Pages: [1]
Author Topic: Deceleration timing, Engine Braking  (Read 2825 times)
mattytdi
Jr. Member
**

Karma: +0/-0
Offline Offline

Posts: 49


« on: June 23, 2021, 11:53:14 AM »

Good day all.
I did a few searches, but could not find any info regarding deceleration, or engine braking.
My car 2005 1.8t quattro A4, seems to go to about 3* timing when the throttle is released during deceleration.
I would prefer to see a bit more advance, to have the engine slow ( bring down the revs) faster.
I know this little motor can not contribute alot to engine braking, and it's intertial (rotating) mass isn't helping, but I would prefer it to drop revs a bit faster.
I don't know which maps to access to adjust that low (0deg) throttle range.
If anyone can point me in the correct direction, or any suggestions would be appreciated!
Thanks!
Logged

Norwegian1.8T
Full Member
***

Karma: +1/-1
Offline Offline

Posts: 72


« Reply #1 on: June 24, 2021, 04:37:40 AM »

KFZWMN, minimal ignition angle. Try raising it on the parts you want. Ignition angle will never be lower than this map
Logged
prj
Hero Member
*****

Karma: +1072/-487
Offline Offline

Posts: 6045


« Reply #2 on: June 24, 2021, 06:44:32 AM »

Seems like a troll post, but I'll bite.
Ignition timing makes zero difference because the injection is switched off during decel.

Probably you're talking about throttle angle?
There's a minimum throttle angle that can be set and 0 is not always it. Is the throttle physically capable of going that low?
Set application mode for direct throttle control and test with ignition on or maybe output test will show it.

Either way, this is a waste of time.
If you need more engine braking use a higher gear when decelerating!
If you have autobox, let IT use a higher gear when decelerating and keep the TCC shut.

This will make ten times more difference.
Logged

PM's will not be answered, so don't even try.
Log your car properly - WinOLS database - Tools/patches
Blazius
Hero Member
*****

Karma: +89/-40
Offline Offline

Posts: 1282



« Reply #3 on: June 24, 2021, 11:32:15 AM »

Yeah I was about to post before leaving for work, why do you think ignition angle matters when when on overrun? There is no actual combustion happening unless you have changed some maps, or unburnt fuel is combusting late aka pop and ban and all that

If you wanna hold RPM on decel for some reason you can change the shutoff maps to keep injecting fuel but I advise its not a good idea, but from the looks of it you want it to drop the RPM faster in gear?

As for 0 throttle angle, no you cant do that even with cwmdapp direct control im 95% sure, unless you change the need map , fpwdkapp or something I forgot, to 0 at 0 pedal position, but it wont work because there are conditions that will take over the min throttle plate angle which is like 2-3% in my experience, prolly doable with asm or some other FR condition tracking but I think this is a waste of time.
Logged
stuydub
Full Member
***

Karma: +25/-12
Offline Offline

Posts: 230


« Reply #4 on: June 25, 2021, 01:23:15 AM »



As for 0 throttle angle, no you cant do that even with cwmdapp direct control im 95% sure, unless you change the need map , fpwdkapp or something I forgot, to 0 at 0 pedal position, but it wont work because there are conditions that will take over the min throttle plate angle which is like 2-3% in my experience, prolly doable with asm or some other FR condition tracking but I think this is a waste of time.

KFWDKMSN Map for desired throttle plate angle
KFWDKPP    Throttle blade position dependent on air charge signal
Logged
Blazius
Hero Member
*****

Karma: +89/-40
Offline Offline

Posts: 1282



« Reply #5 on: June 25, 2021, 04:16:21 AM »

KFWDKMSN Map for desired throttle plate angle
KFWDKPP    Throttle blade position dependent on air charge signal


Those maps arent active if you set fuedk without momentstructure, wdksap will be the final throttle blade output which comes mainly from FPWDKAPP (+ a temp based offset) or a set value depending on how you set the appropiate bits up and ignition on (starting) throttle angle is already offset to ensure engine start, but like I said there are most likely min values that wont allow the throttle angle to below a certain number no matter what you put in fpwdkapp at 0% wped when the engine is running, never tried though in my 2 years of running with fpwdkapp.


PS. Anyway kinda derailed the topic, what you are trying to achieve OP is a waste of time with no real benefits, specially on a manual car.
« Last Edit: June 25, 2021, 09:11:38 AM by Blazius » Logged
Pages: [1]
  Print  
 
Jump to:  

Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Page created in 0.022 seconds with 17 queries. (Pretty URLs adds 0s, 0q)