I'm trying to work out what boost and therefore the power gains i will get from putting an eaton m45 on my 1.8 zetec.

Anyone know the diameter for a zetec crank pulley?

Thanks
Chaz

No but if you've got a 1.8 zetec I can tell you the size of the M45 pulley

Working out boost figures from pulley sizes is very rough estimation only as well. The chance of getting it spot on first time is minimal due to the fact that boost isn't just a question of blower speed, it's connected with lots of other variables...

As Ben says boost is a measure of the pumping ability the blower plus the ability of the engine to breath that air. So many factors combine to produce the measured PSI reading.

Reading a book like "Supercharged" by Graham Bell will provide some simple calcs to estimate your pulley sizing.

if you go on the eaton site theres a compressor map on there for the m45 then just use a java calculater like these to work out your compression ratio although this will be a bit arbitrary with a m45 on a 2 l but theres a power output calculator on there the most important bit is going to be to match the charger rpm to your torque curve so you end up with a more liniar output