Feature request: Tool to calculate lambda delay.

For discussion of Phil Tobin's Tuner Studio software (Only about the tuning software itself, not about how to tune or firmware features)

Moderator: LT401Vette

piledriver
Super MS/Extra'er
Posts: 1679
Joined: Tue Oct 27, 2009 6:24 am
Location: Van Alstyne, Texas

Feature request: Tool to calculate lambda delay.

Post by piledriver »

It's been talked about as a test mode in the firmware, but it really belongs in Tunerstudio, as VEAL works AWESOME when the delay table is ~correct. A tool to do it automagically would cut tuning time dramatically in many cases.

Preferably user would just enable/disable for a short period as it would probably cause hiccups in normal running, and its not likely to change much unless the motor/exhaust/WBO2 changes drastically.

Plus, it would be a good baseline for the MS3 LTT lambda delay table.
(You could even stuff the results there, at least on MS3s)

Getting the data is probably a bit daunting for new users, even though its not really that hard to do.
(Its also not really documented that you might even need to do it, or how, anywhere)

The default values makes VEAL not work as awesome as it can on anything with long tube headers, at least...
When the delay table is sane, it works almost like magic.
Always doing things the hard way, MS2 sequential w/ v1.01 mainboard, LS2 coils. 80 mile/day commuter status.
LT401Vette
Super MS/Extra'er
Posts: 12697
Joined: Sat Jul 16, 2005 8:07 am
Location: Moorseville, NC
Contact:

Re: Feature request: Tool to calculate lambda delay.

Post by LT401Vette »

That has been on the todo list for years, I would think it should finally make it into the next major release.
Phil Tobin
EFI Analytics, helping to simplify EFI
Next Generation tuning software.
Supporting all MegaSquirt versions and firmwares.
http://www.TunerStudio.com
http://www.efiAnalytics.com/MegaLogViewer/
Support the firmware running your engine:
http://www.msextra.com/doc/donations.html
jesse408
Experienced MS/Extra'er
Posts: 178
Joined: Tue May 14, 2013 6:30 am

Re: Feature request: Tool to calculate lambda delay.

Post by jesse408 »

Lambda Delay Table generator could be VERY helpful. :D
Marek
Master MS/Extra'er
Posts: 573
Joined: Sun May 10, 2009 1:20 am
Location: Guildford UK

Re: Feature request: Tool to calculate lambda delay.

Post by Marek »

Would it be possible to use the delay table to generate an "undelayed AFR" output in the datalogs, assuming the datalog is written to with a short time delay?

It'd be so much easier to look at a datalog where AFRs and AFRtargets superimposed properly. In fact, if you could have the option to simply plot the undelayed AFR as a default in MLV, then you could alter the table and check the fit visually.

kind regards
Marek
piledriver
Super MS/Extra'er
Posts: 1679
Joined: Tue Oct 27, 2009 6:24 am
Location: Van Alstyne, Texas

Re: Feature request: Tool to calculate lambda delay.

Post by piledriver »

AFAIK that is currently the case for logging, and would almost certainly remain so.
The delay time is only really needed when making corrections, so you are correcting the proper cells with the corresponding data.
Always doing things the hard way, MS2 sequential w/ v1.01 mainboard, LS2 coils. 80 mile/day commuter status.
whittlebeast
Super MS/Extra'er
Posts: 2221
Joined: Tue May 04, 2004 8:20 pm
Location: St Louis
Contact:

Re: Feature request: Tool to calculate lambda delay.

Post by whittlebeast »

I wonder if we could with some sort of test mode. Picture having a TS Button that adds say 15% fuel instantly for say .75 sec. This would be abut 2 AFRs. We could have a Status code for this that sets for this .75 sec. Then just watch the AFR as reported by the O2s. You could do this at several air flows and get the Lambda delay with very little real effort. All we need is a button in the SW and look at the data.

Andy
Paul_VR6
Super MS/Extra'er
Posts: 1978
Joined: Wed Apr 15, 2009 11:31 am
Location: Oxford, PA
Contact:

Re: Feature request: Tool to calculate lambda delay.

Post by Paul_VR6 »

I always just set the rev limiter (fuel cut) to a few different rpms and then hit them at a few different map values. Some engines are fairly stable some change a bit across that range.
-Paul
1992 Corrado SLC 3.6 VR6 11.38@120 - MS3 Pro Ultimate - Microsquirt I/O - Can EGT - Racepak IQ3s
kptuned.com - Megasquirting the World! Megasquirt Sales, Service, Tuning and More!
Image
panel
Master MS/Extra'er
Posts: 663
Joined: Tue Aug 17, 2004 9:56 pm
Location: Victoria B.C. Canada
Contact:

Re: Feature request: Tool to calculate lambda delay.

Post by panel »

Could someone ( Andy or Paul or whoever ) post a pic of what newbies should be looking at to help make our table up ?
Like some arrows pointing at the time and where it drops off etc. Maybe an original table and what a new table should look like after viewing the log.
'65 VW Bus with a Subaru EJ20 Turbo conversion , Air to water I/C , LS coils , 14Point7 Spartan 2 & Solid Air Fuel Ratio 52mm gauge.
MS2 Extra V3.0 board
andy198712
Experienced MS/Extra'er
Posts: 172
Joined: Sat Aug 06, 2011 12:47 pm

Re: Feature request: Tool to calculate lambda delay.

Post by andy198712 »

Hi,

Has this been made a feature yet? i was just thinking about it.

the fuel cut idea is a good one, its something i've always thought i need to trial but havnt actually done it yet (shamefully)
LT401Vette
Super MS/Extra'er
Posts: 12697
Joined: Sat Jul 16, 2005 8:07 am
Location: Moorseville, NC
Contact:

Re: Feature request: Tool to calculate lambda delay.

Post by LT401Vette »

It was being worked on for 3.1, but there were complications so could not be put in yet.
Phil Tobin
EFI Analytics, helping to simplify EFI
Next Generation tuning software.
Supporting all MegaSquirt versions and firmwares.
http://www.TunerStudio.com
http://www.efiAnalytics.com/MegaLogViewer/
Support the firmware running your engine:
http://www.msextra.com/doc/donations.html
andy198712
Experienced MS/Extra'er
Posts: 172
Joined: Sat Aug 06, 2011 12:47 pm

Re: Feature request: Tool to calculate lambda delay.

Post by andy198712 »

LT401Vette wrote:It was being worked on for 3.1, but there were complications so could not be put in yet.

Okay cool :) i can't imagine its a simple thing to write!!
Reckon it'll be in a future update or had to drop it?

Thanks
Andy
Malic
Helpful MS/Extra'er
Posts: 69
Joined: Sat Mar 07, 2020 5:29 pm

Re: Feature request: Tool to calculate lambda delay.

Post by Malic »

Am looking forward to this feature, as I seem to be having the issue myself where it is either pulling too much fuel or going to rich because the delays are off and I cannot figure out them, have been trying to set up fuel cuts, fuel dumps, all trying to figure out combustion to O2 sensor delays, and every change just seems to make things worse.
Malic
Helpful MS/Extra'er
Posts: 69
Joined: Sat Mar 07, 2020 5:29 pm

Re: Feature request: Tool to calculate lambda delay.

Post by Malic »

Does their happen to be a beta version to try what there is?

I have been trying to do everything I can to figure out these values (switch between normal map and a map of all 0's, or an extremely rich map, and cannot figure out any numbers that makes sense.

Have some points at ldle that seem to react in 2000 ms, other times in 70ms, switched back to the default delay that TS comes with, etc

Have a feeling that because it is always looking at the wrong delay data, is why the car is always bucking off the line with 15-16:1 afr, and then when manually add in more fuel for a lean condtion, then it wants to correct and add in a ton more fuel and then am sitting at 9:1 afr
piledriver
Super MS/Extra'er
Posts: 1679
Joined: Tue Oct 27, 2009 6:24 am
Location: Van Alstyne, Texas

Re: Feature request: Tool to calculate lambda delay.

Post by piledriver »

Back when I was playing with the tune regularly, repeatedly saw that turning off all the advanced stuff than accel options that rely on the ve table while creating the ve table speeds things up and reduces headaches. I have also heard it doesn't matter, but it sure seems to.

if your engine has the sensor in short cast iron manifolds like a stock gm v8 or such, the default delays are probably reasonable, although the wbo2 controller has a big effect delay wise--- ms3 seemed at one point to also have a longer delay vs ms2e even using same engine sensor/wbo2 controller etc.

If you have long tube headers or your sensors are some distance from the exhaust valve back by the cat, its going to be much different.

best i can offer is start with a man on base...
hopefully a code block will preserve formatting... this is what seems to work very well on my engine.
you can just hit the corners and scale between them... and pick the rpm/load range that you use.

Code: Select all

97 290 202 125
60 776 540 332
30 1170 814 500
I have a long tube tri-y header on an aircooled vw., sensor in the collector, about 900mm away from valve, running an ancient (but very fast reacting) JAW 1.03 wideband... ymmv a lot.

MS3 had a much higher resolution delay table, in the ecu, but I think its meant to be learned, havent looked at the code, not certain its even used.
Always doing things the hard way, MS2 sequential w/ v1.01 mainboard, LS2 coils. 80 mile/day commuter status.
piledriver
Super MS/Extra'er
Posts: 1679
Joined: Tue Oct 27, 2009 6:24 am
Location: Van Alstyne, Texas

Re: Feature request: Tool to calculate lambda delay.

Post by piledriver »

The easiest way to do it currently is using a second ve table set leaner or richer and using an input to table switch...
. ..ideally when doing high speed sdcard logging. I was sampling at ~400hz at one point with a fast class 10 card.


The delay each way (fuel leaner or richer) may differ.
Always doing things the hard way, MS2 sequential w/ v1.01 mainboard, LS2 coils. 80 mile/day commuter status.
Paul_VR6
Super MS/Extra'er
Posts: 1978
Joined: Wed Apr 15, 2009 11:31 am
Location: Oxford, PA
Contact:

Re: Feature request: Tool to calculate lambda delay.

Post by Paul_VR6 »

I generally use the rev limiter, set to fuel cut and set to various rpm breaks and try and hit at a few map values. Then you just need to look at the logs. The fuel cut gives a nice sharp edge for the delays.
-Paul
1992 Corrado SLC 3.6 VR6 11.38@120 - MS3 Pro Ultimate - Microsquirt I/O - Can EGT - Racepak IQ3s
kptuned.com - Megasquirting the World! Megasquirt Sales, Service, Tuning and More!
Image
Malic
Helpful MS/Extra'er
Posts: 69
Joined: Sat Mar 07, 2020 5:29 pm

Re: Feature request: Tool to calculate lambda delay.

Post by Malic »

am I looking for the moment there appears to be a change, or a certain value?
Paul_VR6
Super MS/Extra'er
Posts: 1978
Joined: Wed Apr 15, 2009 11:31 am
Location: Oxford, PA
Contact:

Re: Feature request: Tool to calculate lambda delay.

Post by Paul_VR6 »

More or less afr will peg full lean as the fuel cut comes through. Difference between time when that happens and when pw is 0 is the delay.
-Paul
1992 Corrado SLC 3.6 VR6 11.38@120 - MS3 Pro Ultimate - Microsquirt I/O - Can EGT - Racepak IQ3s
kptuned.com - Megasquirting the World! Megasquirt Sales, Service, Tuning and More!
Image
Malic
Helpful MS/Extra'er
Posts: 69
Joined: Sat Mar 07, 2020 5:29 pm

Re: Feature request: Tool to calculate lambda delay.

Post by Malic »

This is why I am trying to get a better explanation as the description given of the method is very vague when it comes to looking at the datalog part.


I have a mountain road that I have been using to try to figure these values out, combined with a program called Voice Attack, that I have some inputs programmed into it. When I hit spacebar it starts, and when I hit spacebar a second time it stops. All it does is go between the two maps.

Have tried two methods
First is to switch to a map that has no fuel, then two second later, it goes back to standard map. This method sucks for trying to find high RPM because when it cuts, it cuts hard.
Second method is adding a bunch of fuel, two seconds later it removes the addition, this has side effect of you get two data points, one when adding, and one when returning, since the car is still able to run mostly normal while doing this

I have been using two seconds to just try to make the changes as separated on my datalog as I can.

If I am cruising at 14.7, and it cuts to 0 PW, (and here I ask the question again) am I looking for the moment there appears to be a change, or a certain value?

When it hits 16, 22, 14.8?

I dont get a sharp cut, it gradually goes to extreme lean.

On one cut at a specific MAP and RPM, it takes 500ms, on another it takes 3800ms, on another it takes 58ms. They jump around wildly

It is even more difficult the lower the RPM
piledriver
Super MS/Extra'er
Posts: 1679
Joined: Tue Oct 27, 2009 6:24 am
Location: Van Alstyne, Texas

Re: Feature request: Tool to calculate lambda delay.

Post by piledriver »

cutting spark it will show a very sharp cutoff...
perhaps set the wbo2 lag at 100?(no lag)
My preference would still be a switch to cut injector or coil power momentarily, as you dont have to fiddle your tune to get data.

The main thing to look for is the step change in afr value.
If it looks gradual do something different.
Always doing things the hard way, MS2 sequential w/ v1.01 mainboard, LS2 coils. 80 mile/day commuter status.
Post Reply