Hi.

I guess this is a pretty broad question with a hell of a lot of variables.   

Let me run you down on my spec first

1.8T k03s running Audi TT BAM management
82mm 9.25:1 JE forged pistons with IE rods
AGU head with large port inlet
k03s turbo with ported manifold - stock actuator
Forge supersize dump valve - recirc
Custom free flow 2.5" pipework into a large core intercooler
AGU coilpacks
All the N valves removed for dump valve, evap, sai ETC.
3" TIP with large foam filter

At the minute, im requesting fuel as below through lamda, and using BTS as my EGT enrichement protection map.


At the moment, it seems alright on a k04 standard map,  10psi was pulling 160g/s with stock fuel and timing, but some CF's

Now ive tried to raise the load through LDRXN to mid 160s and that gives me about 15psi according to my boost gauge which appears bang on.
Only issue Im having is when in high gears, low RPM, high load situations where the ECU drops into 'soft limp' mode and limits me to 5psi until I release throttle and press it again.

Ive tried copying the KFMLDMN maf lower diagnosis table over from a 032 HN tune and that sorted all gear up until 6th where it would occasionally drop into limp.

Has anyone got any ideas what else could be causing it to drop into soft limp?

Attached is my 'latest' file which im using today.  No CF's it appears, just the occasional soft limp I describe above.   Holding 15psi pretty much throughout the revs.

Any advice would be appreciated.

Why are you upgrading your MAF on a K03?
Why do you have a K03 on a built engine?
Why have you not rescaled your LAMFA axis? The last column should be sub 100 (I'd say 95) so you're actually using it......

MAF diameter is suitable for the ecu.  im running a S3 housing on a TT map....like standard.
K03s is because the engine required running in, so opted for a standard turbo to run it in, make sure everything was OK, before I went bigger (TSFI)
LAMFA axis is standard except the 89.9974 row.  I used the k03s RPM values to give me a better fuel control on spool (like an original k03 framed turbo map would)

Yeah, but it'll interpolate between 89.99 and 100 to get a mean.  Set it to 99.99999999 and it should be reeeet. 

Still shit.

Set it to 95 or even 97.5.

Here's the thing. Running a K03 on K04 software or vice versa is a bad idea. There are maps that translate requested load into requested boost. (KFPRG, KFURL). You'll need to spend some time getting these right so you are getting the correct boost to hit requested load.

I'm a firm believer (now anyways) of using the software that was designed for the configuration. I think too many people are crossflashing these days.

Are you logging AFR? If not, that's another can of worms entirely. Running software not designed for your engine, along with a different MAF housing, there's no telling how close actual AFR is to requested. The entire calibration will be wrong. What you need to do is put the stock MAF back in, and dial in your fueling that way. Log wideband, and adjust the correction maps so that actual lambda follows requested. Then go about swapping the MAF.

I don't like your LAMFA at all though.

Cross flash meaning running a k04 file on a k03.

You change back to the stock MLHFM when you put the stock MAF back in

Airflow is measured in g/sec.

I think what ddillinger meant is put the intake back to stock while you get fueling in line and get AFR actual to meet requested.

I think dd and others may have thought you were using the ori sensor in a larger housing instead of using a whole MAF assembly already in use from Bosch for the 1.8t motor in the S3/TT225. If you have copied the stock values from the file that had the larger OEM maf you will be just fine and should be able to count on your g/s values being accurate.