My Ferrari garage just mounted a pair of BMC filters on my 456M GT, and I can feel that the engine behaves differently. On one hand it is running smoother than before, on the other hand when I give full throttle in 6th gear from around 3000rpm, I notice that the car is not pulling as much as it did before with the paper air filters. When I switch back to a lower gear, it pulls like hell. Is it possible that because of a less restrictive air flow the mixture is getting a bit leaner, and if so, why is this happening. The MAF sensor measures how much air is sucked by the engine, so more air should result in more petrol being delivered by the ECU. Or is it the extra fuel needed when accelerating that should be increased ? Any comment would be welcome. P.S. I have planned to replace the middle muffler by two straight pipes, and then to have the care tested on a rolling road. The BMC filter was the first step.
