So... What is a Rolling Road? A Rolling Road is simply a tool for measuring horsepower, which is a way we measure power. In fact, horsepower is actually a way of measuring a load of work.

In its simplest form, horsepower means 33,000 foot-pounds of work completed within one minute which means one pound of weight would have to be lifted 33,000 feet in the air within one minute or 330 pounds of weight would have to be lifted 100 feet in the air within one minute.

In was invented by a man named James Watt, who also invented the power unit "watts". He invented horsepower as a way of standardizing the work an average workhorse could do... hence horsepower!

As the unit horsepower was quite easily applied to anything that could move a known weight over a distance and was commonly used, it was continued through the ages and is now most commonly used to quote engine power (and so are watts).

But how do you measure horsepower on an engine?

Well, again it is simply a formula...

Torque x RPM / 5252 = Hp

...and using this formula, it is simple to know how much power an engine produces at a certain RPM point.

But how can you find out how fast an engine is spinning and how much torque it is producing?

Well that where a Rolling Road comes in. A Rolling Road works by applying an opposing force against the output of the engine. By measuring how much resistance the engine provides tells us how much torque that engine is producing. Along with measuring the RPM, we can then apply the formula above and work out the Horsepower that the engine has.

But isn't there anything else a Rolling Road can do?

Well the Rolling Road works by applying force in a controlled manner. As we have complete control over how much force is applied, combined with the split second reaction time that computers can achieve; we can hold an engine at a certain point regardless of the throttle position. This opens up a whole load of possibilities. As we can hold an engine at any point, we can now tune an engine to perfection at every thinkable RPM stage and throttle position - making changes and checking the performance increase/decrease there and then.

Using other measuring equipment alongside the Rolling Road, such as Air/Fuel Ratio meter, we are able to tune right down to point of making sure that the engine is burning fuel 100% efficiently. This is known as "stoichiometrically efficient" as is a term used by chemists to define a perfect burning mix, meaning that when combustion occurs there will be no wasted air or fuel in the mix.

As another by product of the way the Rolling Road works, and by combining all the different measuring devices available; you can use a Rolling Road to diagnose faults and problems. By measuring several things such as A/F Ratio and power output and then comparing it to known values you can test and prove what is going wrong and then work out what is the cause. This can save time and money by ruling out many problems very quickly saving you from having to spend £££ paying a mechanic to find the problem and running the risk of it not being fixed due to not having a Rolling Road to their disposal!

Well that's about it for this explanation of Rolling Roads... If you have anymore queries please feel free to use the contact link on the menu bar and E-Mail enquires department.