MCS more fun in the cold weather

Posted by murmini Wed, 30 Nov 2005 19:34:00 GMT

If your driving a Mini Cooper S and your sensing a little more 'oomph' in this cooler weather, your right. The main reason for the increase in power in cold weather is due to the increase in air density in the Roots/Eaton supercharger.

When it's hot the air molecules are more active and subsequently take up more space, hence less density which essentially means there is less oxygen per cubic metre of air, compared to a cold day where the air is more dense. So warm days affect all combustion engines in cars, but if the car is supercharged then matters are made worse. In addition to this, the intercooler is much more efficient on a cold day and the air is made even cooler and more dense. So what this means is; cold day = faster MCS, warm day = slower MCS. So I wanted to actually gather some info as to if this was just science or if it really had some measurable effect and found these numbers published by Mike Cooper of John Cooper Works.

 C   F   bhp
 0  32  212
 5  41  209
10  50  206
15  59  203
20  68  200
25  77  197
30  86  194
35  95  191
40 104  188