More Power from Stock Pickup Trucks with Aftermarket Tuners
Unleashing the Horsepower and Torque from Stock Pickup Trucks with Aftermarket Tuners
The Engine Control Unit (ECU) that manages the electrical system and subsystems on a pickup truck is programmed at the factory to comply with certain emissions and fuel octane requirements resulting in less than peak horsepower and torque.
However, with the use of an aftermarket tuner, adjustments to the vehicle’s settings can optimize engine output even without adding any physical modifications.
Most tuner performance software is user-friendly and often features plug-n-play installation that connects directly to the On-Board Diagnostics (OBD) port and even comes programmed with customizable tunes. These are some of the parameters that can be adjusted.
The spark plug in a cylinder fires between 10 and 30 degrees (angle of the crankshaft to the center of the cylinder) before top dead center (TDC). Ideally, it is set to produce the maximum pressure pushing down the piston when the crankshaft is between 5 and 10 degrees after TDC and burning of the A/F mixture is complete at about 15-20 degrees after TDC.
Engineers set the timing based on many factors including fuel type, engine RPM, temperature, geometry, and air/fuel ratio. If the ignition timing is set too soon, the maximum pressure can occur before the piston reaches the top of the cylinder which is counterproductive, and the engine may knock. If not properly addressed, knock can easily ruin an engine. If the spark plug fires too late, energy is wasted.
Manufacturers keep the timing in a safe range, one that reduces the possibility of knock but does not necessarily produce the maximum power. The ECU can be re-programmed to set the timing and gain the extra horsepower the conservative manufacturers leave behind.
Gasoline requires 14.7 grams of air for every gram of fuel for burning. According to Society of Automotive Engineers (SAE), maximum power is generated at an AFR of 12.5:1, while maximum thermal efficiency is achieved at an AFR of about 16:1.
Although manufacturers produce vehicles with desirable high horsepower and torque ratings, they are limited by efficiency standards and government emissions regulations. On new vehicles, the compromise sacrifices power for better fuel economy. Tuning can change the AFR parameter to generate more power.
Several factors must be considered for AFR tuning. In the case of a turbocharged engine, for example, an AFR may be set under 12.5:1 to reduce combustion chamber temperatures and assure system reliability. Fuel economy is significantly sacrificed when power and reliability take priority.
On a forced induction engine, adding boost via the ECU is a simple method of increasing power. Manufacturers tune factory supplied turbos on trucks to keep boost levels reliable and efficient. Increased boost means more air packed into the cylinder, more fuel burned, and more power generated.
Additional boost, however, increases pressure, heat in the cylinders, and stress, therefore reducing the engine’s longevity. An excessive boost may require an upgrade to some internal components.
Factory set limits for RPM and top speed can be modified to increase the engine redline, however, with some precautions. Manufacturers set RPM and top speed limits for practical and safety reasons. The engine may be incapable of flowing sufficient air at higher speeds, the valve train may not keep up with the airflow requirements, or it may not achieve higher RPMs reliably.
Engine Performance Upgrades
Several other methods are commonly used to increase horsepower and torque. The addition of these devices usually requires a re-tuning of the ECU for optimum performance.
- A cold air intake supplies denser air with more oxygen to produce more power.
- A large diameter throttle body with bigger flaps to increase airflow.
- An exhaust header augments the vehicle’s performance by moving air faster and more effectively.
- A high-flow catalytic converter reduces emissions like a stock converter but does it at a higher airflow rate.
- A high-flow cat-back exhaust system replaces the restrictive stock muffler and factory exhaust pipe to increase flow and boost engine performance.
- Forced induction (superchargers & turbochargers) compresses the air flowing into the engine and can increase horsepower and torque by over 50%.
With the extra power available from reprogramming the ECU or adding other upgrade devices, a pickup truck is well-equipped to handle almost any towing requirement. Here are some things to consider before hooking up the trailer.
Even with the extra horsepower and torque from aftermarket upgrades, a pickup truck owner must be familiar with towing limits. The most important number is the truck’s gross combined weight rating (GCWR), which is the total amount of weight allowed for the entire rig including the vehicle, cargo, occupants, and everything in the trailer. The ratings can be found on the vehicle manufacturer’s website or a government-mandated sticker on the inside of the driver’s door.
As an example the RAM 1500 5.7L V8 HEMI, Standard cab, 6‘4” box, 4X4 has a Gross Vehicle Weight Rating (GVWR) of 6350 lbs., a payload of 1390 lbs. and a Gross Combined Weight Rating (GCWR) of 14,350 lbs.
The tongue weight or the amount of trailer weight that rests on the hitch is significant and should be about 10% of the trailer’s weight. Too little or too much weight affects the truck’s controllability resulting in swaying or difficult steering.
To avoid a disastrous, disconnect during travel, the proper size hitch ball should be used to attach the trailer. A pin or lock will keep it latched.
With the correct hitch, the trailer will be level when attached to the vehicle. Safety chains should always be used. Check the brake, running, hazard, and turn signal lights before departure.
A high-quality proportional electronic brake system with brake controller is essential for hauling a trailer with a heavy load. The system balances the braking between the tow vehicle and the trailer. The gain may be regulated to find the optimal setting where the trailer is not dragging the truck down nor is the truck doing all the braking.
Aftermarket tuners for pickup trucks can provide, with or without other upgrades, the extra power that makes towing heavy loads easier. Even without a trailer attached the improved performance of a finely tuned engine can bring a smile to the face of its driver.