I replaced my 2.8 air mass with a 2.0 unit and using a g-tech meter, managed to shave off almost 1.2 secs for the 0-60mph time. I managed to clock 8.6s (M52 engine block, ported head, 5hp-18 ZF tranny) in my e34.
Is this due to the venturi effect?? Smaller diameter, quicker air velocity??
Rgds
Albundy