For those of us who have been living with the late-model Mustang on a daily basis for a decade or more, the all-new '05 Mustang is truly exciting, and at the same time, a bit of a shock. Why a shock? Because we've become so comfortable with the existing car, so familiar with its details, that the all-new machine makes us realize just how much we need to learn about it.
So you can imagine our interest when Jim Bell, from Kenne Bell, wheeled out a brand new '05 GT the first week they went on sale. Like so many in the aftermarket, Jim was eager to get started on developing products-in his case screw-type superchargers-for the new car. And to do that, he didn't wait around for a promotional handout from Ford (almost none have been handed out anyway). He got his the old fashioned way, by exchanging paper with pictures of dead presidents on it.
Jim Bell's engineering background has given him a real curiosity about modifying cars. His is an analytical approach, where he straps the object of his attention to his Dynojet chassis dyno and systematically reduces variables-and disassembles a bunch of hardware-until he's sure about what's going on with the stock car, and what should be possible with modifications.
So, first thing Jim did with his new '05, aside from driving it half a day to get a feel for it, was to tie it to his dyno. The idea was to discover what makes the new Mustang rumble, lay a baseline as to its performance, and divine what sort of power could be developed from it.
It's important to remember that at this early point, no attempt was made to develop parts, at least not directly. The goal from this white-lab-coat session was to determine where easy horsepower might be had, "to see what Ford left us," as Jim put it, and occasionally, to define what might be the ultimate power potential in a certain system (the exhaust, for example).
To jump to conclusions, the new car doesn't promise tons of performance from dead-cheap bolt-ons. Ford has upped its Mustang game considerably, so the easy, low-hanging power fruit is now smaller and higher up the tree. But there is still fruit, and the Three-Valve cylinder head layout promises great power from more extensive modifications, namely forced induction.
Dyno TestingStep one was establishing a totally stock baseline run, and in the finest tradition of magazine testing, we even did that out of order. Kenne Bell had actually been dynoing the car the night before our arrival, while working with Superchips Custom Tuning on a software program for the Xcalibrator. In other words, Kenne Bell and SCT had been working on a tune for the new Power PC engine management computer and its Spanish Oak software. While toggling the Xcalibrator to the stock engine management program was super simple, the gas tank had a good load of 91-octane fuel in it. Ford says the Mustang runs on regular 87-octane, so that's what we wanted to see. We especially wanted to try regular gas once Ken Christley, Kenne Bell's electronics specialist, told us they had seen a gain, simply by switching to 91-octane fuel. But with so much 91-octane in the tank, it was decided to run several tests with it to burn some of it up, then drain the tank and run 87-octane to see what the difference was. We also requested a run with 104-octane unleaded race gas, that Kenne Bell keeps on hand, to determine if there would be any more power with even more octane.
As we started testing, we noted the car was instrumented to read out torque and horsepower, rpm, ambient air temperature, and the air/fuel ratio via a wideband oxygen sensor.