NefMoto

Hi guys, i have tuned my Audi S3 tfsi stronic with a step 1..the car run faster and quite smooth with no particular issues but i dont understand well the management of the pressure...now the boost peak is about 1.4-1.5 bar and it keeps 1.3bar till  about 6000 rpm and then  at 1 bar or less at rev lim...i can't manage to raise the pressure after 6000 rpm and sometimes it drops to about the stock pressure (0,8 bar) at 6600 rpm...i logged many parameters and it seems to be all ok apart of the actual engine load that decreases below the requested on kfmirl and the load 'cap' LDRXN...concerning boost pressure i changed the following maps: KFMIRL/-S and the 'inverse' KFMIOP/ -S, KFTARX and the closest maps limiting the pressure according to IAT,KFFLLDE , KFFWLLDE, KFFLDEO, KFFSLDE, pressure ratio KFLDHBN,LDPBN, KFLDIMX,  LDRXN and LDRXNZK...Have i missed any map to raise the pressure at high rpm?...the lamdba values follow well the requested setted in lamfa maps (BTS protections disabled), pressure rail ok and even injection advance with timing retardations always less than   3 degrees...i appreciate every help thanks:-)

What is wastegate duty cycle?

I believe I'm experiencing the same issue. My factory ldrxn dropped down very low after about 6k. I've raised everything that I thought would limit this but boost still falls to almost nothing over 6k. Interested to see what people have to say.

I didn't log duty cycle but i guess it's not a wastegate problem because the requested pressure drop according to the load...imho a duty cycle issue should imply the actual pressure doesn't follow the requested ...it seems something is missed in my tune to request more boost at high rpm...
further looking at other tfsi logs online, sometimes the same actual load request more boost than mine and it's strange, logically i mean loads under 191 that is the limit shown in logs; as there would be a different load/pressure convertion factors...

Can someone help me?is there a limiter map for boost at high rpm or something else limit my load?...i attach a log where you can see the load fall to about 170 at 6500 rpm whereas i set 190 on LDRXN changing also all the other limiter maps previously mentioned....

First please load you ori file, or write bosch numbers.
Can you try to reduce your igntion and see will there be difference.

Do you mean reducing ignition advance the boost pressure should raise?it seems strange, even because i don't have excessive timing pull that may activate a sort of protection...i attach the original file and an original log just done, interesting is the AFR stock that is already very rich at high rpm due to BTS maps actived...i thought stock AFR was leaner...

Can stock turbos on the DI motors hold 1 bar to redline? The 1.8t k03 is really struggling at that point.

2.0tfsi with K04(OP says S3) should be able to hold 1.1-1.2 bar at redline.

I have seen logs with k04 holding 1.5 1.6 till over 6000 rpm and 1.2 1.3 at red line...maybe is the limit for power gain keeping  good reliability...that's not my point because i don't have the hpfp but   manage to request more load after 6000 rpm...soon i will try another file with KFMIOP axis better scaled to match KFMIRL maximum load and i gonna check if the load raise...

It's probably holding 1.6bar because the inlet is chocked up.

Not with stock hardware.

...what is it required to replace?..tightening of wastegate or a stiffer one?...interesting subject but is about not matching requested/actual pressure..my problem is still to request more load at high rpm :(...

Can you log also intake temp and engine temp ?

Yes but i have my stock fmic enough efficient for k04 achievable pressure...i did a log with stock file where IAT doesn't go beyond 30 degrees at wot with an external 10°....and i set the KFTARX maps all at 1's to avoid IAT based correction of  boost pressure....actually i found  discussions in other forums regarding the difficulty in achieving more boost at high rpm in MED9 managed engine and the inability to deceive this issue of many well-known tuners...

You just seem to want to take this turbo out of its efficiency range.

go ahead and crank the wastegate or get a forge unit, you will hold 1.4 to redline i bet at that point.

now go log your iat's after a few wot runs.

This is  about as much as you will get on K04.  And look how the temps are rising quickly, and this is with a much bigger inter cooler than std.

Rick