Originally Posted by tscdennab
This is just another disguised tuner bash. For whom may be interested, I have done some testing on a private road a few days ago with a friend's car which has a JB4 (he used Map 7). I have GIAC Stage 2.
The ignition timing was almost identical between my GIAC Stage 2 pump and his JB4 map 7. We compared the excel files in detail after the runs, we did graphs. Nevertheless he beat me but I have fewer mods
I will ask for his permission to post some of the graphs.
Conclusion: the N54 ECU is not a Subaru ECU: it is more advanced. The knock sensors and knock ADAPTATION work very closely to ensure proper timing. At least from what I have seen, and I have seen hard data with back to back runs, not just talking and bashing.
This maybe true. The difference is, JB relies entirely on "riding" the knock sensor and the stock DME to adjust for anything that gets thrown at it.
Whereas, GIAC/Cobb, any other flash tuner, re-writes those ignition timing tables to take into account proactively, the additional boost/load demand, all tested on the dyno...to avoid relying on bouncing on the knock sensor and DME to "REACT".
There is a huge difference between using the knock sensor as a fail-safe/last ditch security mechanism, and RIDING it all the time and relying on it to adjust timing.
This is 101 FI tuning fundamentals. You need to control timing to avoid detonation at all costs...or engine goes boom....that simple.
But I agree, it is more a tribute to how well BMW designed/developed the stock knock system and DME logic to save its ass over and over with some tunes....