[Shiv@Openflash]

Originally Posted by DeliciousTuning

Mercedes and BMW uses Manifold Air Pressure (MAP) on most all of their turbo engines, not MAF. And we all know how BMW and Mercedes drive, nice and smooth in all conditions. If an OEM can do it, than I am sure with EcuTeK and RaceROM custom mapping we can do it.

Speed Density works very well once tuned in, but yes it needs to be tuned in and that does take time. Once you have nailed it, there is never a need to rescale the MAF sensor for different size pipes, just drop in the tune and and go. Makes tuning a little easier at the end of the day if you put the leg work in up front.

So on systems that come with blow-through MAF systems, I prefer to run a 100% Speed Density setup, as it will make for a much more consistent tune versus running a blow-through MAF. The idle will be rock steady, open/closed loop conditions will be consistent and cruising can be dialed in nearly perfect and then reused on many applications.

At the end of the day us tuners all have our own opinion, so choose your tuner and go with what they recommend to make sure you get the type of tune you are looking for. Personally I would only recommend Speed Density on vehicles running forced induction setups that do not offer a draw-through MAF system. In these applications Speed Density will be ideal for a much smoother and more desirable tune in my opinion.

Cheers,
William Knose

BMW uses speed density on it older turbo engines because it operates closed loop fuel control 100% of the time. So there is no risk of missing fueling targets under any load conditions. I'm not certain, but I think the same applies to Mercedes as well. So I don't see how that is relaven to our platform which transitions to open loop fuel control under load. And that is an NA application. Errors are multiples when boosting on top of that.