Golf MK7 R MQB Simos 18.1 Stage 4 / HELP

[zReeDx]

Hello guys, I am in need of help with my Stage 4 Tune for my Golf 7 R.
I had my hands on a perfect file for my engine and car, but the guy gave up.

Car runs heavy but is having still the issue in high rpm.

i want 550-600hp and 650nm.

I changed:
upgrade turbo until 2.5 bar boost - bigger GTX3071R
Downpipe 3?
Intake - APR Carbon Box
Intercooler
Ignition coils and igniters
980ccm MPI injection
LPFP Stronger
HPFP - 8mm piston to 11mm

And inside of the engine i changed all valves, pistons, rods and everything available in the market.

I am testing and making and doing and got everything working.
I am tuning my car with HPTuners software, and works pretty good. Calibrating of MPI Injectors and Big Turbo is no Problem. All Adresses / Maps are in the Software.

But I am having misfiring issues at high rpm. As soon as I reach 5500rpm, it starts to misfire. Not strong, but very few.
I noticed that when I run the Power enrichment and target lambda of 0.89 - the misfires are very very few. Like 1-2 misfires in one pull.
When I change it to 0,85 lambda, it?s starting to misfire at 5500rpm pretty heavy.
All problems start at 5500/5600rpm and continue until higher rpm.
With lambda 0,89 is nearly no misfire, but with with 0,85 there are sometimes heavy misfires.

In the log is no issue why it?s misfiring. It?s knock retarding until max. -1,5degrees on very few a cylinder.

I am trying to advance and retard the base maps, nothing is helping.

I need big help please.
I am offering 300? for the guy, who help me and fix the problem.

Please help guys!
I tried now many times and many different things.. and don?t know what else to do.

Spark plug gap is 0.22.

Looking forward for your reply

[GCtech]

Who?s stage 4?

[Diesel_Enthuse]

Hi zReeDx,

is your rail pressure sufficient to feed the increased injector size in the optimum injection 'window' and is your injection timing optimized? It is possible your pulse-width is too great at current rail pressure, hence the slightly 'less rich' 0.89 lambda has less misfires. Experiment with slightly higher rail pressure and 0.89 lambda to see if misfires completely stop?

I'm not even nearly an expert on the Mk7 platform but that is what seems obvious to me

[TheDrill]

I had similar issues with a b5 s4 using platinum spark plugs, I changed them out for cheap NGK BKR7E copper core at 24 thou and it fixed the issue.