Acceleration Ignition correction

This is a forum for discussing the development and testing of alpha MS2/Extra code. Documentation
(Runs on MS2 and Microsquirt)

Moderators: jsmcortina, muythaibxr

ruzki
Helpful MS/Extra'er
Posts: 63
Joined: Thu Nov 01, 2007 1:06 pm
Location: Germany
Contact:

Acceleration Ignition correction

Post by ruzki »

last week i had the opportunity to work with an Ecumaster Emu.
This ECU has a feature that is called "Acc.Ignition", picture attached.
It is obvious that tuning of the acceleration behavior of highly responsive 4 cyl. Engines, is only possible with a feature such this !
Yes ! maybe, in a lot of cases bad acceleration behavior is a result of bad tuning, but this cannot be a reason to omit this feature.

So my question is why the do the developers do not want to implement this feature ?

Georg
1.JPG
Peter Florance
Super MS/Extra'er
Posts: 3653
Joined: Fri Apr 02, 2004 8:40 pm
Location: Virginia Beach, VA
Contact:

Re: Acceleration Ignition correction

Post by Peter Florance »

Why is it obvious that tuning 4 cylinder requires this?

All I see is a picture with no settings from zero.
Peter Florance
PF Tuning
81 BMW Euro 528i ESP Car
60-2 Wheel LS2 Coils, Low Z Inj
Co-Driver 1999 BMW E46 DSP car.
ruzki
Helpful MS/Extra'er
Posts: 63
Joined: Thu Nov 01, 2007 1:06 pm
Location: Germany
Contact:

Re: Acceleration Ignition correction

Post by ruzki »

Why is it obvious that tuning 4 cylinder requires this?

All I see is a picture with no settings from zero.
Peter !
Is this a serious question ? Do you expect an answer ?

Georg
Peter Florance
Super MS/Extra'er
Posts: 3653
Joined: Fri Apr 02, 2004 8:40 pm
Location: Virginia Beach, VA
Contact:

Re: Acceleration Ignition correction

Post by Peter Florance »

ruzki wrote:
Why is it obvious that tuning 4 cylinder requires this?

All I see is a picture with no settings from zero.
Peter !
Is this a serious question ? Do you expect an answer ?

Georg
I do.

This feature is requested from time to time, but usually with more evidence than you have provided.

Often people requesting this feature are using MAF for load, and it reacts too late for ignition timing when changing load.

Why is the need obvious?
Peter Florance
PF Tuning
81 BMW Euro 528i ESP Car
60-2 Wheel LS2 Coils, Low Z Inj
Co-Driver 1999 BMW E46 DSP car.
DaveEFI
Super MS/Extra'er
Posts: 4175
Joined: Sun Apr 15, 2012 12:55 am
Location: SW London, UK

Re: Acceleration Ignition correction

Post by DaveEFI »

I'm curious about what would be different against setting the timing figure based on RPM and MAP?
Rover SD1 3.5 EFI
MS2 V3
EDIS
Tech Edge O2
London UK.
ruzki
Helpful MS/Extra'er
Posts: 63
Joined: Thu Nov 01, 2007 1:06 pm
Location: Germany
Contact:

Re: Acceleration Ignition correction

Post by ruzki »

@ Peter
Why is the need obvious?
you have already answerd this question with this :
This feature is requested from time to time, but usually with more evidence than you have provided.
.. because people are requesting it !

@ DaveEFI
less torque during acceleration would be the effect
Peter Florance
Super MS/Extra'er
Posts: 3653
Joined: Fri Apr 02, 2004 8:40 pm
Location: Virginia Beach, VA
Contact:

Re: Acceleration Ignition correction

Post by Peter Florance »

I didn't say I agreed with the evidence.

It would have been better if you have shown settings in your screen shot
Peter Florance
PF Tuning
81 BMW Euro 528i ESP Car
60-2 Wheel LS2 Coils, Low Z Inj
Co-Driver 1999 BMW E46 DSP car.
jsmcortina
Site Admin
Posts: 39585
Joined: Mon May 03, 2004 1:34 am
Location: Birmingham, UK
Contact:

Re: Acceleration Ignition correction

Post by jsmcortina »

ruzki,
Plenty of people have requested plenty of silly things over the years.

Posting unsubstantiated requests helps nobody.

So, you want less torque?? Well take your foot off the throttle? Acceleration is by definition more torque/power than is required to maintain the current velocity.

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
Peter Florance
Super MS/Extra'er
Posts: 3653
Joined: Fri Apr 02, 2004 8:40 pm
Location: Virginia Beach, VA
Contact:

Re: Acceleration Ignition correction

Post by Peter Florance »

I'm not even sure that is Ecumasters intended use for that feature. I'll ask someone I know who uses that product.
Peter Florance
PF Tuning
81 BMW Euro 528i ESP Car
60-2 Wheel LS2 Coils, Low Z Inj
Co-Driver 1999 BMW E46 DSP car.
muythaibxr
Site Admin
Posts: 8228
Joined: Thu Oct 14, 2004 12:48 pm

Re: Acceleration Ignition correction

Post by muythaibxr »

The ECUs I have seen that need that feature need it because they do not use every tooth on their crank wheels to schedule timing, and don't have any prediction, so spark comes late on accel. We use every tooth and have prediction.
Megasquirt is not for use on pollution controlled vehicles. Any advice I give is for off road use only.
ruzki
Helpful MS/Extra'er
Posts: 63
Joined: Thu Nov 01, 2007 1:06 pm
Location: Germany
Contact:

Re: Acceleration Ignition correction

Post by ruzki »

Posting unsubstantiated requests helps nobody.
I want to make clear that i have not requested any feature ! Please read the first post
I got the impression that you people do not read anymore and jut switch on your "self-defense mode" .. but why ?
this post assures this
Plenty of people have requested plenty of silly things over the years.
Again the question was:
So my question is why the do the developers do not want to implement this feature ?
So, you want less torque?? Well take your foot off the throttle? Acceleration is by definition more torque/power than is required to maintain the current velocity.
Right !! and now tell this a woman :lol:
I´m talking about highly responsive engine´s, 70mm inner Diameter Throttle Body on an 2.0 4cyl. for example, i bet non of us can push the gas pedal gentle enough to maintain a smooth acceleration from very low velocity.
I'm not even sure that is Ecumasters intended use for that feature. I'll ask someone I know who uses that product.
ask me !
ruzki
Helpful MS/Extra'er
Posts: 63
Joined: Thu Nov 01, 2007 1:06 pm
Location: Germany
Contact:

Re: Acceleration Ignition correction

Post by ruzki »

The ECUs I have seen that need that feature need it because they do not use every tooth on their crank wheels to schedule timing, and don't have any prediction, so spark comes late on accel. We use every tooth and have prediction.
First good answer ! Thank you !
Peter Florance
Super MS/Extra'er
Posts: 3653
Joined: Fri Apr 02, 2004 8:40 pm
Location: Virginia Beach, VA
Contact:

Re: Acceleration Ignition correction

Post by Peter Florance »

ruzki wrote:
Posting unsubstantiated requests helps nobody.
I want to make clear that i have not requested any feature ! Please read the first post
I got the impression that you people do not read anymore and jut switch on your "self-defense mode" .. but why ?
this post assures this
Plenty of people have requested plenty of silly things over the years.
Again the question was:
So my question is why the do the developers do not want to implement this feature ?
So, you want less torque?? Well take your foot off the throttle? Acceleration is by definition more torque/power than is required to maintain the current velocity.
Right !! and now tell this a woman Image
I´m talking about highly responsive engine´s, 70mm inner Diameter Throttle Body on an 2.0 4cyl. for example, i bet non of us can push the gas pedal gentle enough to maintain a smooth acceleration from very low velocity.
I'm not even sure that is Ecumasters intended use for that feature. I'll ask someone I know who uses that product.
ask me !
I'm done here.
Peter Florance
PF Tuning
81 BMW Euro 528i ESP Car
60-2 Wheel LS2 Coils, Low Z Inj
Co-Driver 1999 BMW E46 DSP car.
jsmcortina
Site Admin
Posts: 39585
Joined: Mon May 03, 2004 1:34 am
Location: Birmingham, UK
Contact:

Re: Acceleration Ignition correction

Post by jsmcortina »

Yep, troll alert.

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
ruzki
Helpful MS/Extra'er
Posts: 63
Joined: Thu Nov 01, 2007 1:06 pm
Location: Germany
Contact:

Re: Acceleration Ignition correction

Post by ruzki »

Yep, troll alert.
I don´t think that i deserve to be called troll, just because i asked questions wich are not welcome ... but Ok ! i´m out ! ..bye
Matt Cramer
Super MS/Extra'er
Posts: 17499
Joined: Thu Apr 16, 2009 8:08 pm

Re: Acceleration Ignition correction

Post by Matt Cramer »

The only good explanation I've seen for this feature - when not being used as a correction for an ECU with a second rate wheel decoder - is to reduce driveline shock loads by making throttle response softer.

I have also seen a lot of baloney reasons people have asked for this.
Matt Cramer -1966 Dodge Dart slant six running on MS3X
DaveEFI
Super MS/Extra'er
Posts: 4175
Joined: Sun Apr 15, 2012 12:55 am
Location: SW London, UK

Re: Acceleration Ignition correction

Post by DaveEFI »

ruzki wrote:
Yep, troll alert.
I don´t think that i deserve to be called troll, just because i asked questions wich are not welcome ... but Ok ! i´m out ! ..bye
You asked a question without giving the reasons why you though such a feature was needed?

If you have a particular problem MS related, plenty of experts here will help with it. Including those who actually write the software, who I, for one, am incredibly grateful to. Not many products on the market where this is the case.

There is always more than one way to skin a cat. :D
Rover SD1 3.5 EFI
MS2 V3
EDIS
Tech Edge O2
London UK.
kjones6039
Super MS/Extra'er
Posts: 1986
Joined: Sat Jul 22, 2006 8:02 pm
Location: Eureka, NV USA
Contact:

Re: Acceleration Ignition correction

Post by kjones6039 »

Just want to reinforce what Dave has already pointed out here. Where else in the automotive industry (or elsewhere for that matter) can you get direct access to the developers??? That ain't gonna happen anywhere else except on this forum, I don't think!!!

Ken

Dave,
Are you back to skinning cats again? :lol:
1979 Corvette - 383 CID SBC w/ Holley Pro-Jection 900 CFM TBI, 4-85 lb lo-z injectors & Walbro 255 pump
MS2 v3 w/extra 3.4.2 Release
36-1, Delphi LS2/7 coils in wasted spark, driven by v2.0 logic board from JBPerformance
Spartan Lambda Sensor from 14point7
TinyIOX from JBPerformance
sd1nl
Master MS/Extra'er
Posts: 470
Joined: Wed Apr 11, 2012 3:21 am
Location: Netherlands

Re: Acceleration Ignition correction

Post by sd1nl »

It is meant to soften snatchy throttle response especially on responsive engine with manual transmissions to soften driveline shocks.

It can also prevent pinging when hitting the throttle hard after shifts, just by momentarily retarding ignition.

Most OEM systems use this also.

Probably most engines won't benefit from it, but I also have asked for this "tip in retard" function.
Rover Vitesse 3.5
MS3 full-sequential
36-1 triggerwheel
Direct coil control
Innovate LC1 wideband lambda sensor
muythaibxr
Site Admin
Posts: 8228
Joined: Thu Oct 14, 2004 12:48 pm

Re: Acceleration Ignition correction

Post by muythaibxr »

Ah, I misunderstood the request. I was thinking that people wanted more advance when RPM is increasing faster. People have asked for that, and I've always thought of it as a band-aid for poorly written wheel decoders.

TPS rate of increase-based retard of ignition timing IMHO has merit, though again it is at least partially to account for the ECU and rest of the system's inability to keep up with fast increases in load. In other words the physical system changes faster than the ECU can sense, so you add a fudge factor to retard a little faster than the MAP changing in the manifold, the sensors ability to sense the change, the lag factor's filtering of the change, and the table lookup based on all that allow you to do otherwise.

In my experience this can largely be tuned around on MAP/Alpha-N/ITB-mode cars by getting a stable MAP signal and then getting rid of lag factor. With MAF I can see it being a bigger issue, which would explain why the factories do it.

Ken
Megasquirt is not for use on pollution controlled vehicles. Any advice I give is for off road use only.
Post Reply