Turns out the GTR does make 480 HP!

[gt_performah]

http://www.motortrend.com/features/p...est/index.html

Okay that is one mystery solved so to speak. Now onto why there is a discrepancy on the ring numbers and my life will be complete.

[GZire]

OK, how does it calculate parasitic losses? I haven't seen anything that addresses that.

[alphamatt]

the gtr's performance affects your life that greatly?

[gt_performah]

Originally Posted by alphamatt

the gtr's performance affects your life that greatly?

That's how I feel today, but tomorrow it will probably be something else that affects my life.

[pattyskin]

Originally Posted by GZire

OK, how does it calculate parasitic losses? I haven't seen anything that addresses that.

So, how did Hyper Power USA measure our driveline drag? At the end of a pull, the computer instructs the operator to put the vehicle in neutral, the dyno then measures the rate at which all the rotating parts slow down, which is directly related to friction and inertia. Our instruments found the loss to be exponential -- as the speed grew so did the loss. We saw a loss of 23 hp at 50 mph and 84 hp at 100 mph. Over the three runs we saw a driveline loss range from 88 hp to 93 hp. Thus, there is no longer the need to guess at a percentage, Hyper Power Dynamometer's DYNOmite measures it and gives you an actual figure generated by the engine and consumed by the driveline

[jaspergtr]

i don't this addresses the whole picture, although this is a great solution to aleve some of the myth...

that means at below 50mph, my car delivers around 460whp? doubtful.

they don't dyno in all gears. and in neutral, no gear is engaged. so this doesn't account for the entire driveline, just the parts after the gearbox.

[GZire]

Originally Posted by pattyskin

So, how did Hyper Power USA measure our driveline drag? At the end of a pull, the computer instructs the operator to put the vehicle in neutral, the dyno then measures the rate at which all the rotating parts slow down, which is directly related to friction and inertia. Our instruments found the loss to be exponential -- as the speed grew so did the loss. We saw a loss of 23 hp at 50 mph and 84 hp at 100 mph. Over the three runs we saw a driveline loss range from 88 hp to 93 hp. Thus, there is no longer the need to guess at a percentage, Hyper Power Dynamometer's DYNOmite measures it and gives you an actual figure generated by the engine and consumed by the driveline

So at 200 mph we can assume the drivetrain has at least 168 hp in losses (more accurately it's probably way north of 200 hp)?

23 hp @ 50 mph
84 hp @ 100 mph

I'm trying to wrap my mind around the losses formula, but an exponential loss with increased speed seems correct on one hand, but weird on another. In other words the faster you go at some point you will have less hp actually reaching the road than at a slower speed. It doesn't seem right to me.

[GZire]

Originally Posted by jaspergtr

i don't this addresses the whole picture, although this is a great solution to aleve some of the myth...

that means at below 50mph, my car delivers around 460whp? doubtful.

they don't dyno in all gears. and in neutral, no gear is engaged. so this doesn't account for the entire driveline, just the parts after the gearbox.

Vehicle speed in addition to engine rpm is what determines what power you are making. The whole determination of drivetrain losses is confusing.

The engine needs to go on an engine dyno.

[Texasscout]

Originally Posted by jaspergtr

i don't this addresses the whole picture, although this is a great solution to aleve some of the myth...

that means at below 50mph, my car delivers around 460whp? doubtful.

they don't dyno in all gears. and in neutral, no gear is engaged. so this doesn't account for the entire driveline, just the parts after the gearbox.

Good question? In a normal MT if the trans is left in gear and the clutch disengaged, then parasitic losses would include all the gear train. You have no way to "disengage" the clutch(es) in Godzilla. So when you put it in neutral, you might not be getting the full loss.

As for your power at 50mph, it would depend on throttle position, RPM and what gear you are in at the time.