My limited understanding of the fuel injection system is that it will detect the add'l intake air from the super charger immediately upon startup and begin to adjust the injector and engine timing to balance the inputs from the MAF and the O2 sensors. Additionally, I thought that it took about 10 mins of running for the Motronics to "learn" and store an updated map in the ECU.
If you experienced a hole in a piston, this seems to imply an extreme detonation (knocking) condition which shouldn't normally happen with knock sensor and O2 feedback into the ECU. However, it seems like it might happen when running with a new supercharger (more air) with the stock injector maps (same fuel) which could create a super-lean mixture and thus, create an extreme detonation condition.
Based on this, it would seem most prudent to start with a proven and tested ECU map that is customized for your supercharger and the 2.5L engine. This way the ECU injector and ignition timing will be very close to optimal from the start and the risk of detonation and engine damage would be reasonably low.
However, if you don't want to do this or can't, then it would seem prudent to start up the engine with the SC installed and drive it gingerly (less than 2,500 RPM with minimal load) for about 20-30 mins to let the engine warm up and once warm, allow time for the ECU to adjust the mixture/timing for low speed operation with the new supercharger. Seems like the worst thing to do would be to jump on the gas hard at this point or the engine might instantly go very lean, knock severely, and possibly damage something (which could all happen in just one hard run up to the redline).
Then stop and let the engine cool to ambient temp (it doesn't have to be cold) and then repeat while driving around at low and medium engine RPM's and loads (up to 3,500) for about 20 mins to let the ECU re-map to mid-level operation.
And repeat once again for higher RPM operation (5,000 rpm). Then one might want to attempt a run up to near redline (6,000 rpm).
Of course, you would have to re-perform this learning sequence again anytime that the battery was disconnected (which clears the learned ECU maps).
I cannot say that this procedure is proven but it makes sense based on my understanding of the Motronic fuel injection system. I welcome any thoughts or inputs where I may have missed something or got it wrong.
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1999 996 C2 - sold - bought back - sold for more
1997 Spec Boxster BSR #254
1979 911 SC
POC Licensed DE/TT Instructor
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