Hi All,

I'm trying to finetune the file in my Abarth 595 with a td04 turbo. What I've done is try to taper the boost so it targets 1.1bar between 3k-4k rpm and then request 1.45bar up to the redline, with the idea that is puts minimal stress on the drive train and gives incredible grip in lower gears - and well it just feels awesome . I am tuning MDMAXMNOTS (LDRXN on the s4wiki) to achieve the target boost.

It is working great however when going WOT between 3k-4k in 5th gear the boost overshoots the target and the car kangaroos as I think the actuator bounces around to keep it under target (see attached images), I note the throttle plate is not closing. Once you get passed 4k RPM and it requests the full boost then there is no issues and it pulls like a bat out of hell.

I read the threads on here about tuning the throttle plate but I can't find the relevant maps in my DAMOS so feel that is a deadend. There is not much info on this ECU out there, only its brother and sisters so learning from the s4wiki has been quite a challenge but I am hopefully getting there!

Does anyone have any pointers on where I should look to correct this problem? I have attached my tuned file & ori so you can rip into it/me.

Thanks in advance.

Thank you for the steps I really appreciate it. I have a J2534 interface on the way for use with your logger.

For step 2 will I need to patch the ECU? Any tips on where to start with that?

Is it affordable way for med17 to made a precontrol instead of wg flow based?

English fail, I am not sure what you mean.

But the only way to do proper precontrol calibration if you don't have an engine dyno and all the OEM data for a turbo is to get rid of the flow based crap and replace it with the good old ME7/MED9 style.
Then it works like a charm.

The boost control on these ECU's is complicated for no reason. The end resulting lde is much worse than using a standard simple pre-control map + actuator linearization.
They just model everything because there's excess computing power and they don't know what to do with it.

Today I had a look at how MoTeC do the pre-control mapping and their example had the axes as RPM & Pedal Position.

I've seen that you have the MED17 Boost Patch tool with your logger which interests me but I just want to make sure I understand it fully first.

With what you mentioned I would be mapping WGDC to RPM & Requested boost pressure. So lets say with my setup 40% wgdc gives me 1.2bar boost midrange and 55% gives me 1.45bar I would map it something like the attached, where WGDC increases up the range to taper the boost UP. Also since my map never requests more than 1.2bar until I get to 4000rpm the pink area of the map is redundant.

Sorry if that's not clear!

How to linearize boost control is here in stickies, and everything you said is pretty much wrong, there's a scientific approach to filling the map, detailed on this forum...

And yeah, I'll see if I get around to doing the patch. But calibration is still up to the end user. If you don't know what you're doing then the patch will not be useful.