[il-mostro]

Hi folks. Here is a little question that somebody might know the answer to? Here goes.......

Mr Clarkson once said on 'Topgear' (i think?) that the Supercharger for the Merc/MacLaren SLR uses 126 BHP to operate it alone!?

Does anyone know how many little Ponies are used to spin up the S'charger on a standard MCS?

Just thought i'd ask.......get your thinking caps on.

Ta ta.

[St00ge]

i think he said 120 bhp to start running it.

http://www.automotive.eaton.com/prod...argers/M45.asp

look at the second graph, that's all i could find

[MINI-Morgan]

Interesting thought.....I think most of us would be just putting our finger in the air and guess really. I think its around 30lb/ft of torque to turn it. But then reduce the pulley size and that goes up but the engine produces much more power.

[Andy@Ross-Tech.com]

Actual airflow through the engine is a pretty good indicator of the amount of horsepower generated before accessories come into play. 0.80 is a decent rule of thumb for the ratio of bhp to g/s of airflow in a street engine. For instance, a 250 bhp Audi S4 2.7T flows about 200 g/s (grams of air per second). The MINI doesn't use a MAF so it doesn't directly measure airflow, however it does use a speed-density system that calculates airflow from rpm, IAT, MAP, and the volumetric efficiency of the engine. Anyway, the DME spits out airflow values to the factory diagnostic tools. On my MCS with a 15% pulley, intake and exhaust, the dyno showed 173 whp (144 whp stock). That's a shade under 200 bhp by most calculations. Airflow was very similar to that of the stock S4 (around 200 g/s). So, it looks like the supercharger consumes around 50 whp at WOT and 6500 rpm.