When it comes to improving the performance of your Duramax, Cummins, or Powerstroke, diesel tuning is always a great place to start. It offers some of the best value when it comes to price and performance and can make your truck feel like a whole new vehicle. However, when it comes to choosing which type of tuning to go with there seem to be two distinct yet similar options out there, Box Tuners and Custom Tuning. This article will help you decide which option is best for you.
How They Work
Box tuners manipulate the data stream of different engine sensors to provoke a desired engine response. In most cases, this consists of manipulating map sensor values in order to trick the ECM into adding more fuel into the combustion chamber. The idea behind this is that most diesel and even gas engines run on the leaner side of air and fuel mixtures. By increasing the amount of fuel in the combustion chamber more air is able to be burned, which in turn creates more power.
The Good
Box tuners are a quick and easy method of making more power out of your diesel engine. Due to their more affordable price tag, they are a popular option among new diesel enthusiasts. Box tuners have the ability to increase the power of a stock engine with almost no prior knowledge required on the part of the user. Since box tuners do not change any engine programming and simply manipulate the signals going to and coming from the ECM they leave relatively no trace when removed from the vehicle. This makes them a solid option for those who are looking to retain their factory warranty.
The Bad
Manipulating signals coming from important engine sensors can be a dangerous game to play. Especially when your engine has no idea what its actual operating values are. Your ECM relies on readings from these sensors to keep your engine operating safely and at peak efficiency. A common complaint from box-tuning customers revolves around increased smoke output. Smoke is the result of unburnt fuel after combustion. Since box tuners primarily work by increasing the amount of fuel being added to the combustion chamber they are extremely prone to this issue. This excess un-burnt fuel being sent out the tailpipe not only wastes fuel, lowering your MPG, but can also end up clogging your DPF and EGR system with soot.
While box tuners often boast impressive performance gains, sustained performance is not their strong suit. Often performance starts to slip or even fall below stock numbers after just a few pulls on the dyno. You'll definitely want to steer clear of these if you're hoping to improve your sustained towing performance. And just like any other electronic device, these tuners can malfunction out of nowhere, which can cause poor performance or even engine damage.
Since these devices do not offer any transmission tuning to compensate for the change in power and torque bands. Shift quality, after installation of a box tuner, often suffers. Another major downside to box tuners is the lack of ability to run other modifications in conjunction with them. Since box tuners are completely designed around a stock engine calibration they aren't designed to compensate for increased air flow that other upgrades may provide. Running upgrades like aftermarket intakes or turbochargers with a box tuner installed can actually result in decreased engine performance. Not to mention it also has the possibility of damaging your engine and emissions system components.
How It Works
Custom tuning is a process in which your vehicles stock operating files are extracted and precisely modified to maximize your engines performance. Dozens of engine parameters are adjusted to provide the most complete engine tuning possible. Things like injector timing, fuel trim, turbo vane position, and much more are all delicately balanced. Tuning is also fully customized to your engines specific configuration. Meaning if you have aftermarket upgrades on your vehicle they can be taken into account and tuned for specifically. Factory safety limiters are still kept in place to ensure your engine stays protected even with the additional power from tuning. Custom tuning isn't just limited to engine tuning either. It also allows tuners to modify the transmission control module (TCM). Everything from shift points, shift timing, and even clutch holding capacity can be adjusted to better utilize the improved power band from ECM tuning.
The Good
The biggest advantage custom tuning has to offer is the over all power it can provide. Due to the numerous adjustments that can be made custom tuning generally provides more power than box tuners are able to. Most customers who switch from box tuners to custom tuning report experiencing a night and day difference between the two. Custom tuning not only provides you with more peak power but also more power across the entire operating range of your engine. Unlike box tuners that are simply designed to achieve a peak power number. Custom tuning is designed to provide sustained peak performance. These aspects make custom tuning a great choice for those looking to improve their towing performance.
If you have or plan on installing other modifications on your engine you'll defiantly want to go with a custom tune. Only custom tuning can be designed to take into account aftermarket upgrades which will maximize the potential power gains from them. Custom tuning can also be updated in the event that you ever add another modification, or change tire sizes.
The amount of adjustments that can be made with custom tuning allows for much cleaner and more efficient combustion. This improved efficiency results in more power, less unburnt fuel exiting the tail pipe and less soot production than even a stock tune produces. You will benefit by experiencing less frequent re-gens and better fuel efficiency. Another major benefit of custom tuning is the ability to tune the ECM as well as the TCM. TCM tuning can further enhance the power from ECM tuning by optimizing shift points and delay between shifts. This allows your truck to get more usable power to your wheels. The combination of ECM and TCM tuning drastically improve overall your over all sense of power and drivability which is important for those who use their truck on a daily basis.
The Bad
Custom tuning can often be a confusing space to navigate for beginners. With multiple flash tool options, power levels, and companies too choose from the choices can often seem intimidating and overwhelming. As a general rule of thumb we recommend finding a custom tuning company with at least 10 years of experience under their belt. This means they have a solid understanding of how modern diesels operate and most likely have an experienced staff that can support the product. When it comes to choosing a flash tool we have created a helpful chart which outlines the features of each to help you narrow down which option would be best for you. Just as a reminder, generally the more features a flash tool offers the more expensive it will be.
Custom tuning can require some computer know-how to be able to install it on your truck. In most cases your tuner will have a step by step guide on how the tuning process works and what you will need to do in order to get it installed. Some custom tuning companies even offer the ability to bench flash your stock ECM which only requires the mechanical know how of removing the ECM from the vehicle.
Custom tuning, while not likely, does have the potential to void your vehicles factory warranty. From our experience this is a pretty uncommon occurrence. However, it does happen. Some companies offer the option of an ECM swap which in theory should allow you to hide all traces of the vehicle ever having been tuned. If your warranty is a concern to you it's always a good idea to consult with the tuner you are thinking about going with before making the purchase.
The only other down side we see with custom tuning is how much power it can make. Which at first may sound like a good thing. But when it comes down to it, custom tuning does leave users with enough power to damage their vehicle if they are irresponsible. Sustained towing in the max effort tune without proper gauges will most definitely damage your engine. If you are worried that you or someone else who drives the truck may cause damage driving the truck irresponsibly your tuner may have options such as key lock switches or dedicated towing tunes that can help to address this issue.
If you're limited on funds and just want to get a taste of what diesel tuning is capable of, sure, a box tuner is a perfectly fine way to see how much more power your engine is capable of producing with no other upgrades. Be careful though, because it might end up costing you later down the line. However, if you have just a bit more room in your budget Custom Tuning is certainly worth the cost. Over all custom tuning will always be the better option because it offers total and precise customizability of your engines calibration, providing more power than box tuners do, while also remaining safe for your engine and emissions system. It can be a night a day difference even coming from an already box tuned truck. Plus custom tuning is a much more long term solution which doesn't require a device to remain plugged in to your OBDII port and comes with tunes that are designed to provide sustained performance. While a box tuner offers a reasonable bump in performance for a reasonable price they are simply not worth the potential risk they pose to your engine and emissions system.
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