep the injectors big and the RPM down, this should not be an issue.  Start pushing a really big build that will pull some revs and 85% may start to be an issue.

Andy

Yep, when we come across a Harley with 160 cubic inches that twists 11,000rpms we definitely will need to be vigilant with injector sizing and fuel pressure to support it...but that's not our world or reality.
Bob

I don't use the RB Racing one myself.
With the internet, a generic search is not always better.
I stick to the one on my computer. A tool in TTS.

Quote from: Tsani on September 28, 2015, 05:20:21 PM
I don't use the RB Racing one myself.
With the internet, a generic search is not always better.
I stick to the one on my computer. A tool in TTS.

The TTS calculator ignores almost everything critical.  Fuel pressure, opening time/closing time/dead time.....  Good luck with that.

Well, that and a bit of common sense has been working for me.
Sometimes you just need to trust tried and true knowledge.
Especially when it has been gained by yours or others mistakes.
Ya think Burt Monroe could model everything on a computer?

Quote from: whittlebeast on September 28, 2015, 05:36:07 PM

Quote from: Tsani on September 28, 2015, 05:20:21 PM
I don't use the RB Racing one myself.
With the internet, a generic search is not always better.
I stick to the one on my computer. A tool in TTS.

The TTS calculator ignores almost everything critical.  Fuel pressure, opening time/closing time/dead time.....  Good luck with that.

Lets keep it simple...because it is....
Simply put, duty cycle is the amount of time a fuel injector is energized or on during an engine cycle (intake, compression, combustion and exhaust).
Nothing more to it Andy.
Duty Cycle is a reference number to use as a tool to determine when a bigger (or smaller) injector is called for right Andy? No matter the extrainious on/off/dead time, we are talking relative time and do not need to muddy the water that ends up taking our eye off the ball.
For example you matter-of-factly mention the TTS calculator doesn't take into consideration pressure when calculating duty cycle.
Can you explain how duty cycle is affected by pressure?
Bet not,
Bob

Bob,  The time that a fuel injector is energized is Pulse Width

Duty Cycle is the percent of the 720 degrees of crank rotation that the fuel injector is energized. (assuming 4 stroke)

Here are a few of the calculators out there on the net.

http://fuelinjectorclinic.com/flow-calculator

http://www.rceng.com/technical.aspx?UserID=18803956&SessionID=yezGGk73j6w4ToNQiReC

https://www.rbracing-rsr.com/calcinjpulse.html