Turbo lag doesn’t have to kill the fun.
The word turbocharger sounds cooler than it really is. In earlier days it was a good way for tuners to squeeze more power out of a stock engine without committing to a swap or rebuild. But now that the EPA is cracking its whip on previously displacement-happy car manufacturers, the word has become synonymous with performance-lite. It’s not that spooling exhaust-powered air compressors don’t deliver on the necessary power promise, but there are some compromises involved.
The turbocharged BMW M4 is criticized for its emotionless engine note and despite leaps in the technology, most turbocharged engines have a detectable amount of lag. It doesn’t seem to hinder acceleration on cars like the McLaren P1 or the aforementioned M4, but it’s still important to find out how a turbocharged car differs when lined up next to a naturally aspirated competitor. To find out, Car and Driver recently got a four-cylinder EcoBoost Mustang and a V6 Chevrolet Camaro to test exactly how acceleration is affected by the Mustang’s need to build up boost pressure. To justify the test, C & D cited the fact that most engines have their horsepower levels rated when the engine has been spinning at a certain RPM for a while.
This gives a turbocharged car plenty of time to build up the exhaust pressure needed to crank out the extra ponies. An acceleration test would sort this out. Both cars were kept in fourth gear (the Camaro and Mustang have a fourth gear ratio with only 0.3% of difference, making sure differences in the transmission don’t skew results) during the test. After trying acceleration from 1,500 RPM, 2,500 RPM and 3,500 RPM, it was found that the lower the RPM, the longer it took the Mustang to catch up to the Camaro. Despite flat torque curves that turbocharged engines offer, it’s still important to downshift before mashing the throttle for optimal acceleration times. There may be no replacement for displacement, but turbines can still be fun.