Dynojet and Mustang dynos are popular tools for measuring a car’s horsepower and torque. However, significant differences exist in their readings, often leading to confusion and debate among car enthusiasts. This article explores the key distinctions between Dynojet and Mustang dynos, examining their accuracy and explaining why results can vary significantly.
Understanding Dynojet Dynos
Dynojet dynos are known for generating higher horsepower and torque numbers compared to other types. This is primarily due to their inertia-based design. A Dynojet dyno measures the time it takes for a vehicle’s wheels to accelerate a heavy drum, using this information to calculate horsepower and torque. Because of this methodology, Dynojet readings often appear inflated. However, they consistently deliver higher numbers, making them popular for marketing and boasting impressive performance figures.
Exploring Mustang Dynos
Mustang dynos, in contrast, utilize a load-bearing design. They apply a controlled resistance to the vehicle’s wheels, simulating real-world driving conditions more accurately. This resistance, measured in pounds, allows the dyno to calculate horsepower and torque based on the force required to overcome the load. Consequently, Mustang dyno readings typically yield lower, but arguably more realistic, horsepower and torque figures compared to Dynojet dynos. This difference stems from the Mustang dyno’s ability to account for drivetrain losses, which are not as effectively captured by the inertia-based Dynojet system.
Comparing Dyno Results: A Case Study
A prime example of this discrepancy can be seen with the Dodge Hellcat engine. SAE certified testing on an engine dyno rated the Hellcat at 714 hp. Factoring in estimated 20% drivetrain loss, rear-wheel horsepower (rwhp) should be around 571. Mustang dynos often reflect numbers in the 560-580 rwhp range, aligning closely with the calculated estimate. Dynojet results, however, frequently show 650-670 rwhp. This significant difference highlights the inherent variations between the two dyno types. While a Dynojet reading might suggest a much higher crank horsepower, it’s crucial to remember the context of these measurements.
The True Value of Dyno Testing
While the baseline numbers might differ significantly between Dynojet and Mustang dynos, their real value lies in measuring performance changes after modifications. Whether a tune increases horsepower by 50 rwhp on a Dynojet or a Mustang dyno, the gain remains consistent. The dyno serves as a reliable tool to quantify the impact of upgrades, irrespective of the baseline numbers. Therefore, focusing on the delta – the change in performance – provides the most valuable insight when using a dyno for tuning and modifications.
Conclusion: Choosing the Right Dyno
Ultimately, the “best” dyno depends on the intended purpose. Dynojet dynos offer consistently high numbers, often favored for marketing purposes. Mustang dynos provide more realistic, load-based results, better reflecting real-world performance. Understanding these fundamental differences allows for a more informed interpretation of dyno results, empowering car enthusiasts to accurately assess vehicle performance and modifications.
