Without a doubt, the '05 Mustang is slated to become a classic in terms of both styling and performance. Yeah, we've heard it all before, but this car never ceases to garner attention, whether cruising down Main Street or proudly parked curbside. The ads featuring the digital ghost of Steve McQueen aptly summed it up, "If you build it, they will come." And they have--right into the dealership.
For some of us who are old school in terms of building horsepower, hopping up a late-model car with all of its gizmos and New-Age controls can be a daunting task. Truth be told, the reason that all these cars get such good mileage while still being capable of blistering the quarter-mile is due to computer science. Sensors and computer code allow the car to automatically react to different circumstances and conditions, reading factors like air speed through the intake inlet above the throttle body and exhaust heat, then instantly changing settings for camshaft advance, ignition timing, and other components based on that data. Unlike in the old days, if you make a big hardware change, the car may not run as well or go as fast as it did stock. You need to reconfigure the computer to adjust to the new environmental conditions surrounding the engine's computer-driven responses.
However, because of this computer science, it is also now possible to build fresh horsepower without ever lifting a wrench. In the past, an aftermarket chip was a big part of this; just put a new chip in place of the factory unit. Nevertheless, the new Mustang does not have provisions for a removable chip; changes need to be made to the factory computer software by reflashing (reprogramming) a new tune into the stock computer. This is where DiabloSport's latest version of the Predator comes in.
Based in Boca Raton, Florida, DiabloSport has been a leading player in the OEM computer reprogramming business for several years, building products like the custom Delta Chip burner, the diesel-based Power Puck, and the DiabloSport Predator tool seen in our story. Since 1992, these guys have reworked OEM electronic products for many automotive applications. DiabloSport was founded to service the American performance industry in 2000. For the '05 Mustang, the company sells a pre-programmed "flash tuner" unit (PN U7140) that allows for both quick tuneability and ease of installation; the Predator uses your car's battery power, is plugged directly into the OBD-II port under the dash, and can install a hotter tune in less than 10 minutes. It also adjusts the transmission computer, as well.
By installing this program into your new Mustang rather then swapping in fresh hardware, the DiabloSport Predator lets you have your cake and eat it. The performance code is not permanent, and with the click-through menus in the DiabloSport Predator's LCD screen, it is a simple task to reinstall the factory program if the car needs to be base-lined or go in for service.
How Does It Work?
The code that DiabloSport's engineers have written adjusts various engine management parameters to increase performance while keeping fuel economy in mind. The DiabloSport Predator will first retrieve a copy of the stock vehicle computer program from your car and use data from it to lock itself to that specific computer. This is required because the DiabloSport Predator performance tunes you get with the tool are written and saved as difference files; these files use the stock computer program you just downloaded, apply performance-related overwrites to it, and then re-flashes that adjusted program back into the vehicle computer.
For this reason, your Diablosport Predator can only be used in one car unless you restore the copy of the stock program back to the car's computer. You can then use it in another vehicle with a fresh stock computer download. We will note here that while many of these adjustments are within the realm of most emissions standards, they are not approved by CARB for highway use in sunny California.
The OBDII port is located under the dash and is easily accessible; this is where the dealership service department also plugs in its diagnostic equipment. The DiabloSport Predator is plugged in and will begin by giving basic info and a disclaimer (mainly because this product will disable the rev-limiter in the 4.6-mod motor--programmed at the factory for an anemic 5,650 rpm). After entering the initial data, including a VIN code so it is for your car alone, it will ask you which tune you want to install: the 87-octane performance tune, the 91-octane performance tune, the 93-octane performance, or the stock tune you started with. There is even room for up to five custom tunes if the car has been uniquely or extensively modified; these special tunes can be custom-made by any of the 170 ChipMaster Revolution dealers nationwide.
As you click through each question, the LCD screen will track the progress of the unit. You will know the factory tune is being downloaded into the DiabloSport Predator when it asks you if you want to modify the tune or install it. For this test we simply modified for the 93-octane tune and then installed it with no changes. Using a bar graph similar to what you may see when doing updates on your home computer, the LCD showed us that the tool was creating the new tune, and then showed us it was being installed.
For our test, we used the load-bearing Superflow dyno at the DiabloSport research and engineering facility. The only modifications to the three-week-old test car were a fiberglass hood, better rubber, and a cat-back exhaust; it was stock under the hood. The numbers above are corrected to represent SAE Dynojet numbers and all of the runs were made at the same exact temperatures.
But Wait, There's More...
You've got the new tune in and you're enjoying that feel in the seat of your pants, but you would like to do some more tweaking on the package. Unlike other flash tuners, the DiabloSport Predator does not simply stop at reprogramming the factory computer, it can also be used to make incremental adjustments.Plug your DiabloSport Predator back into the OBDII port, click through the data questions, and you can begin to modify it by advancing the timing, adding more fuel to the injectors, and other changes. Using the software, you are allowed to adjust the already scienced-out DiabloSport parameters by as much as 10 percent. Once you've made your changes, click through to install the changes and within five minutes you have got your new adjustments in the car, and you never even opened the hood.
Of course, being hot rodders, a little too much may be a problem, especially if making several changes at once. In case you get really lost, plug in the DiabloSport Predator and reinstall the stock tune once again to bring everything back to zero and start over from scratch. That is the true beauty of this unit; you have very little chance of making any change to the car's computer permanent.
Let's go one step further. Let's say you want to add a cold-air kit from Steeda. This is going to make readings through the MAF (Mass Airflow) sensor much different from stock, which can throw the stock computer program into chaos. DiabloSport has worked closely with Steeda and other aftermarket suppliers to have tunes ready for these changes . A few of the most common parts changes come pre-installed in the DiabloSport Predator; simply click through and add the parts to the tune you are installing.
Others are being added at the company's website www.diablosport.com on a continual basis; any of these can be downloaded free of charge from the Web site into your Predator using a standard serial cable, then installed into your car. It is as easy as it sounds. As mentioned earlier, the company's 170 ChipMaster Revolution dealers can also create custom programs if you have made unique adjustments.
Removing the Hydrocarbon Trap
298.4 hp/ 312.4 lb-ft
One other thing we did between pulls was remove the air-restricting hydro-carbon trap in the intake pipe (see sidebar "A Quick Fix"), which previous dyno pulls had shown to be worth several horspower in itself. With this done, the dyno numbers got better. By 4,800 rpm, the engine had hit 280.5 horses, maxed out at 298.4 at 5,900, and stayed above 290 horses from 5,100 rpm through 6,400 rpm. Torque was a thumping 312.7 at 4,500. While the maximum number increase was not huge, the increase in the overall powerband was very impressive without changing anything but pulling the filter.
Installing the Steeda Goods
321.2 hp/329 lb-ft
While our test car was left mostly stock, we looked at the data from a recent test pull done on an '05 Mustang that had received the cold-air kit, the cat-back exhaust, the charge-motion control valve controller, and the underdrive pulleys, all from Steeda (954-960-0774). This is where the DiabloSport Predator really turns on, as it adapts the computer to multiple parts changes. Once installed, the torque was already at 281.2 lb-ft at a starting number of 2,700 rpm, peaked at 329.0 at 4,500, and stayed above 270 through 6,200 rpm. The hp number hit 261.1 at 4,300, climbed quickly to 300 by 4,900, and peaked at 321.2 at 6,200, falling down by only 13 hp to 308 by a max rpm of 6,700. Note that this equipment did move the max hp and torque numbers much higher in the powerband.
The truth is, the Mustang comes fairly hot in stock trim. To see increases of 50 horses or more will require a blower or nitrous; there are no other quick horsepower fixes. The DiabloSport Predator can also adapt many of the changes and are yours by simply downloading the available aftermarket tunes form the Web site.
Finally, what if you cannot find your part application, or run into something you didn't expect? DiabloSport maintains a technical support crew who are capable of answering most questions regarding all of its products, and the R&D staff spends a lot of time making dyno pulls on various combinations, ranging from bone stockers to high-horsepower supercharged applications putting out 600-plus ponies at the rear tires. Because they know just like you do, it is always better to be the Predator than the prey.
A Quick Fix
One thing that the Ford factory added to the intake tube going to the throttle body was this restrictive hydro-carbon filter made of ceramic-coated metal to aid in the emissions process. It does very little good and creates a huge airflow restriction on the '05 Mustang. The solution is to pull that little bugger out of there. From hard experience, this will take at least one buddy to either hold the intake tube, or, if he is stronger than you are, to grip two pair of needle nose pliers and yank hard. On the dyno, this change alone is worth several ponies at the back tires. A better recommendation: add the Steeda cold-air kit and a DiabloSport tune at the same time, leaving the stock stuff intact in a corner of the garage in case you need to reinstall it
New Car Warranty
Does the DiabloSport Predator affect your warranty? Like any aftermarket change you may make, the dealership you bought the car from may argue that you have voided your warranty if you install an aftermarket computer program. With the DiabloSport Predator, you can reinstall the factory tune with no problem, but the car's computer also keeps a record of when it was accessed. Some customers have gotten around this visibility by taking the car into the dealership for a quick diagnostic look on the day the tune was installed while it was still stock. Truth be told, the 10 percent adjustable options built into the DiabloSport Predator will likely not be enough to cause problems as long as you are using high-test fuel to prevent detonation.
