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 Post subject: Re: Deceleration
PostPosted: Thu Mar 16, 2017 12:53 am 
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Joined: Sun Sep 06, 2015 2:16 pm
Posts: 144
eotuzalti wrote:
What do I have to do if I want to achieve such a result ??


https://youtu.be/6TRWuhU-FHo


Hey it's my video ;) Is it you who has sent me an email about this ?


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 Post subject: Re: Deceleration
PostPosted: Thu Mar 16, 2017 4:38 pm 
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Joined: Wed Mar 15, 2017 1:34 am
Posts: 18
M52Drifter wrote:
eotuzalti wrote:
What do I have to do if I want to achieve such a result ??


https://youtu.be/6TRWuhU-FHo


Hey it's my video ;) Is it you who has sent me an email about this ?



Yes it is me, thank you very much dude ! I even programmed an harder limiter today, i only want that exhaust crackle thing but that aggressive crackle.


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 Post subject: Re: Deceleration
PostPosted: Tue Apr 18, 2017 9:01 am 
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Senior Member

Joined: Mon May 18, 2015 8:14 am
Posts: 1042
Location: Oulu, Finland (English/Finnish)
There has been lot of discussion about how to get rid of the rev hang which is present at least in ms41.0. I tried lot of things like using the ms41.2 deceleration maps but I wasn't happy with the result. It was better but still the revs didn't drop as fast I would want. I also played with the Fast decreasing TPS -detection maps, but with those I couldn't get the result I wanted, and in most cases it just made the car undriveable. Like there would have been kangaroo gas in tank :D

But eventually I found easy way to get totally rid of the rev hang without negative effects:
- First raise the ignition Retard - Decreasing TPS - step size so that the minimum values are 10.
- Lower the Ignition retard decreasing TPS (closed) maps by 10.
- Lower the Ignition retard decreasing TPS maps by 15.

Then flash the new SW and go for test drive. There shouldn't be any rev hang at all. Here is ms41 file you could use to copy the maps: https://drive.google.com/open?id=0B2EFG ... 1JrTjFhQUk

Then in addition to that if you want lot of exhaust popping when deceleration:
- Put the Fuel restore - RPM maps above your RPM limiter. So that it wont cut fuel when you are decelerating. (you need fuel for those pops).
- Lower the Ignition retard decreasing TPS -maps by another 10 degrees compared to the previous setup.

This will get your deceleration sound like this (I have almost stock exhaust so it's not very loud):
https://pazi88.kuvat.fi/kuvat/random+pa ... I_9618.MOV

(I will add file later)

Then if you want it more aggressive you could increase the step size and lower the Ignition retard decreasing TPS -maps even more. While decelerating you would want about negative 20 degrees of advance for loud pops so use logging to found how much you will need to lower the Ignition retard decreasing TPS -maps. but 20 to 25 lower than stock will give the same effect as in that video. I didn't want to test more because THIS WILL DESTROY YOUR CAT. And if you don't have CAT and want flames you could add some unnecessary fuel to base fuel map to the lowest load column above 1600 RPM.

Personally I would want few seconds of popping when lifting the throttle and with those mods you will get constant popping. So I will later test this:
mrf582 wrote:
Enabled wrote:
Any way to make the exhaust burble for just a couple of seconds, instead of constant?

Leave the "Fuel Restore - RPM" tables stock (around the 1100 RPM range) and increase the "RPM Hystersis (Maximum)" to a value that is sufficiently high. For example, if "Fuel Restore - RPM" is at 1100 RPM and 'Fuel Cut - Hystersis (Max)' is set to 6900, then the effective Fuel Restore RPM is 8000 immediately after the throttle is closed. After a programmable delay, the ECU will switch to the 'Hystersis - (Min)' value (160 stock) so the effective Fuel Restore RPM will be 1100 plus 160 = 1260 after a short time.

Then adjust the "Fuel Cut - Hystersis Delay Counter" to your preference. Increase value (240 injection cycles is stock) to have the exhaust burble for longer. This value is set to 240 when throttle is closed and is slowly decremented while the throttle is closed but engine speed is below the 'effective Fuel Restore RPM'. Once this delay runs out, the engine speed will be above the effective FR RPM and the injectors will shut off.


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 Post subject: Re: Deceleration
PostPosted: Tue Apr 18, 2017 1:21 pm 
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Experienced

Joined: Thu Sep 25, 2014 12:53 pm
Posts: 627
Location: Houston, TX
I am running mrf582's recommendation for just a brief short exhaust crackle, it works well, but I haven't fine tuned it enough. It's a little inconsistent on my car, does it more often on low loads. But it's nice enough.

Constant crackles gets annoying quickly.


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 Post subject: Re: Deceleration
PostPosted: Tue Apr 18, 2017 1:30 pm 
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Senior Member

Joined: Mon May 18, 2015 8:14 am
Posts: 1042
Location: Oulu, Finland (English/Finnish)
Enabled wrote:

Constant crackles gets annoying quickly.


Yeah I noticed :D It was funny about 10 minutes and then it got annoying.


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 Post subject: Re: Deceleration
PostPosted: Tue Apr 18, 2017 7:17 pm 
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Newbie

Joined: Sun Jul 27, 2014 4:42 pm
Posts: 84
I think "ideal" program will be something like this https://youtu.be/6RgZLp2CxOQ?t=1m42s

i know that is racecar on standalone but this i how I imagine what happen:

He brakes - foot of throttle quickly, so ecu send in few cycles of fuel quite lot of fuel with ingnition retarded - that cause no rev hang and backfire, and after this point engine do not open injector anymore

Friend of mine have fully stock ecu setting and bigger injectors, turbo and his car is backfiring on stock settings ECU setting after letting of gas pedal:

https://youtu.be/PeKvzk0OWeA?t=2m6s



In pazzi88 "manual" when tweaking fuel restore point about limiter this cant be achieved i think

Maybe key is in fuel enleanment decreasing TPS table - leave fuel restore stock but add some fuel in this table to have "backfire"


Last edited by gasp0 on Wed Apr 19, 2017 5:01 am, edited 1 time in total.

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 Post subject: Re: Deceleration
PostPosted: Tue Apr 18, 2017 9:54 pm 
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Experienced

Joined: Thu Sep 25, 2014 12:53 pm
Posts: 627
Location: Houston, TX
The key is in the Hysteresis Delay Counter, and it does work for the most part.


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 Post subject: Re: Deceleration
PostPosted: Wed Apr 19, 2017 5:01 am 
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Newbie

Joined: Sun Jul 27, 2014 4:42 pm
Posts: 84
my car is not driveable right now, but has anybody chceck what fuel map fields is car using during deceleration when throttle is liffted ?


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 Post subject: Re: Deceleration
PostPosted: Wed Apr 19, 2017 5:17 am 
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Experienced

Joined: Tue Jan 24, 2017 7:58 am
Posts: 478
so providing the delay hysteresis is set correctly, by then adding more fuel you should see a flame or two ?


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 Post subject: Re: Deceleration
PostPosted: Wed Apr 19, 2017 5:23 am 
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Senior Member

Joined: Mon May 18, 2015 8:14 am
Posts: 1042
Location: Oulu, Finland (English/Finnish)
328i-sport-rossi wrote:
so providing the delay hysteresis is set correctly, by then adding more fuel you should see a flame or two ?


And then all the ignition retard added that I mentioned. Of course you need basically straight pipe or at least straight through mufflers without cat to be able to see any flames.


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 Post subject: Re: Deceleration
PostPosted: Wed Apr 19, 2017 8:49 am 
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Experienced

Joined: Tue Jan 24, 2017 7:58 am
Posts: 478
I have full decat center section, I already get a blue flame at WOT on gear change at high rpm, im now hoping for more :)


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 Post subject: Re: Deceleration
PostPosted: Wed Apr 19, 2017 9:05 am 
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Experienced

Joined: Tue Jan 24, 2017 7:58 am
Posts: 478
gasp0 wrote:
my car is not driveable right now, but has anybody chceck what fuel map fields is car using during deceleration when throttle is liffted ?


I would also like to know this so i know where to add the fuel for the bigger bang


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 Post subject: Re: Deceleration
PostPosted: Wed Apr 19, 2017 9:09 am 
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Experienced

Joined: Tue Jan 24, 2017 7:58 am
Posts: 478
pazi88 wrote:
There has been lot of discussion about how to get rid of the rev hang which is present at least in ms41.0. I tried lot of things like using the ms41.2 deceleration maps but I wasn't happy with the result. It was better but still the revs didn't drop as fast I would want. I also played with the Fast decreasing TPS -detection maps, but with those I couldn't get the result I wanted, and in most cases it just made the car undriveable. Like there would have been kangaroo gas in tank :D

But eventually I found easy way to get totally rid of the rev hang without negative effects:
- First raise the ignition Retard - Decreasing TPS - step size so that the minimum values are 10.
- Lower the Ignition retard decreasing TPS (closed) maps by 10.
- Lower the Ignition retard decreasing TPS maps by 15.

Then flash the new SW and go for test drive. There shouldn't be any rev hang at all. Here is ms41 file you could use to copy the maps: https://drive.google.com/open?id=0B2EFG ... 1JrTjFhQUk

Then in addition to that if you want lot of exhaust popping when deceleration:
- Put the Fuel restore - RPM maps above your RPM limiter. So that it wont cut fuel when you are decelerating. (you need fuel for those pops).
- Lower the Ignition retard decreasing TPS -maps by another 10 degrees compared to the previous setup.

This will get your deceleration sound like this (I have almost stock exhaust so it's not very loud):
https://pazi88.kuvat.fi/kuvat/random+pa ... I_9618.MOV

(I will add file later)

Then if you want it more aggressive you could increase the step size and lower the Ignition retard decreasing TPS -maps even more. While decelerating you would want about negative 20 degrees of advance for loud pops so use logging to found how much you will need to lower the Ignition retard decreasing TPS -maps. but 20 to 25 lower than stock will give the same effect as in that video. I didn't want to test more because THIS WILL DESTROY YOUR CAT. And if you don't have CAT and want flames you could add some unnecessary fuel to base fuel map to the lowest load column above 1600 RPM.

Personally I would want few seconds of popping when lifting the throttle and with those mods you will get constant popping. So I will later test this:
mrf582 wrote:
Enabled wrote:
Any way to make the exhaust burble for just a couple of seconds, instead of constant?

Leave the "Fuel Restore - RPM" tables stock (around the 1100 RPM range) and increase the "RPM Hystersis (Maximum)" to a value that is sufficiently high. For example, if "Fuel Restore - RPM" is at 1100 RPM and 'Fuel Cut - Hystersis (Max)' is set to 6900, then the effective Fuel Restore RPM is 8000 immediately after the throttle is closed. After a programmable delay, the ECU will switch to the 'Hystersis - (Min)' value (160 stock) so the effective Fuel Restore RPM will be 1100 plus 160 = 1260 after a short time.

Then adjust the "Fuel Cut - Hystersis Delay Counter" to your preference. Increase value (240 injection cycles is stock) to have the exhaust burble for longer. This value is set to 240 when throttle is closed and is slowly decremented while the throttle is closed but engine speed is below the 'effective Fuel Restore RPM'. Once this delay runs out, the engine speed will be above the effective FR RPM and the injectors will shut off.



My "Fuel Cut - Hystersis Delay Counter" stock is 56 and my "Fuel Cut - RPM Hystersis Delay (Min)" is 224

This differs massivly from what is written above, why is this.


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 Post subject: Re: Deceleration
PostPosted: Wed Apr 19, 2017 9:20 am 
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Senior Member

Joined: Wed Jan 22, 2014 6:54 pm
Posts: 1773
Are you running 412 id:12?


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 Post subject: Re: Deceleration
PostPosted: Wed Apr 19, 2017 3:46 pm 
Offline
Newbie

Joined: Sun Jul 27, 2014 4:42 pm
Posts: 84
Hi guys, today ive tryed settings like this:

Resuults are no rev hang which make me quite happy: https://www.youtube.com/watch?v=YcZAZKRalcA

Exhaust poping is occuring very verry randomly only on when slowly letting of gas usually on lower rpm but its still quite random :(

tomorow i wanna try to chech infuence of IR - fast decreasing TPS ...

i do not check for glames :lol:


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