SCT Optional Parameters – FSWERKS

SCT Optional Parameters

When ordering an SCT flasher from FSWERKS, you first order your primary performance program. This is a single file that is programmed to your specifications. One restriction is that a single program flasher should not and will not be programmed for low octane or ultra-high octane race gas, as much of the performance gain comes from the timing associated with the use of 91, 93, and 94 octane fuel. Once you've placed an order for the SCT flasher and created its specifications to meet your needs, you should double check everything to make sure that it's accurate and what you want it to be.

Once that's done, you can choose to buy additional programs for only $50 each, up to 2 additional COMPLETE programs on X3 flashers and 9 additional COMPLETE programs on LiveWire TS flashers. Programs and options should not be confused for one another. A program is a COMPLETE tune file while an option is a specification or “tweak” within a program, such as raised idle or increased fuel pressure. You can have just one option or several options in a program and it’s still only $50 for the entire additional program. It’s NOT $50 for each option within a program. Once you get into the additional programs, you can add more octane options and a race gas option.


  • 100 octane option
  • Aggressive shifting at wide open throttle
  • Alternator disabled at wide-open throttle
  • Custom idle
  • Custom rev limit
  • Custom shift light setting at wide-open throttle
  • Drag Launch 
  • Early fan activation
  • EGR system disabled
  • Increased fuel pressure
  • Rear oxygen sensor disabled for race header

100 octane option
If you often take your car to the track and fill up there with 100 octane, then the base program (usually tuned for 91-94 octane) will not give you the timing advance you need. It will help a little bit, but if you want to run race fuel, you should advance the timing even further to take advantage of the higher octane. If you specify this option on one of your programs, NEVER use it unless you have completely emptied your tank and added race fuel, as it will cause detonation with even 94 octane gas. Please note that you may only select this option on multiple program flashers.

Aggressive shifting at wide open throttle
This option is for automatic transmissions only. The ECU controls the shift points of the transmission, and it just so happens that the FSWerks / SCT programming can alter these shift points. The car is always thinking about fuel economy, so the factory shift points are configured for gas mileage and nothing more. When you floor it, the FSWerks / SCT programming will shift in such a way to stay in the optimal power band, shifting when it's appropriate for performance, rather than fuel economy. In addition to changing the shift points, the programming also creates firmer, sportier shifts due to increased transmission fluid pressure. With this option shifting at part-throttle will remain at its factory setting.

Alternator disabled at wide-open throttle
This temporarily puts the car's entire electrical system in the hands of the car's battery. When the alternator is supplying power to the system, it becomes harder for the belt to turn it. By cutting off the load to the alternator, it becomes more like an idler pulley than an accessory. There's still some friction and momentum load from the bearings and armatures inside, but it's a noticeable difference versus the mechanical and magnetic load of the energized coils. To those who are concerned about their In-Car-Entertainment setup AND performance, you can simply place this as an option on a "strictly performance" program, and turn off all your ICE equipment to reduce the load on the battery.

Custom idle
Specify the idle RPM you desire in the notes field for each program where you choose this option. If you have aggressive cams, increasing the idle can help alleviate the shaking and bucking that the car does at idle. If you have an underdrive pulley, increasing the idle RPM can help keep the accessories running at their normal idle speed, which keeps headlights and instrument clusters from flickering occasionally. And if you have poly engine mounts installed this can reduce some of the vibration.

Custom rev limit
Specify the rev limit you want in the notes field for each program where you choose this option. Our default performance programs come with a 7200 RPM or 7600 RPM rev limit depending on model, but this can easily be raised or lowered. Be careful not to make this number too high, or you could be picking up pieces of your engine off the pavement. Also, keep in mind that without some serious modifications, you will actually lose performance and spend less time in the optimum power band by shifting too far up.

Custom shift light setting at wide-open throttle
This is an excellent option that turns the otherwise annoying “up arrow” on your instrument cluster into a useful shift light indicator. Normally it comes on to tell you when to shift for best fuel economy, however, we can command the light to come on at a specific engine RPM. For example, the factory setting on a Zetec Focus commands the light to come on at 5000 RPMs at wide open throttle as well as anywhere in between at part throttle, but we set it to illuminate only at your indicated RPM at wide open throttle.

Drag Launch 
The "Drag Launch" option provides a two-stage rev limiter for your car. You can customize the Launch RPM the same way you customize your Idle RPM and your Rev Limit RPM. The idea is to find the best RPM for you to launch at. If you don't know your ideal launch RPM, you might want to experiment at the local drag strip to find your ideal launch RPM before asking for this option. This can vary according to launch surface, temperature, and other environmental factors. When you're stopped, the launch RPM Limiter is activated. If your Launch RPM is set to 3,000 RPM, it will sit happily at 3,000 RPM when you put the accelerator to the floor. Once you are moving (after you dump the clutch) your Rev Limit RPM is activated. If you have a Duratec or SVT, you'll need to unplug one of your clutch switches in order for the program to work properly. The SPI and Zetec models can just use the program. The Drag Launch option cannot be added to your primary file. We will only create programs with the Drag Launch option on secondary files. Please remember that street racing is dangerous AND illegal. This option is for track use only.

Early fan activation
You can use this option to keep your engine temperatures cooler at idle and low speeds. It should be noted that cars that are running 1,000 RPMs or more at idle tend to run a bit hotter while sitting for long periods of time. The early fan activation will keep the car from over heating in such instances.

EGR system disabled
The Exhaust Gas Recirculation (EGR) system will pull a fraction of the exhaust gases from your exhaust manifold and re-introduce them to the engine. This process results in cleaner air being emitted from your exhaust system, but it also introduces air into the engine that is not only un-metered (is not measured or compensated for by the Mass Air Flow Sensor), but is also extremely hot and reduces the density of the air your engine is taking in. Those of you who are familiar with the "DPFE Stumble" know all-too-well what happens when too much EGR is applied by the engine. By default, the EGR System is disabled at WOT (wide open throttle) from the factory, but disabling the EGR System entirely, with an FSWerks / SCT flasher will make the car run smoother and better across the entire power band, regardless of throttle position.

Increased fuel pressure
Useful for those who are making a lot of horsepower with factory or larger fuel injectors, but run out of fuel, causing a lean air/fuel condition. The factory settings request about 40psi in most circumstances, but up to 75 psi can be used. Forced induction, nitrous, or extreme naturally aspirated tuning can benefit from this option by increasing the amount of fuel that can be used by the engine IF it is needed. If you don't have these things you will run too rich needlessly. And you will sacrifice power, have poor gas mileage, and possibly foul your spark plugs and send your catalytic to an early grave. Keep in mind that there is a limit to each injector size and pushing the limit to the extreme is not recommended. We do not recommend this option for most applications - Please call us for more details if needed.

Rear oxygen sensor disabled for race header or race downpipe
This option will disable the second O2 sensor on your exhaust system. On a stock Focus this sensor is responsible for monitoring the health of your catalytic converter. If you are using a hollowed-out cat, an off-road pipe, race header, or anything else that eliminates or nullifies the effects of the catalytic converter, then this option is for you. If you still have a healthy catalytic converter, but you plan on changing that soon, I also recommend this option, as it does not hurt the catalytic converter, nor does it hurt performance. If you use this option, you will not need a so-called "O2 Sensor Emulator", "MIL Eliminator" or anything of the sort. This option keeps the check engine light from coming on due to a problem with the second O2 Sensor.



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