We have previously featured two other stories about the new Ford Shelby GT350 Mustang on the dyno and, once again, we have a very different set of numbers. Back in October, Motor Trend put the GT350 and GT350R on the dyno with results of 467 rear wheel horsepower for the “base” car and 471 rear wheel horsepower for the GT350R.
Earlier this month, we looked at some tuning results on a GT350 with and without a new JLT cold air intake, and that piece also include stock baseline numbers. During that baseline test, the GT350 Mustang “only” made 451 rear wheel horsepower while the cold air intake and a tune lifted the output of that Shelby to 484 rear wheel horsepower.
So, Motor Trend got 467 rear wheel horsepower for the Shelby GT350 Mustang while a private owner at an independent shop got 451 rear wheel horsepower. Those are two very different numbers and there are a variety of factors which can lead to these differing figures. Air quality, air temperature and dyno calibration can all lead to different numbers – and that helps to explain that numbers seen by the folks at Hennessey.
GT350 Mustang on the Hennessey Dyno
Hennessey Performance has big plans for the Ford Shelby GT350 Mustang, including a supercharger setup that will lift output over 800 horsepower. Before building the new Shelby Mustang, Hennessey wanted to get baseline numbers on a stock GT350 and the results are the best we have seen. In the video below, the GT350 Mustang lays down 482.46 horsepower and 407.02lb-ft of torque at the rear wheels.
I imagine that this particular dyno run took place in ideal conditions, including cool Texas winter air with a power-friendly elevation level at the Hennessey facility. Even with those superior conditions, these numbers are shockingly high, as 482 rear wheel horsepower leads to a drivetrain loss of just 44 horsepower from the official rating of 526. That is a drivetrain loss figure of just 8% - which is unreasonably low. This means that the flat plane V8 is heavily underrated – and by a fair amount more than the other cars we have seen tested – or this dyno is a bit friendlier than the others.
We should keep in mind that the folks at Hennessey recently saw shockingly high power figures from a stock Camaro SS, so maybe the HPE dyno is reading a little high right now. On the other hand, maybe the other dyno shops were too conservative, but in any case, the new Ford Shelby GT350 Mustang sounds incredible on the dyno as the 5.2L flat plane V8 screams into the high RPM range, so you want to make sure that you can watch these videos with your speakers turned up.
After watching the dyno video, check out the second video, which offers and in-car look at the gauges as the GT350 Mustang climbs up to 170 miles per hour.