How Does Tuning a Stock Car Increase Power?
Tuning is the process by which a car’s engine control unit is reprogrammed to adjust air/fuel ratios (AFRs) and cylinder detonation timing. The end results provide more torque and horsepower than the manufacturer released the car with. You might think drivers install aftermarket modifications to the intake or exhaust before tuning to provide a relatively large power boost. How does tuning a car with no modifications increase its power?
The question was recently posed on r/cars, with dozens of explanatory responses. While it seems complex, the reasoning behind and the process for tuning in general is actually fairly straightforward.
Manufacturers are bound to certain parameters when releasing models to the public. Mainly, these are emissions regulations, vehicle longevity standards, and fuel economy expectations.
A lot of cars are “detuned” so the engine’s true power output is capped lower than true spec to fulfiil emissions and consumer standards.
For instance, if a high performance engine is fully tuned for max hp and torque, the longer you run the engine at a high rpm, the faster you’ll wear it or other components out. You’ll also obliterate any solid fuel economy numbers that came factory.
You can tune to boost your car’s base hp and torque without mods
Some folks can boost their car’s base horsepower and torque by 20-40% with a tune, sans mods. It just depends on the car, the equipment, and who’s tuning.
The process involves monitoring the car’s standard performance at certain RPMs. After establishing a baseline, air/fuel ratios are adjusted to avoid rich (too much fuel) or lean (not enough fuel) conditions. Then, timing is advanced to ignite the combustion chambers ahead of standard spec, giving a longer combustion period. The combination will provide increased horsepower and torque.
YouTuber Four Eyes posted a great informational vid a couple of years back on how much of a difference tuning his factory 2000 Dodge Viper made. It’s embedded below.
He brought the car to Street To Sand, an performance shop with a dyno tuner. After running several trials, they settled on AFR and advanced timing parameters.
How did tuning boost the non-modded Viper’s output? Well, not by much.
The driver shows us that before tuning, the Viper went from 30 to 80 mph in 5.93 seconds. After tuning, it got from 30 to 80 mph in 5.5 seconds. Overall, tuning gave almost 7% additional horsepower and slightly more than 7% torque at 4,000 rpm. If anything, the video is super helpful for understanding the process.
Most stock cars won’t release much additional power with a stage one tune. It’s best to contact a professional who has the experience and equipment to best align your expectations to the condition and capability of your vehicle.
Source: Prestige Auto Works
