AUDI RS2 hesitation with chip

[turbo20v]

hi!

i have quite strange problem on my audi rs2. If i use stock ECU it works perfect.
Furthermore if i use chipped ECU from one tuner it works perfect to (caa max 1.8 boost). But if i use chip from other tuner with similar boost profil and target hp/nm there are some hesitation at WOT at 3th and higher gears at about 5200rpm. At those rpms boost drop to only 0,5bar but then raises again back. Timing is also retired back .......
Any ideas what should be wrong ?

ps: Booth chips are from good tuner.

[Jamo]

Your using generic chips not setup directly for your engine, the one that hesitation sounds as if the timing is too much and inducing knock, do not use it.

[EspenW]

Yep, sounds like knocking.
Can you post the 3rd gear WOT log showing the timing data? (I assume that you have that as you mention that timing is pulled)

[turbo20v]

Yep, sounds like knocking.
Can you post the 3rd gear WOT log showing the timing data? (I assume that you have that as you mention that timing is pulled)

well i did it in 4 gear. There is one log

[EspenW]

Thanks. Timing jumps from 12.8 at 5040rpm to 27.8 at 5400, then back to 15 at 5640.
That would explain some funky behaviour.
Ignition pull is the first line of defense, then fuel is dumped, and then boost is pulled if knock still persists.
Note that injector duty cycle drops right at 5400rpm as well.
Your battery voltage is rather low, starts at 15v+, but then drops to mid 12v range. Nothing exceptional, but fuel pump, etc. could benefit from somewhat higher voltage.


I would send the log to the tuner and get their comment, but I'm sure that Dimitri or Paul will have some good input as well.

[EspenW]

Here are the power and torque curves. Note how the power goes flat for a few hundred rpm at 5000rpm.






NB: the shape of graph is representative, but the numbers are just a guideline as weight is estimated and the pull could have been made on a road that wasn't flat. In addition, ambient temp, etc is unknown.
Logging just one group would give better resolution that might pinpoint things further.

[turbo20v]

thanks EspenW ! Well i will sent logs to tuner and i hope he could fix that problem. I will let know what will hapend !