NefMoto

Technical => Diagnostics => Topic started by: tkla on February 13, 2025, 05:51:40 PM



Title: S4 B5 Trackday car fine tuning Help
Post by: tkla on February 13, 2025, 05:51:40 PM
Hello, my project car is an Audi S4 B5 2001.5 stage 3
I did an upgrade to 1000 CC Bosch 0280158117 injectors and now I am not achieving the requested boost. This car is a trackday car, so I removed almost everything for the car.
I pulled a couple 2nd gear logs due to traffic, however it reflects the same behavior as in 3rd gear.

IMPORTANT MODS (The car has more ask if you need something else please)
M BOX
EV14 BOSCH 1000 CC INJECTORS
RS4 MAF HOUSING (Hitachi)
ALTTITUDE 2400 METERS ABOVE SEA LEVEL
WEATHER 25 CELSIUS.
AEM WMI
PUMP GAS 91 OCTANES.
RS6 K04-25 TURBOS.
ABD MODULE REMOVED.   VCDS Soft coded
N80 REMOVED However N80 wiring DTC is present.
OE Engine

Attached find logs and current Map if you could help me I will appreciate it a lot



Title: Re: S4 B5 Trackday car fine tuning Help
Post by: nyet on February 13, 2025, 05:56:47 PM
log all PID variables.

If i had to guess, your WG's are set too soft and you'll have to modify KFLDIMX and/or KFLDRL accordingly. Consult the tuning page.


Title: Re: S4 B5 Trackday car fine tuning Help
Post by: prj on February 14, 2025, 04:00:35 AM
RS6 K04-25 TURBOS.
OE Engine

Bent rods in 3... 2... 1...


Title: Re: S4 B5 Trackday car fine tuning Help
Post by: nyet on February 14, 2025, 04:05:50 AM
Bent rods in 3... 2... 1...

Not with his wastegates set where they are ;)


Title: Re: S4 B5 Trackday car fine tuning Help
Post by: tkla on February 14, 2025, 03:31:14 PM
Thank you for your quick response!
I did a slight mod in KFLDIMX and/or KFLDRL.
Here is a log with PID variables, if there is something more to log let me know.




Title: Re: S4 B5 Trackday car fine tuning Help
Post by: tkla on February 14, 2025, 03:34:48 PM
In Action


Title: Re: S4 B5 Trackday car fine tuning Help
Post by: nyet on February 14, 2025, 04:00:09 PM
100% wgdc and 13psi isn't so hot.

something very wrong with your setup.

bad n75, wg not adjusted etc.

hopefully not a boost leak.


Title: Re: S4 B5 Trackday car fine tuning Help
Post by: tkla on June 01, 2025, 08:44:57 PM
I just changed my wastegates with stiffer springs, no boost leaks no vaccum leaks. Maybe my MAF table is not calibrated I did a new log and my highest MAF values is 205 g/s
Any help is more than welcome




Title: Re: S4 B5 Trackday car fine tuning Help
Post by: nyet on June 03, 2025, 12:01:18 AM
That looks absolutely awful. The issue is hardly MAF related. Did you even look at your boost req vs actual and WGDC? I have no idea what you think you are doing, but you seem to have ignored the entirety of the s4 tuning page. If your wastegates are good those turbos are toast.