DIY Finetuning throttle closure on overboost (S55)

[Skevo8]

Been adjusting my map a bit here and there (S55 - 1A841D2801 sw version), but one thing I would like to smoothen is the throttle position adjustment than happens on the slight overboost at around 3100rpm - see logged 4th gear and 3rd gear pull.
Any quick hint where to adjust without tampering with the map too much? If it is too coumbersome to adjust then I will leave it - the map is very smooth and nice to drive - do not want to destroy it

Not sure if this is to be handled by Boost or Throttle tables - do not see some obvious choice there.

thanks

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other logs here:

26.3.2021 GTSedit13 3rd a 4th

www.spoolstreet.com

 

[GreyNBlueE92]

If I remember right you reduce throttle closure table above. I forget exactly what mine is, I think around 0.875ish it's on v8baits guide I'm pretty sure. I'm also N54 but might be the same

 

[Skevo8]

Thanks for the point.
Just was a bit confused as cobb tuning guide says:
Threshold (Major Throttle Closures) – Tuning Tips – Raising these values closer to 1.0 will dampen the DME’s throttle plate adjustments during throttle closures and overshoots.
- will try.

v8bait guide referes to : Threshold (Major Throttle Closure) change to: 0.960 (makes DTC and traction control a little less invasive)

And my values are already pretty close to 1

 

[GreyNBlueE92]

Those are the guides I used. They should be right. I haven't looked at my XDF in months... Small changes can change a lot. Just gotta play with it. Good luck!

 

[Skevo8]

Ideally I would like to have the throttle to be at 73-75 at this point (see pic) - will have slightly slower boost build up - but at least no correction would be needed. WGDC seems to be pretty spot on without any unecessary correction. But can't seem to understand where to map the throttle opening table.

wouldn't that table below do the necessary adjustment?

 

[BloodyZ4]

Don't mess with the throttle maps, you need to taper boost in those areas, remove some wgdc or adjust your p-factor to catch the overboost faster, or you could adjust your load target so you don't overshoot. If your are below your boost target the DME won't close the throttle if the traction control doesn't intervene.

 

[Skevo8]

Thanks, but if you take a look on the log in the first post, you see that during the spool (2300rpm and above), the accel pedal is 100% but the throttle position is starting at cca 55% at starts goes up to cca 82% when the load is over Load req, the throttle position corrects from 84% to 33% and the recovers slowly as the RPM goes. WGDC doesnot show any abrupt corrections - that is why I am somehow resisting to touch it and looking for some advise how to make the thorttle curve slightly flatter on spool - ie 76 at 3000rpm.

 

[BloodyZ4]

You could try lowering the max throttle at those rpms, but that would be a bandaid, not a real solution. Your DME is closing the throttle because your are overboosting and it takes some time to recover.

 

[Skevo8]

I understand the theory, it is just the logs that are telling me otherwise. Even on stock map, the spool is beeing done using 100% WGDC and the Throttle position being adjusted from low 40% (and becasue the target Load/Boost on stock map is low - it stays at around that 40ish %) - slightly overshoots - but is OK from that point. See stock log below
That is why I am trying to understand the map/process which is commanding the throttle position % though the boost build up sequence - and it is not WGDC based on what is see in the logs. Even MHD OTS GTS map has the tendency overshhot from time to time - it is just their Throttle opening goes cca 10% lower than mine - which is what I want to achieve in my map - but I do not know how mustbe some table that i am missing/overlooking.

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[GreyNBlueE92]

Stock maps have throttle closures, a good map doesn't. It's from overboost. If you want less boost lower load target, if it overboosts lower that area in the wgdc map. No reason to have boost before it gets to your engine. It just strains the turbos imo.

 

[Skevo8]

thanks for the ideas, anyone have a second to have a look at my map (with the xdf inluded in the zip)?

This log shows what I would like to achieve in terms of throttle position opening to build the boost a bit slower (ie WGDC at cca 91%, Throttle 71% at 3050Rpm). it is by using MHD OTS GTS1 map.

8.4.2021 9:24 MHD GTS1 normal drive

Uploaded by API.

www.spoolstreet.com

and this is my log (WGDC 91|%, Throttle 88% (!!!) at 3050rpm):

8.4.2021 18:31 GTSedit-1.01 4g 5g 3g

Uploaded by API.

www.spoolstreet.com

So where am I supposed to touch the limits/tables (boost, load, wgdc)? Since it is very close - it is just the 2500-3000Rpm throtle ramp up which I am not able to set.

 

[P33P33]

This is how it works in n54 and I'm 99% sure it's the same logic in n55, s55.

 

[Skevo8]

Thank you. Now it makes more sense to me Do you possibly have other diagrams as well? Can you PM me links if these are not public? thanks again