The guys over at 5.0 Mustang & Super Fords are always eager to find the true horsepower of a car, and so when they took delivery of a GT500KR to review they headed straight to the dyno to see how much power the supercharged V8 is putting out. What they found was somewhat surprising -- the KR produced 509 horsepower and 467.7 lb.-ft. torque to the wheels. Adjusting for an estimated driveline loss of 15 percent, the actual output at the flywheel is 589.82 hp and 550.24 lb-ft torque -- nearly 50 more horsepower and 40 more lb-ft than Ford is claiming.

http://www.autoblog.com/2008/07/16/g...s-the-king-of/

 

I peed a little.

 

Wholly potential

 

Makes me want or feel the need for one grrrrr

 

590hp is probably a bit optimisitc (see the LS3 fallacy) - drivelines dont absorb power in such a linear fashion, they absorb more or less a total power number and bounce around that depending on how stressed the components are.

Did Ford say that it was 540hp SAE verified? and if so to what standard? The vette with its transaxle and 430hp abosrbs about 10% of the power on the way to the wheels, I suspect that the GT500 and the KR are little different, not because an actual increase in effciency, but its more a less a case of the drivetrain only taking so much power to turn.

 

What's the MPG?

 

I wasn't a math major in college but I can't get thsoe numbers to match up. If the car is estimated to get 589hp at the flywheel then if it suffers a 15% drivetrain loss it should generate 500 at the wheels. So transversely if a car generates 509hp at the wheels then before a 15% loss its making 599 at the flywheel.

599-(599*.15)=509

509/.85=599

589-(589*.15)=500

So if they truly are using the 15% drivetrain loss and they did in fact produce 509 at the wheels, then by their math it should be 599hp at the flywheel.

Maybe they used another more accurate method.

Just my input thats all.

 

Interesting. Maybe in 5 years or so I'll be able to pick one up used for 5K

 

Awesome!

 

 

Ricer math. This "omg 15% driveline loss!" Doesn't hold water.

They used a Dyna-pack dyno. Driveline loss does not scale in a linear fasion. A 1000 HP GT500 engine wouldn't automatically measure 850 RWHP. There are a TON of variables. STD v SAE rating, type of dyno used ( Mustang, Dynapack, Dyno Dynamics, Dynojet, etc ). A C6 vette only shows a 9% driveline loss ( when stock ), actually verified. 509 on a Dyna-pack, I'd guess that KR would show 545HP SAE at the crank. Still, it's more than 540!

Dyna-Pack dynos connect straight to the hub with the wheels off, DynoJets are inertia type roller dynos. A Dynapack is one of the highest reading dynos there is. Stock GT500's can hit 485 RWHP off the showroom flow on those dynos, then 440 RWHP on a Dynojet, and then 395 RWHP on a Mustang Dyno. You wouldn't believe all the different numbers you'd get testing the SAME CAR on the different dynos.

The Dyna-pack will almost always result in numbers about 10-15% higher than what you'll see on the Dynojet.

Dyna-Pack
Removes the wheels and measure directly from the hub. Removing 40-52lb in unsprung and rotational weight is very significant. This dyno is also a load/brake dyno which means the operator can vary the load (brake) therefore influencing the numbers. Brake dynos are great for tuning purposes since you can vary load and tune for real world driving situations.

DynoJet-
This is an inertia dyno. You simply roll the drive wheels onto a set of ~2000lb drums. You put the car in a 1:1 gear and measure the time it takes to spin the drums in relation to engine rpm. From there, torque is read and HP is calculated.

Words of wisdom:

1) A dyno is a tuning tool...that's all. You use it to measure gains and losses from mods.
2) All dynos read a little differently
3) Only be concerned about what your car gets and not what Joe Blow's car did 5 states away. It's apples to oranges.
4) A 440rwhp GT500 run on a Dynojet will most likely run the same ET/MPH as a 485rwhp GT500 run on a Dyna-Pack.
5) You can make any dyno show power that's not really there (ie adjusting load, correction factors, atmospheric conditions).

Dyno's are for tuning, not determining crank horsepower by applying bogus math.

 

I agree.

 

Party pooper. Next you'll tell us the Bullitt only has 315 HP at the flywheel.

 

eci,

Thanks for the info. Nice to be informed.

Gary

 

thanks ECI I did not know there were that many different types of Dynos. I only knew the Mustang Dyno showed lower than others.

 

Man those are some are great numbers.