NefMoto

So, I read lots of stuff (S4wiki, a really great doc for tuning the 1.8TT, a ton of threads on here), I then examined my ori and tune from another tuner to see what changes had been made to the file.

I attempted to make my first tune, however it's doing some really really weird things - the big one is that I see maximum load nearly all the time, but yet don't hit my target boost pressure?

On the other tune the car can make 2300MBAR boost so it's not a hardware fault - definitely something I did.

I changed a few limiters as I wondered if it was something I'd missed that was holding the boost back. Lambda does what it's told, timing does what its told, pops work...just I've made a big mistake somewhere in the load maps. The version 2 tune requested the target boost immediately, then cut the boost back by the time I hit second gear without ever making it. Then the request drops.

I have attached all the files in the hope that someone might be able to offer advice;

Tune version 1, and a road log.
Tune version 2, a road log, a stationary revving the car log (you can see here it makes the boost request, and the weird issue with engine load)
Ori file
My map pack - slightly modified variant of one I found on here to add in the pops & bangs fuel cut stuff.

Can anyone give me any tips as to where I went wrong?  ???

Stationary revving will do nothing, and learn to tune before adding pops etc.

Is this MED9?

Agreed. Throw away everything, start from scratch. Only try to change one thing at a time.

Yes, 2.0tfsi MED9.1 - 200bhp, BWA engine.

Will start again and report findings.

Tried a few things after work - I have absolutely no idea what I was thinking when I did the KFMIOP map on the original tune. I think for whatever reason I must have tried to smooth it, and screwed up the entire table in the process.

Totally re- did KFMIRL, KFMIOP, KFLDHBN, LDRXN & LDRXNZK as per S4 tuning wiki Removed all other changes. Back to bare minimum and test.

This worked, but boost request was low. It capped at 2000-2100MBAR. Load request performed properly though, so pleased with this.

I found a few more load limiters around LDRXN (1CED46) so changed these to the same values as LDRXN, as well as a boost limiter that was set to 2250mbar.

I now have a very much drive-able tune that's quicker than stock - however load caps at 160%ish, and boost caps at about 2000-2100mbar. The request at these points is for 2340mbar (i was aiming for 2400mbar so i think request is about okay, perhaps final tweaks later), and 190% load, but I request 211% load at some points.

I haven't adjusted the axis for KFZWOP/2/KFZWOPL/2 as unsure how to calculate what values I need, nor do I completely understand it. Do i just go on linear interpolation to guess what the number ought to be?

Attached ori/tune/log, can anyone hint at whats preventing me from hitting target load/boost?

Your specified and actual load won't show over 191% on VCDS (even if it is actually). You've found the boost limiters and pressure ratio limiter, those will also cap load/boost even if you request higher load in KFMIRL and LDRXN.

So you can see you've got your request up, but the actual doesn't meet it in the mid range. What controls boost? I mean you've logged the parameter in your last log. So what maps control that output and how can you calibrate them to get the actual boost up? You must have skipped past it during your reading

Suddenly it all makes sense!

You can request all the boost in the world, but you'll never make it if the wastegate goes to 65% just as it's coming on boost!

So, by altering KFLFDIMX I've got control over what the N75 is doing? It seems to work by % in the cell is what the ECU sets the wastegate to untill another parameter or limiter in the ECU takes over....boost limiter, temperature limiter, whatever it hits first.

I need to log and play, but a basic adjustment made a massive difference to the performance of the car! Thankyou!

I assume the map is set the way it is to prevent overboost on a stock file when the K03 spools up quickly - whereas now going for 2400mbar that little turbo is absolutely flat out? Will flash it again tomorrow and see if we can get it holding where it ought to be.

I think maybe read through the PID section of the wiki properly while looking at the maps. KFLDIMX isn't percentage, but if you look at the actual pre control thread that's a sticky in the tuning section you will see how you can make it a sort of feedforward map. But yes in stock form, the I value limitation is low because the axis is target boost, so it doesn't need to go that high for the max target boost in the axis.