May, 1997 on Commodore VR V6

WHIRLING SENSATION

It sounds like science fiction. You grab a shiny metal ring which has got a whole lot of vanes mounted in it. You undo the hose clamp of the intake duct straight after the air cleaner, insert the device the right way around, and the do up the clamp again. You've just gained four hp at the back wheels - probably a bit over five at the flywheel! So what the hell is the story?

Anyone who tells you that dyno testing is straight forward hasn't done any testing. Even with the temperature correction probe in the air cleaner box inlet, Consecutive dyno runs usually vary. In fact, over four runs it's not at all uncommon to see peak power variations of five per cent. To prevent false results clouding the issue, We averaged the power curve from both ramping upwards an downwards - something I've not seen other people using the same brand dyno bother to do. (This takes into account the rolling inertia of the dyno itself.) And secondly we keep pulling power runs until the curves draw over themselves - the power being stabilised as much as possible. Without the Hiclone in place the power curve stabilised at 115hp at the rear wheels. Incidentally that shows how strong a engine the standard V6 with extractors and an exhaust really is! But, while the standard engine's peak hp figure was 115, one pull resulted in a 121hp peak! See how easy it is to rig the results?

With the Hiclone in place the first run gave a peak of 117hp (2 up over standard), before the power stabilised at 119hp. 119hp is four more rear wheel horsies than standard and assuming a conservative 23 per cent drivetrain loss is just over five hp at the engine. The power gain started from 80 km/h in second gear and remained a consistent three-four hp from there up. Ken was driving his car on the rollers. Leon was averaging the ramp-up and ramp-down graphs on the computer screen. I was looking incredulously at the screen - a power gain from that tiny little thing!!?

On this VR Commodore, standard but for extractors and a 2.5 inch exhaust, the correctly-mounted Hiclone gave a peak power improvement of 3.5 per cent, without losing any power lower in the rev range. The Hiclone cost $175 fitted, which works out to about $35 per horsepower. The Makers also claim improvements in fuel consumption, emissions and engine smoothness.