Dyno daze

The Aussie muscle car world shifted on its axis just a little on July 9. In a dimly lit dyno cell in the Melbourne suburb of Springvale, the unexpected took place: Ford Performance Vehicles' GT F out-powered the Holden Special Vehicles GTS.

FPV’s 351kW beat HSV’s 430...

We didn’t expect the result. Judging by the comments neither did you — and you said so.

Rarely, in almost 25 years of auto (and allied) media, have I seen such a mix of feedback. Some was logical and measured — some was childish venting... I’m Red, you’re Blue — therefore you’re wrong... And vice-versa.

Some went (almost) as far as to suggest our results were fraudulent.

Australian muscle cars might have grown up (as evidenced by these two remarkable supercharged V8 sedans), but some of their fans have a long way to go.

We chose our dynamometer for two reasons: one, we’d used the crew at Springy Performance before; and two, the operation had no vested interest.

The equipment, a Dyno Dynamics 450-DS AWD electronic brake dyno, is typical of the equipment used around the country and delivers consistent, repeatable numbers.

Heat is the enemy of power on dynos and as such we were careful. The Springy Performance crew kept the big fans on max and we let the cars idle with the fans on between runs. As is convention, all runs were made in fourth gear (in most six-speed cars fourth approximates a ratio of 1:1, which keeps power figures as accurate as possible).

The HSV went first and pumped out four ultra-consistent runs between 338.1 and 339.6 rear-wheel kiloWatts.

Then the FPV...

Given there are 335kW RSPEC GTs out there with close to 310kW at the rear wheels, we expected the GT F’s output would be a lot closer to the HSV than the advertised figures suggest.

Indeed, FPV insiders hinted at the car’s launch that they expected the GT F’s real-world power to be close to the number suggested by its iconic 351 badge.

When the first run yielded 343.0kW we were surprised. When two subsequent runs showed no drop off and indeed edged higher we were even more surprised.

In the end we ran the FPV nine times. Not to maximise the numbers (the best run was the fourth or fifth), but rather to make sure nothing was amiss.

The GT F variously logged between 343.0 and 348.6 rear-wheel kiloWatts. At the risk of shortchanging the Ford 0.7kW, the graph we’ve published here is from the corresponding (fourth) run to the HSV’s best.  

Max boost measured on the FPV was around 9psi -- 0.5psi higher than the HSV. As far as we can tell, nothing was amiss with the HSV and nothing was out of the ordinary with the FPV.

As is always the case, maximum power is only part of the story. What’s clear from the dyno is that the HSV is a powerhouse right the way through the rev range, while the FPV builds power in a more conventionally shaped power curve.

Compare the graphs here and you’ll see it’s only at above 6000rpm that the FPV betters the HSV.

At 3000rpm the GT F delivers around 175kW — impressive. But the GTS has 195.

At 4000rpm the HSV has 256 — over 10 per cent more than the FPV (about 230kW). The intercooled HSV’s extra capacity is telling. Indeed, between 3000 and 5250rpm the GTS' advantage is typically more than 25kW.

It’s a similar story in terms of maximum torque. At 3000rpm, the HSV has around 720Nm at the rear wheels and there’s over 700Nm available all the way through to around 5500rpm.

The FPV’s torque peaks at around 6000rpm at approximately 720Nm. However, in contrast to the GTS' slow moderation of torque, the GT F rises to its peak gradually from around 630Nm at 3000rpm.

The FPV may have more peak power, but ultimately the HSV's superior power across a wider rev-range (and more torque everywhere under about 5500rpm) ensures it is dominant. And just as importantly, as you’ll read hereabouts, it can put that power to the road... And track...

Ford Performance Vehicles GT F
Max power: 348.6kW at the rear wheels
Max torque: 721Nm at the rear wheels

Holden Special Vehicles GTS
Max power: 339.6kW at the rear wheels
Max torque: 751Nm at the rear wheels