FPV DECIMATED the HSV!

[Sorted]

Originally Posted by Bent8

Regarding driveline losses, there was post from another thread were it was clearly explained that percentage losses are inaccurate because a car will only lose so much power through it's drivetrain regardless of rear wheel outputs, but I averaged out the kW loss for both cars and came up with..

GTS = 116kW power loss
GT-F 71kW power loss

From this we come to the conclusion the GTS drivetrain robs around 40% more power than the GT-F's setup... so either the GTS drivetrain is extremely inefficient or HSV are overstating power outputs (again).

And I would expect the HSV to have higher torque numbers as we should all remember we are comparing a 5.0 with a 6.2

God this is a first and I will regret it but Rodge touched on this here

Originally Posted by Rodge

Its a black art and steeped in a lot of theory and mystery.
I searched a lot of interesting literature on the subject...there's an awful lot to it.
Even the size of the wheels can have quite a significant effect on rwkw's due to the extra centrifugal force required to rotate a bigger mass.
Tyre slip is another huge area and the size of the diff and losses therein can vary widely.
Transmission losses can vary significantly and as mentioned the ZF is extremely efficient whereas the heavy duty unit is the GTS less so.

I think there's quite a bit in this the following area's
1. IIRC The GTS engine had only done about 1800 km's so was fairly green whereas the GT-F engine had about 8,000 km's on it so was probably fully run in. I think this factor alone could account for 2-3 % as a best guess of the power discrepancy.
2. GTS is running 20 inch wheels = more centrifugal losses from greater rotating mass
3. GTS transmission is best guess 2% less efficient than the ZF box
4. Bigger diff probably soaks up another one or two percent at least

Add it all up, you do the maths but seeing as we're talking about a less than 6% peak power difference between the cars on the Mainline dyno all Im saying from a technical perspective it would be good to see them reevaluate this test with 2 manual cars that have both done about the same km's to see the difference then.

Then there's the fact that the GT-F was a dedicated press car from the outset...not saying the engine was blueprinted or had a special tune but one can't rule that out seeing as they knew it would be a press car but the fact that its been belted really hard as a dedicated evaluation vehicle from the get go is possibly to its advantage in this comparison.

Originally Posted by devoGT

But the GTS times are mighty impressive 4.2 and 12.1, I don't think any stock GT has come close to that auto or manual in magazine reviews.

And yes 12.1 is fast - unsure if a Stock FPV GT has done it but if it has it may be in this thread http://www.fordforums.com.au/showthr...328022&page=50