Justin Fivella
January 15, 2014

Dyno Numbers vs. Track Times

After the ECU Tuning, the plot only thickened when comparing the dyno numbers against the track gains—it didn’t add up. With Alan’s ’13 GT strapped down tight, we hit the dyno in box-stock form to the tune of 366 hp and 362 lb-ft at the tires.

After conducting the remote tuning rituals, Alan uploaded the AED tune into the GT and again hit the rollers. This time, the Coyote spun higher and pulled harder, with new marks of 378 hp and 375 lb-ft for peak-to-peak gains of 12 hp and 13 lb-ft at the wheels. Remember folks, this is a box-stock car, even down to the paper filter and all.

While the dyno gains weren’t anything to sneeze at, AED assured us the track results would prove far more impressive. So a trip to the infamous Sacramento Raceway in Sacramento, California, was in order. That’s right—on the same day of the dyno, we hit the strip for back-to-back results. Needless to say, we couldn’t believe our eyes.

The baseline numbers registered at 366 hp and 362 lb-ft at the tires, and the AED tune boosted the figures to 378 hp and 375 lb-ft for gains of 12 hp and 13 lb-ft on the stone-stock Coyote.

With AED hot-shoe and co-owner Drew Wallace behind the wheel, the box-stock GT pulled to the line and left without drama. On the big end, the boards read 12.80 at 110 mph—not too shabby. We made several additional runs within a tenth of each other to assure ourselves it was all she had.

A few minutes later, the AED tune was uploaded and it was time to make some tracks. The car didn’t leave any harder, but by the 60-foot mark, you could really see the Coyote come on the power as it ripped off 7,250-rpm shifts on a way to a best pass of 12.14 at 113 mph. We couldn’t believe our eyes. How could a tune that only added 12 hp and 13 lb-ft knock off 0.6 and add 3 mph in the quarter? Thankfully Perry was there with the answer.

“The dyno gains aren’t that important. It’s the fact that these cars have a dyno mode that only unlocks full power when the front wheels aren’t spinning, but get them on the road and they have all kinds of nannies—like torque management and piston protection—that kills serious power,” Shaun explained. In other words, your Coyote might make a solid dyno number, but that doesn’t mean it’s actually making that much on the street or the track.

Such concessions to civility (and warranty claims) are to be expected from a factory vehicle, and is more proof that we’ve truly entered a new era of Mustang tuning. Just a few years ago, dyno gains were directly correlated to track gains, but not anymore. Who would have thought the Coyotes were so technology rich they’d have the ability to dial back their own power?

Perhaps we should thank the Ford engineers—after all, what makes the new Coyotes so powerful they can self-regulate also gives experienced tuners the ability to gain massive amounts of power. Welcome to the Coyote era, where the capabilities are nearly endless. It’s good to be a Ford fan.

A trip to Sacramento Raceway proved that dyno numbers aren’t everything, since the electronic nannies in the stock tune were hampering the track results. Our baseline times were 12.80 at 110 mph, but fell to a best of 12.14 at 113 mph for gains of 0.6 and 3 mph with just a tune—now those are impressive results.

Remote Tuning 101

Here’s the checklist Shaun Perry of AED sends to all Coyote owners before conducting a remote tune:

  • Using the latest version of SCT Live Link Gen2, log the following on a fully warmed engine: rpm, spark, spark V2, MAF lb/min, MAF frequency, load as a fraction, actual throttle angle, intake air temp, long-term fuel trims, short-term fuel trims, Lambse B1/B2, and measured air/fuel.

  • I want two logs:
  1. 1. Part throttle in Third, very slow acceleration from 1,100 to 5,000 rpm, followed immediately by a few minutes of idle.
  2. 2. WOT from 2,000 rpm to redline (preferably on a chassis dyno) in Fifth gear for manuals and Fourth gear for automatics when on the dyno. If at the track, use Third gear.

  • Doing the idle log after a part-throttle pull ensures the O2 sensors are up to proper operating temps for accurate data at idle. This is especially important for long-tube applications.
  • If the logs look normal, we can proceed with tuning once you send the following: ECU calibration code, X-Cal serial number, rearend gear ratio, and a full list of modifications.