Edmunds was gracious enough to be the 1st publication to share their results when they snuck a 5.0 to a Dyno to test Fords 412hp claim. Looks like Ford is delivering us Mustang fans a 5.0 that is every bit as worthy of the predecessor and the Mustang heritage.
Excerpts:
You see, the Mustang GT's newfangled all-aluminum DOHC 5.0-liter V8...it makes some power. A lot of power, actually.
Peak numbers are 365 lb-ft of torque at 4,350 rpm and 395 hp at 6,600 rpm. All of these at-the-wheels figures were obtained in 4th gear on a Dynojet 248 chassis dyno and include a 3% SAE weather correction factor.
Driveline loss for a solid axle-equipped car like the Mustang is typically 11-13%. This is a bit less than the usual 15-18% you'd expect on an IRS car, as solid axles have fewer power-sapping U-joints in their driveline. Hence, we should expect to see about 358-367 rwhp from this car.
There was some controversy on the gear that Edmunds chose to use for testing. One of the readers commented that the numbers were too exaggerated since they didn't use a 1:1 gear. I present to you both arguments. You can decide your own opinion.
rrocket says:
08:41 PM, 03/24/10
Ummmm.....no wonder why the HP was higher than expected, you knuckleheads dynoed it in the wrong gear! As per Ford, 4th gear ratio is 1.32:1 Everyone who runs a dyno knows you should dyno with a 1:1 ratio, which in this case is FIFTH gear. Doh!!!
The Dynojet itself doesn't care what gear the car's in. Remember, there's a final drive gear reduction after the transmission, which further alters the wheelspeed - engine speed relationship beyond what the transmission does, so there's nothing magical about 1:1.
In fact, dynoing in a gear that's 1:1 usually results in a hair less (yes, less) driveline loss as its a more (the most) efficient ratio in the gearbox. That's why a lot of dyno operators like the 1:1 ratio. Plus, when using an inertia dyno like a Dynojet, higher gear ratios have a lower rate of acceleration, so less power is soaked up in accelerating the rotating masses, which further props the numbers up.
Higher gears do tend to result in higher tire losses since the wheelspeed is higher... at this point all you're doing is trading off one loss mechanism for another. Generally, though, what I've seen come out in the wash is that on an inertia dyno, higher gears will result in higher numbers than lower gears.
Furthermore, higher gears also load the engine for a longer duration, requiring more cooldown, plus put more heat stress on driven tires. As the dyno operator, I don't like either of those things.
But one thing is for sure, the 2011 GT will produce more power than the claimed 412hp and 390 lb torque. While weighing hundreds of pounds lighter than the V8 Camaro and even the V8 M3. This is going to be one unforgettable summer for us who are awaiting delivery.
