throttle body/blower questions

[lance1a]

Hi, Dibilas sent me the wrong cam for the M10 (clockwise instead of anti) so that's back in the post, and will be for the next three weeks. In the meantime I bought a G reg 320i touring to mess about with. Having a look at the throttle body subject and the conversion from 2.0 to 2.5L TB's, why can't I use the old TB from my 1.8i? or am I stupid in thinking that the TB from the 1.8 is bigger than the 2.0 considering the number of cylinders the airflow is divided amongst?
If this is the case I might be able to rig my unsold cooper 's' blower to this motor as supercharging the fuel injection motor is not as complicated as trying to force feed the bike carbs on the M10. Just a day before I was due to scrap the 320i (with a newly rebuilt motor) I used as a donor for my 316, the Touring came along for beer money but the motor is a bit smokey. So the bent 320i is still offering up valuable parts! Easter's around the corner with plenty of time off, so might be a good project that costs nothing.