How much peak power will my car make, what does this figure mean?
The general consensus is the higher the number the better, numbers sell. A 300hp car sounds much better than a 280hp car! But in reality, what can you tell by these numbers?
Peak figures
First of all quoted power and torque numbers are peak figures, they are the highest seen figures on a power or torque curve. They tell you what power and torque a vehicle is making on that dyno but those figures are really only useful for bragging rights at the bar with your friends. For a true indication of how a vehicle will feel and where the benefits of tuning can be seen you need to assess the power and torque curves, as they say its the ‘power under the curve’ that makes the difference.
In the below example there are three power curves, the purple is stock, the red is Revo and the dashed blue line is hypothetical:
On paper, the dashed blue line makes the most power as it peaks nearly 10bhp higher, however from 2400rpm through to 6000rpm the red curve makes a lot more power. At 3500rpm the red curve is 50bhp more than the dashed blue curve. On the road, a car running the red curve (with a lower power output) would be a much quicker car. This is a good example of how a peak number can be very deceptive and not tell the full story. You can see the difference in the area under the curves and how much more the red curve has gained throughout the rev range in comparison to the dashed blue curve.
The full story
The dashed blue line makes the most power as it peaks nearly 10bhp higher, however from 2400rpm through to 6000rpm the red curve makes a lot more power. At 3500rpm the red curve is 50bhp more than the dashed blue curve. On the road, a car running the red curve (with a lower power output) would be a much quicker car. This is a good example of how a peak number can be very deceptive and not tell the full story. You can see the difference in the area under the curves and how much more the red curve has gained throughout the rev range in comparison to the dashed blue curve.
Whilst an understanding of peak figures and power under the curve is important, it’s just as important to understand that rolling road results can and do vary and aren’t always a true representation of what a car will do in the real world for more information click here
