Just for fun, it would be interesting to see what you think the effect is going to be.
The last time it was on the rollers it made 265bhp @6300rpm and 245lbft at 5300rpm on standard cams with 12psi of boost.
All that has changed is the cams, the supercharger pulley and everything else is as it was at the last run.
My thinking is this:
The supercharger pumps a certain mass flow of air at a given RPM and pressure ratio. Therefore with the old set up it was pumping 0.36kg/s of air at a PR of 1.8 bar.
The new cams are mild road cams, with slightly higher lift on both than standard (exhaust increased significantly) and much longer duration, therefore there is now some level of overlap as well, where there was virtually no overlap with the original cams. The cams are the 210bhp spec ones from raceline/caterham so would give a 20bhp increase in power on a standard engine with no blower.
Assuming the supercharger RPM is the same (which it is) and the factors above will cause some pressure ratio decrease. An increase in air flow will also give a PR decrease. But a slight increase in mass air flow.
Therefore my prediction is that power will increase slightly over what it was last time, with a decrease in PR and a shift of the power up the rev range and a corresponding decrease in torque at lower revs.
Out of interest, what think you? With your reasoning too
