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 Post subject: Re: Deceleration
PostPosted: Thu Apr 20, 2017 1:02 am 
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Joined: Mon May 18, 2015 8:14 am
Posts: 1042
Location: Oulu, Finland (English/Finnish)
I also did some fine tuning.

I noticed that editing only the "ignition retard - decreasing TPS -step size" -table makes the engine very twitchy when engine is cold (close to 0 degrees Celsius). So I left that stock and edited the "ignition retard - decreasing TPS -step size (ECT compensation) -table so that at -10 and 30 degrees Celsius it's stock. But then ECT at 60 the step size is 5 degrees and then ECT at 82 the step size is at 10 degrees. Now the engine is calm as stock when it's cold but then when it's warmed up, all the rev hang is gone. Just like before.

I also tested the mrf582 suggestion and it works quite well. If I lift of the thortle little bit, the engine pops for some time while decelerating. But if I fully lift off the throttle, it immediately cuts of fuel. It's quite good but maybe little bit fine tuning is still needed.


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 Post subject: Re: Deceleration
PostPosted: Thu Apr 20, 2017 4:59 am 
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Joined: Sun Jul 27, 2014 4:42 pm
Posts: 84
My brother drives citroen saxo with some engine mods but stock ecu, and when exhaust fall off (lol) you hear that when you lift off slowly it poops to exhaust and no rev hang - for about second after lifting off throttle depending on rpm...
But my BMW when i go WOT and lift offf to TPS 0 (lets say durring loonger braking) it looks like fuel is cutted right away - saxo is popping also when you lift of after wot like this https://youtu.be/ei2XNf23ijM?t=1m29s

I will try today finally take some logs ..., my goal is to get rid of rev hang and have pop from exhaust when lift off after WOT


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 Post subject: Re: Deceleration
PostPosted: Thu Apr 20, 2017 4:33 pm 
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Joined: Sun Jul 27, 2014 4:42 pm
Posts: 84
Hello today ive tried following settings:

Results - wot throttle then lift off - no poping in exhaust :(
REV hang - none
Lifting of veeery gently low rpm - poping like crazy
funny thing is when you are going lets say 5000rpm 3rd gear, hit the clutch and than release, its starts poping till car reach like 1500rpm ... so quite long time :D

ou and with these setting you get this also :

https://youtu.be/F4fvMsWgbfY

tomorow i will try to make some logs :)


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 Post subject: Re: Deceleration
PostPosted: Fri Apr 28, 2017 6:04 am 
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Joined: Tue Jan 24, 2017 7:58 am
Posts: 478
I ran the above setting, pulls timing on deceleration and get pops and also flames but it takes around 4 seconds for engine braking to take effect and you can really feel it happening.

Any ideas how i can eliminate the 4 second delay ?


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 Post subject: Re: Deceleration
PostPosted: Sat Apr 29, 2017 4:20 am 
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Joined: Sat Jan 14, 2017 5:46 pm
Posts: 534
Have a look at "fuel restore rpm" table (at the end of the table) ;).
Everything you need is in deceleration tables, for nice deceleration with no rev hangs you also have to modify some fast degreasing TPS tables.
Some had good values for M52B25 tested?


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 Post subject: Re: Deceleration
PostPosted: Tue May 23, 2017 1:31 am 
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Joined: Wed Apr 12, 2017 6:01 am
Posts: 1
After testing some of these settings in comparison to the M3 and my original 323i tables, I want to understand some of the settings that you have all used. It seems that pazi88's decel maps are tuned using different ideology to the m3 maps.

M3 tables produce reduced jerk in engine deceleration (over original 323i tables), especially in stop/start traffic but its also noticeable at high rpm. After implementing pazi88's ignition retard maps, the jerk on fast and slow closed throttle is much greater.

Basically I want to figure out if it's possible to remove high rpm rev hang (above 2k rpm) while maintaining low rpm driveability. At very load engine speed and engine load, we'd want low initial timing retard with a small stepsize so that engine braking occurs gradually. Then at high engine speed and engine load we'd want the opposite? I guess I need to log the change in load vs rpm from 4k rpm to idle to accurately find at what loads occur during deceleration.

Do people agree with this train of thought?


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 Post subject: Re: Deceleration
PostPosted: Tue May 23, 2017 3:40 pm 
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Senior Member

Joined: Mon May 18, 2015 8:14 am
Posts: 1042
Location: Oulu, Finland (English/Finnish)
I have made some progress. Easiest way of getting rid of the rev-hang in ms41.0 without negative effects just edit the "Ignition retard - Decreasing TPS - Step Size (ECT compensation) to look like this:
Attachment:
decel.png


No other modifications needed. If it's too aggressive raise the 60 an 82 degree values little bit.

If you want exhaust pops in addition to that lower the three "Ignition retard - Decreasing TPS" by 10 to 20 degrees, depending how aggressive you want it to be. And raise the "Fuel restore RPM" values above the rev limiter.

The short burst of exhaust popping is still under study but rising the "Fuel cut - RPM Hysteresis (Maximum)" to 6900 instead of "Fuel restore RPM" makes it happen. But the effect is bit random, so it still needs some work.


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 Post subject: Re: Deceleration
PostPosted: Wed May 24, 2017 3:48 am 
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Joined: Tue Jan 24, 2017 7:58 am
Posts: 478
I Have been using these modifications already but as you say they are a little random, I have found playing about with "Detection-Fast decreasing TPS " has an effect when coming off throttle at WOT, on closing of the throttle at this point and i managed pops when changing gear.


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 Post subject: Re: Deceleration
PostPosted: Fri May 26, 2017 9:18 am 
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Joined: Tue Jan 24, 2017 7:58 am
Posts: 478
cmor7965 wrote:
After testing some of these settings in comparison to the M3 and my original 323i tables, I want to understand some of the settings that you have all used. It seems that pazi88's decel maps are tuned using different ideology to the m3 maps.

M3 tables produce reduced jerk in engine deceleration (over original 323i tables), especially in stop/start traffic but its also noticeable at high rpm. After implementing pazi88's ignition retard maps, the jerk on fast and slow closed throttle is much greater.

Basically I want to figure out if it's possible to remove high rpm rev hang (above 2k rpm) while maintaining low rpm driveability. At very load engine speed and engine load, we'd want low initial timing retard with a small stepsize so that engine braking occurs gradually. Then at high engine speed and engine load we'd want the opposite? I guess I need to log the change in load vs rpm from 4k rpm to idle to accurately find at what loads occur during deceleration.

Do people agree with this train of thought?


Just an update on my workings....... So i found the setting above to aggressive, Throttle was basically on or off and made it uncomfortable.
So what i done.......
I just retarded "Decreasing TPS" by around -5 throughout.
I retarded "Decreasing TPS (Closed) by -5 throughout.
I the adjusted Fuel Cut "Delay Counter"to 86 , just a minor adjustment.

Then to try and create Flames i added fuel in the first two columns of the base fuel map from 5000rpm to 6500rpm so that hopefully it hits these cells in deceleration.

Outcome......... It works a treat and im having some lovely flames. :)


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 Post subject: Re: Deceleration
PostPosted: Mon May 29, 2017 9:37 am 
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Joined: Sun Jul 27, 2014 4:42 pm
Posts: 84
328i-sport-rossi wrote:
cmor7965 wrote:
After testing some of these settings in comparison to the M3 and my original 323i tables, I want to understand some of the settings that you have all used. It seems that pazi88's decel maps are tuned using different ideology to the m3 maps.

M3 tables produce reduced jerk in engine deceleration (over original 323i tables), especially in stop/start traffic but its also noticeable at high rpm. After implementing pazi88's ignition retard maps, the jerk on fast and slow closed throttle is much greater.

Basically I want to figure out if it's possible to remove high rpm rev hang (above 2k rpm) while maintaining low rpm driveability. At very load engine speed and engine load, we'd want low initial timing retard with a small stepsize so that engine braking occurs gradually. Then at high engine speed and engine load we'd want the opposite? I guess I need to log the change in load vs rpm from 4k rpm to idle to accurately find at what loads occur during deceleration.

Do people agree with this train of thought?


Just an update on my workings....... So i found the setting above to aggressive, Throttle was basically on or off and made it uncomfortable.
So what i done.......
I just retarded "Decreasing TPS" by around -5 throughout.
I retarded "Decreasing TPS (Closed) by -5 throughout.
I the adjusted Fuel Cut "Delay Counter"to 86 , just a minor adjustment.

Then to try and create Flames i added fuel in the first two columns of the base fuel map from 5000rpm to 6500rpm so that hopefully it hits these cells in deceleration.

Outcome......... It works a treat and im having some lovely flames. :)



how are you rpm hysteresis settings? any video ? :)


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 Post subject: Re: Deceleration
PostPosted: Tue May 30, 2017 12:55 pm 
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Senior Member

Joined: Wed Jan 22, 2014 6:54 pm
Posts: 1773
328i-sport-rossi wrote:

Just an update on my workings....... So i found the setting above to aggressive, Throttle was basically on or off and made it uncomfortable.
So what i done.......
I just retarded "Decreasing TPS" by around -5 throughout.
I retarded "Decreasing TPS (Closed) by -5 throughout.
I the adjusted Fuel Cut "Delay Counter"to 86 , just a minor adjustment.

Then to try and create Flames i added fuel in the first two columns of the base fuel map from 5000rpm to 6500rpm so that hopefully it hits these cells in deceleration.

Outcome......... It works a treat and im having some lovely flames. :)

Do you have screen shots?
I'm guessing you mean:
Ignition Retard - Decreasing TPS
Ignition Retard- Decreasing TPS (Closed)
Fuel Cut - Hysteresis Delay Counter
?


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 Post subject: Re: Deceleration
PostPosted: Tue May 30, 2017 4:10 pm 
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Experienced

Joined: Tue Jan 24, 2017 7:58 am
Posts: 478
busterhax wrote:
328i-sport-rossi wrote:

Just an update on my workings....... So i found the setting above to aggressive, Throttle was basically on or off and made it uncomfortable.
So what i done.......
I just retarded "Decreasing TPS" by around -5 throughout.
I retarded "Decreasing TPS (Closed) by -5 throughout.
I the adjusted Fuel Cut "Delay Counter"to 86 , just a minor adjustment.

Then to try and create Flames i added fuel in the first two columns of the base fuel map from 5000rpm to 6500rpm so that hopefully it hits these cells in deceleration.

Outcome......... It works a treat and im having some lovely flames. :)

Do you have screen shots?
I'm guessing you mean:
Ignition Retard - Decreasing TPS
Ignition Retard- Decreasing TPS (Closed)
Fuel Cut - Hysteresis Delay Counter
?


correct, currently trying to get the logger to work again due to a java error i cannot fix, if i dont smash this laptop into a millions pieces i will get a screen shot.


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 Post subject: Re: Deceleration
PostPosted: Thu Jun 01, 2017 7:17 am 
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Newbie

Joined: Sun Jul 27, 2014 4:42 pm
Posts: 84
Hi guys

yesterday i have some time so ive done few tests ...

setup 1:

very little pops when driving, but here is something, when reving looks like this, very nice reaction to throttle:

https://www.youtube.com/watch?v=P1tjrUQ-9x4

SETUP: test1

setup2:
pops from exhaust when driving, mainly in lower rpm, not bad, but still little bit random
https://www.youtube.com/watch?v=_XykQl9B7wg

SETUP: test2

setup3:
long pops when driving, but still little bit random, no pops when going off throttle on high load,
https://www.youtube.com/watch?v=pXSUJEcle9A

SETUP: test3


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 Post subject: Re: Deceleration
PostPosted: Fri Jun 02, 2017 5:09 am 
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Experienced

Joined: Tue Jan 24, 2017 7:58 am
Posts: 478
All of the above looks great but im still not able to determine when the deceleration tables are active or when it just uses the base timing map for deceleration.
Its still very much a grey area for me as to knowing what Table the ECU is using at what time.


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 Post subject: Re: Deceleration
PostPosted: Fri Jun 02, 2017 9:04 am 
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Senior Member

Joined: Wed Jan 22, 2014 6:54 pm
Posts: 1773
328i-sport-rossi wrote:
All of the above looks great but im still not able to determine when the deceleration tables are active or when it just uses the base timing map for deceleration.
Its still very much a grey area for me as to knowing what Table the ECU is using at what time.

I've told you several times. If you enable the fuel injectors during deceleration mode, it will use the base map + modifiers. If you leave the fuel restore table original, injectors are turned off during deceleration.


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