05 10 Mustang GT Performance Tune


Using the latest software from SCT and their new Xcalibrator4 hand held flasher we’ve developed a new performance tune for the 2005 Mustang with the new 3-valve 4.6L and 5-Speed manual transmission that unlocks performance and throttle response.

Our new tune has corrected the number one complaint with the new ‘05 Mustang – “laggy” throttle response from the fly-by-wire throttle control. The new 3-valve mustangs no longer have a throttle cable going directly from the gas pedal to the throttle body. They now have a ?throttle-by-wire? system to open the throttle based on your input at the traditional gas pedal. Ford’s new throttle-by-wire on the Mustangs has a few intentional shortcomings. It is intentionally programmed stock to NOT snap the blade open as quick or at the same rate the driver moves the pedal. Additionally the stock program begins to shut the throttle blade as you approach the stock rev limiter, this ?eases? the engine into the rev limiter as opposed to ?slamming? into it. This causes an awkward, incorrect power-shift, negatively affecting the ability to drive the car aggressively to achieve maximum acceleration and ET by power shifting.

Our test car started out with 87 octane in the tank as recommended by Ford to use in the manual. The base line pulls from the car averaged 265 RWHP and 276 ft lbs of Torque. After switching to 93 octane and a few other tweaks in the computer and removing the latest in emissions devices that is in the intake track of all the new Mustangs, we found 20 more RWHP.

The new Mustang has a device in the intake track that’s what we call a “Pre-Catalytic Converter”. This device catches vapors that are emitted from the engine after it’s been running and is then shut off. Just after a hot engine has been turned off they can emit unburned fuel from the intake track. This device absorbs those vapors and stores them until the engine is started again, then lets the stored vapors get sucked back into the engine to be burned off. Removing this alone was worth about 4-5 RWHP!

We also found the new Mustang’s Air/Fuel ratio to be very rich at Wide-Open-Throttle (WOT) after the engine got above 4500 RPMs. We observed an 11.8:1 factory ratio with our very accurate “Non-tail-pipe” style O2 sensor. We adjusted it to keep the A/F ratio at WOT at a more optimal setting of 13:1.

After switching to 93 octane premium fuel we got more aggressive with the timing while on the dyno. This improved low and mid range power with some gains in the high revs also.

The new 3-valve Mustangs also have computer-controlled cam timing. By modifying this we found some additional high rpm power and extended the power and torque curve as well.

By removing the “Pre-Cat”, switching to “premium fuel”, and implementing a well-thought-out computer tune/flash we gained 20 RWHP and substantially better throttle response. The new flash can be felt immediately, even under light to moderate throttle conditions.

This is an excellent initial performance tune for anyone looking for noticeable gains.

In the future we will be testing long tube headers and other exhaust components on the ‘05 GTs and many other performance bolt-ons as they become available.

Xcalibrator4 Flash Tuner

The Xcalibrator4 Flash Tuner will reprogram your Ford ECM with the custom performance tune that we load onto it. Before installing the new tune it will download and save your factory calibrations so that the vehicle can easily be returned to stock.

  1. Can hold up to 10 Custom Calibrations

  2. Retains Factory Calibration for easy restoration back to the stock calibration

  3. Easy installation. No tools necessary

  4. Easy to use push button & LED interface

  5. Quickly Flashes PCM via OBD-II diagnostic port

2005-10 Mustang Alternative Auto Performance Tune and SCT Xcalibrator4

Please call the shop for more info and ordering.


’05-10 Mustang gt performance tune

Delivers a proven 20 rwhp gain!

Performance Gains Delivered!
The dyno graph shows how we’ve corrected an overly rich factory tune at Wide Open Throttle and found big increases in both HP and torque, plus extended the available HP and torque higher in the rev range.

Chips, Flash Devices and Custom Tuning
It’s What’s Inside that Counts

At Alternative Auto we develop custom performance tunes that are based on our vast experience and knowledge of how to make impressive amounts of power while retaining stock-like drivability. It is our experience, philosophies and methods that elevate us to a level much higher than other tuners.

There are many other companies that sell calibrator or flash devices like the Xcalibrator4 and custom burned chips. We want to make it clear that when it comes to these devices, it’s important to remember “It’s What’s Inside that Counts”. Even though we (tuners) may all be using the same type of software and even the same type of flashing devices with access to the same parameters, it’s how well thought out the tune and calibration is on the inside that counts. Even though some competitors offer similar devices, sometimes at a lower cost, they can not equal our experience and knowledge of how to make Ford vehicles perform and maintain stock-like drivability and reliability.

Many mail order tuners in the country who sell tunes only offer a very limited program that simply raises or remove rev limiters, speed limiters and adds a global degree or two of timing. We take the time to sort out much more then the basics. Especially on modern Fords with the automatic electronically controlled transmissions with lock-up torque converters. We unlock a substantial amount of improved drivability on today’s Automatic Fords because of how we reconfigure torque converter lock-up and torque reduction during up-shift. We provide a complete tune with many additional changes such as turning electric fans on earlier, recalibrating speedos for gear and tire changes, turn off “Check-Engine” lights from exhaust and other performance enhancing changes, make the fly-by-wire throttle respond better, etc…

So be educated, “Its what’s inside” that really counts these days when it comes to custom tunes installed in hand held tuner devices or custom chips and no one does it better than Alternative Auto Performance.