Dale Amy
January 1, 2005

Horse Sense:
Another tuning tip from SCT: Beware of race-style blower bypass valves immediately downstream of a mass air meter. The big blast of air belching through the bypass can apparently cause reversion in the meter, screwing up its accuracy.

In the past, the raging flood of aftermarket Mustang speed goodies sometimes drowned out our ability to tune the resultant combinations, with the consequence often being less-than-optimal driveability, or in worst-case scenarios, premature short-block self-destruction. It used to be that tuners faced with unusual combinations or anything at all north of, say, 450 rear-wheel horsepower often turned to such drastic steps as tossing out the street-friendly mass air meter and starting all over with some form of aftermarket speed-density system. Or, they settled for creating a relatively safe wide-open-throttle tune, while sacrificing some aspects of driveability and efficiency that are so important on a street-driven vehicle. We're happy to report those days may soon be over, thanks to the rapidly advancing science of electronic tuning. A relatively new firm, Superchips Custom Tuning, is one of the generals leading the charge in this technological revolution.

Obviously, electronic tuning is nothing new-it has been evolving ever since Ford first slapped an EEC processor onboard to precisely oversee fuel and timing strategies in response to ever-changing driving conditions. But lately we're seeing quantum advances in the areas of tuning software and hardware sophistication, user-friendliness, and the resulting ability to civilize even the wildest of powertrain combinations.

This is a good thing, because even outrageous power gets old fairly quickly without good start, idle, and part-throttle manners.

The name "Superchips" should be familiar to most readers, as the company is best known for its respected line of off-the-shelf performance chips for stock or near-stock applications. But let's be perfectly clear that Superchips Custom Tuning is a wholly separate corporate enterprise that is only 25 percent owned by Superchips. As its name suggests, SCT's specialty is on the custom tuning side, working through an ever-expanding network of dealer/tuners, such as Paul's High Performance, where we researched this article. To be more specific, SCT's goal is to engineer and put the necessary hardware and software in the hands of skilled tuners so those experts can quickly and efficiently sort out the hairiest of combinations for maximum performance, driveability, and durability.

The Talent
SCT's ownership and staff is populated with tuners, calibrators, and engineers, some of whom have had previous careers with Ford or other auto manu-facturers. They are fluently conversant with the ever-increasing complexity of engine/powertrain control modules, as well as the programming logic applied to them, and they know how to calibrate not only for power, but also for genteel demeanor and peak efficiency.

For the past several months, some SCT calibrators have been out around the country, working closely with in-the-field tuners such as Paul Svinicki on both popular and unusual combinations in order to establish a solid library of "baseline" tuning files. SCT President Chris Johnson tells us this library already contains no fewer than 37,000 files for Ford applications alone, meaning no matter what combination you're putting together, odds are SCT already has a baseline file for it. Upon arrival at your dyno facility, the tuner can load that baseline into your processor and immediately be fairly close to a final tune, rather than having to take the time to establish a calibration from scratch.

Obviously, no two cars are exactly alike-even if they wear the same hardware-so arriving at the best and safest tune still involves strapping the car on the dyno, plugging in a wide-band oxygen sensor, and likely some form of datalogger. But the point is, having a close baseline is more efficient for the tuner and therefore cheaper for you. It's also easier on your car, as the number of dyno pulls is likely to be substantially reduced.

The Software
SCT's Windows-based tuning software-called SCT Advantage-also eases the tuner's job, as it is presented in plain English and has built-in explanation info on just about every parameter with which the tuner can fiddle. And-boy-has a lot of the factory's hexa-decimal programming code now been unscrambled. The number of factory calibration parameters decoded by the current generation of tuning software is one of the greatest advances in getting even quasi-insane combinations to run with OEM-like driveability. Compared to what was available to tuners even a couple years ago, this new stuff is, in sophistication, like a doctoral thesis versus a high-school term paper. Demystifying the EEC processor's OEM programming code is even more important these days, when that computer may control not just the engine but also an automatic transmission if so equipped, meaning an auto's line pressures and overall shift characteristics can now be included in the tune-up process.

The Hardware
SCT teams its user-friendly software with some leading-edge hardware that is equally agreeable to work with, such as its CHIPper chip burner, said to be the only one on the market that is USB compatible (rather than using the sometimes troublesome serial or parallel ports), and will program chips as much as eight times faster than anything else on the market, says SCT. The CHIPper is also powered by your laptop, via that same USB cable, so with a fully charged laptop battery, it becomes a truly portable chip burning tool.

Time marches on, and the days of chip-tuning a brand-new Mustang are about over, as the old EEC series bows out in favor of the much more sophisticated Black Oak processor with the advent of the '05 Mustang. This new processor must be "flashed" via its OBD-II port-the way Ford dealers have recalibrated for some time now-as there will be no place (such as the EEC's J3 port) to stick a chip on them. Until recently, the equipment necessary to flash-tune has been prohibitively expensive, not to mention hard to come by-especially to consumers.

One of the problems in owning a Mustang that needs to be flashed is that, unlike those that can take SCT's four-bank chips-which are capable of being programmed with up to four switchable custom tunes, an off mode that defaults to your stock calibration, as well as an antitheft mode-there's no way to flash more than one program at a time into the EEC. So if, for instance, you have your blown ride tuned right on the edge for 93-octane fuel, and you find yourself in California where they serve only that 91-octane mineral water, you'll have to go easy to avoid detonation. Unless, that is, you acquire one of SCT's Extreme Flash Tuners. Think of this as sort of a handheld switch-chip, in that it can hold up to three custom programs that you can flash through the OBD-II port as desired. Ideally, we suppose, you go to your local SCT tuner, have the three custom tunes worked out on the dyno (say one each for regular, premium, and race fuel), and then buy the Extreme Flash Tuner with those spare tunes loaded. It also offers a number of user-adjustable parameters, including timing and fuel tables, gear-ratio calibration (for '99-and-newer cars), and it acts as an OBD-II code reader and eraser.

Last, but by no means least, SCT has added a pair of precisely calibrated, high-flow mass air meters to its tuner-available hardware list. Without doubt, a mass air meter's transfer function is one the most important keys to getting a vehicle to run right at any modification level and in any weather condition. In short, the transfer function is the meter's means of telling the processor how much air is being ingested at any time, by precisely equating a given mass of incoming air to a given meter output voltage. Since the car's processor uses this air-mass data to calculate engine load-or volumetric efficiency-and determine the required fuel and spark response, the accuracy of the meter's transfer function couldn't be any more critical. So, to speed tuning high-horsepower applications, SCT decided to commission meters manufactured and calibrated by Hitachi (which, to our knowledge, still makes all of Ford's factory meters) in two known, repeatable calibrations-one for up to 2,400 kilograms per hour of airflow and the second for up to 2,700 kg/hr. Those numbers indicate the airflow at which the meter is "pegged," or registers the maximum of just under 5 volts readable by EEC processors. The 2,400 kg/hr meter is targeted at cars in the 450-680 rwhp range, while the 2,700 kg/hr meter is intended for those producing between 650 and 800 ponies at the tires. Both meters use the common, 90mm Lightning plastic housing with revised cali-brations (for comparison, SCT tells us a stock Lightning meter calibration pegs at less than 1,600 kg/hr).

The idea is that the tuner need only tell the Advantage software which of the two meters he's using and how big the subject vehicle's injectors are. The car should start right up, idle like a limo, and need only a couple tweaks of the transfer function to finish the tune. The software eliminates the need to calibrate the meter to a single, specific, injector size. During our visit to Paul's High Performance, we witnessed a couple demonstrations of this theory at work (see sidebar below) and can attest to its effectiveness on those vehicles.

A Practical Application of Theory
SCT received its first shipment of mass air meters just in time for our meeting at Paul's High Performance. There were a couple "problem cases" at PHP that had resisted previous attempts of tuning for startup and driveability. One of those was Karl Roekle's blown and aftercooled '97 Cobra that you may remember from the King of the Street shootout in our May '04 issue. Karl had made some changes during the winter that took much of the pleasure out of the car's driveability, to the point where he wasn't even driving it. Specifically, he had ported the Four-Valve heads, dropped compression a bit with dished pistons, and swapped from 55-lb/hr injectors and a 92mm mass-air to Siemens 60-lb/hr squirters and a 95mm mass air. Despite valiant efforts, the car had truly ugly startup, idle, and cruise-throttle manners-perhaps about what you'd expect of a 650hp modular.

But, after swapping on the new SCT BA ("Big Air") 2400 meter, loading its transfer function into the EEC via the Advantage software-and making no other changes-it started and idled like a stock Cobra. On the dyno, the transfer function needed only slight tweaking to lock in the desired A/F ratio up top under boost. After only about four pulls, everything looked great, so Karl headed to the street with yours truly riding shotgun. The car exhibited its usual tire-frying exuberance, but otherwise it felt factory civilized. Karl even tried some steady-state throttle at 1,200 rpm in Sixth gear-a maneuver normally guaranteed to bring on all manner of bronco-like bucking-to no ill effect. In summary, as the always-quotable Mr. Roekle exclaimed, "It ain't never run that good!"

Back at the shop, Chris Johnson and Paul Svinicki went to work on a couple more tough cases, including a blown modular GT ragtop and a V-10 Super Duty with a Whipplecharger plumbed to what looked like a homemade intercooler setup. Both were tuned in short order, helped by the new meters.

While watching, we learned a useful SCT tuning tidbit. On blown vehicles, it's important to put an Air Charge Temp sensor in the inlet tract as close as possible to the throttle body, since SCT's software includes a table to pull timing as the air-charge temp rises-as on the factory-blown Cobras and the Ford GT. It's one more way this stuff can help keep your engine together.