Well having driven it about for a day I'm am very pleased. The engine seems a lot smoother all over, also very quiet during cruising. The ignition map is totally un-tuned too. Once you ditch the AFM you really notice the pickup of the engine is much better. Its neck snapping now when you stamp on it as fast as you can in 1st gear. The car doesn't jar or anything it just launches

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I also switched to a fixed fuel rail pressure, which has given a nice improvement as one of the results of removing the AFM is that the MAP increases much more rapidly as the AFM was almost like a pressure change damper (almost a throttle really). You can see the vacuum it creates by blipping the throttle in the engine bay and watch the intake boot shrink due to the vacuum. The negative impact of the fast changing MAP is that the fuel rail pressure regulator can't keep up with the MAP changes. It's trying to maintain a 2.5 bar differential with manifold pressure (rising rate). This means you can burn lean if you stamp on it as the fuel rail pressure is momentarily low and you get less fuel than you think. Now that the fuel pressure is fixed I no longer have that to worry about and the throttle response on my 944 is awesome and its not even been mapped properly

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