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Old 09-13-2006, 12:14 PM   #21
Join Date: Feb 2002
Location: Stance
Posts: 13,107
Thank you for adding to the information posted.

Alpina, and other German tuners did indeed build stroker motors using the stock injectors, but from what I understand all changed the fuel regulator, increasing the fuel supply.

While admittedly my personal motor had likely tired injectors during my dyno session, they did CLEARLY move into "wide-open" when combined with software changes (Mark D'Sylva). With the stock chip, the AFR ratio was almost perfectly stoich through the RPM range.

You seem to be a knowledgeable person, therefore I'm sure you must have come across the simple mathematic formulae used to calculate possible power from a fuel injector. Using these, at 80% of the injector's duty cycle (the highest use generally recommended) a stock M20 injector can only make ~140hp. Using that number and calculating further, one will find that BMW is actually running the stock injectors at 96% of their duty cycle, in a bone stock M20B25. A 14.6lb/hr injector combined with the stock 3.0 bar regulator can only physcially make 175hp. This is simple physics, it's impossible to argue with.

I hope this is sufficient proof for you that stock M20 injectors are too small to add any sort of modifications to the motor and actually gain power.
Mystikal is offline   Reply With Quote