How Much HP Can You Gain From a Dyno Tune?

You heard the story – dyno tuning increases horsepower! But how much horsepower can you get – really? And how does it even work? What goes down when you bring your car to a dyno tuning. Let’s cover them in this article. 

To give a ballpark figure – if you are on a stock car, you could probably gain 10-15 horsepower from a dyno tune. However, if you are running on performance parts like exhaust and turbo, then 50 horsepower gain is possible – even more depending on your engine and what performance parts you equip.

Dyno and tuning are actually two different things. Dyno means dynamometer – a tool used to measure the statistics of your car like horsepower and torque. Whereas tuning means changing the values of your car computer so it behaves differently. Combined together, dyno tuning means adjusting the behavior of your car by tuning and immediately testing using a dyno to see the results. A little too much to digest maybe? Ok. Let’s break it down a bit. 🙂

What is the function of a car’s computer?

A quick recap – a car engine delivers power to the wheels by igniting fuel and creating combustion. These combustion need oxygen to exist. The bigger the combustion, the more oxygen it needs. Because of this, more power requires more fuel and oxygen. 

In the olden days, a car is very mechanical. The gas pedal was mechanically connected to the throttle. The more you press the pedal, the wider the throttle opens – allowing more air and fuel to enter into the combustion chamber. This was simple but it lacks control. What if I told you – you don’t always want the increase in power to be linear? Meaning – If I press the paddle down 50%, I should receive 50% of my car’s power. 

Consider this: when you are accelerating at a low speed on a corner, you don’t want the acceleration to be very powerful – this will create extreme wheel spins that could be dangerous. Plus it wears the tire much quicker. Instead, acceleration should be kept low when at low speed and then increase at a higher speed.  These kinds of power output would not be possible in the olden days.

Enter the ECU – a car’s computer that controls how much power is delivered using various factors and calculations. An ECU takes input from various sensors in the car such as air flow sensors, oxygen sensors and temperature sensors. It then performs calculations and makes decisions by referring to the lookup table. For instance, when air is flowing in at 50 grams / second, then inject this amount of fuel into the combustion chamber.

How Does Tuning Work? 

Tuning a car means changing the values of ECU’s lookup table. If a car is currently producing 80Nm of torque from 8000 RPM, then by tuning – we can change the target torque to be 90Nm instead. Of course this extra performance will come at the expense of increased fuel consumption and potentially more wear and tear problems. But you get the idea – tuning is all about changing the values in the lookup table and then testing it with the dyno to see if it does perform as expected. 

Tuning does not necessarily mean extra performance. You are free to tune your car however you want. You could tune your car for maximum fuel efficiency, or tune your car so that it’s suitable to perform at higher altitude weather, or even tune it for a higher top speed. The list is endless. Racing teams tune their cars on a daily basis to ensure the car will perform at its best for the particular race track on that day. 

How Does Dyno Work?

I told you a dyno measures a car’s performance right? But how exactly? 🙂 There are many types of dyno. Some dynos like engine dyno require you to remove the engine from your car and hook it up to the dyno for testing – we won’t talk about this one. Instead, we will discuss how a chassis dyno works. 

Chassis dyno is the typical dyno that you see in the car tuning world. The whole car is loaded on the dyno – where the tyres are positioned right on the dyno’s rollers. The dyno rollers are hooked up to sensors which read the amount of force exerted on the rollers. Obviously – more force means higher horsepower. 

Also, when your car is hooked up on a dyno, it is not actually moving – only the tyres are. This means there’s no wind to cool down the surrounding temperature – which heats up pretty quickly, causing your car to suck in hot air and have inaccurate reading. We obviously don’t want that, do we ?!. This is why a dyno also requires a good cooling system to cool down the area and ensure the dyno tests are always accurate. 

All in all, dyno tuning means that you let your car run on a dyno to get some reading. Then use your computers to adjust values in the lookup table and then let your car run again to test the changes. Tuning does not sound so cool any more, does it? What if I tell you there’s another type of tuning where you are not stuck in a room and actually on the road? Enter street tuning!

Street tuning is where you adjust the values of your lookup table and then take it on a spin to test it out. This would require you to work outside and preferably on the race track. Some tuners prefer street tuning because it allows them to test the car in a real environment (the dyno can’t replicate everything, right?). It’s also pretty cheap – you don’t need to take your car to the dyno shop and pay for the services. 

That being said,  the majority would still do dyno tuning because it’s safer and does not risk you breaking any law. Plus, you can’t really monitor the reading when you are going at such a high speed. I do not recommend you to perform street tuning. I just want you to know it exists, so you can talk about it with your friends!

Ok – I have talked a bunch. Explaining dyno tuning and how they work. But how exactly can you increase car performance by tuning? What should you tune and what can you tune? Here it goes – the most common things you need to tune to increase performance:

Tuning The Rev Limit

Car manufacturers often limit the rev for safety and regulations. You could tune this value in the lookup table. Either removing it or changing to a higher or lower value. This comes at the cost of wear and tear damages. Driving at high rev can cause a lot of heat to build up in the engine. Constantly doing so will cause wear and tear damages at the least and engine failure at the worse. Proceed with caution!

Tuning The Engine Torque Map

Still remember all the rambling above? About how an ECU controls torque delivery by taking input from sensors and referring to the lookup table? To be more specific, the ECU is referring to the engine torque map –  a long list of tables dictating the torque output based on RPM and how deep you are pushing the pedal. 

To gain more performance, you can tune the values in the engine torque map – providing you with more torque at the higher or lower RPM depending on you and your driving conditions.

Tuning Air-Fuel Ratio

As you should already know – to deliver power, a car needs fuel and oxygen. To achieve an optimal fuel consumption and performance, the air-fuel ratio must also be optimal. Too much fuel and not enough oxygen will cause your car to run rich. Meaning not all injected fuel is burned – causing your fuel consumption to be horrible. On the other hand, too little fuel and a lot of oxygen will cause your car to run lean Meaning there’s not enough fuel to burn – causing your car to under-perform. 

If all you care about is performance, then running a little rich is a good option. You might waste some fuel but you ensure that your car is always running at top performance. This can be done by decreasing the air to fuel ratio in the lookup table.

Tuning Top Speed

Some governments have regulations on the top speed. And to comply, car manufacturers would put a limit on the top speed of their cars. For instance BMW places a top speed limit of 150 mph for a lot of their cars. You could tune the  ECU and change this value – but of course, with the risk of breaking the law and regulations. Maybe don’t fiddle around with this value so much huh? Also, this only applies to high end cars… If you don’t have one (like many of us), then this option is not even available to you!

Many More

Of course there are many more values that you can tune like ignition timing – just to name another. Point is tuning your car can definitely improve performance, torque and horsepower. But exactly how much can you get? Are there any restrictions?

Unfortunately, sky is not the limit. It’s very difficult to give a figure on the horsepower or torque gain. It all really depends on the parts that you equip. If you have installed a lot of performance parts like cold air intake, exhaust and turbo – then tuning your car will definitely gain you a lot of horsepower. 

To give a ballpark figure – if you are on a stock car, you could probably gain 10-15 horsepower from a dyno tune. However, if you are running on performance parts like exhaust and turbo then 50 horsepower gain is possible – even more depending on your engine and what performance parts you equip.

Tuning a stock car will not yield much result in terms of horsepower and torque. The stock parts that you equip do not have much room for horsepower improvement. Although for high end cars – you might be able to see some results because of the limitation by rules and regulations I mentioned above. 

Horsepower aside, you can definitely see improvement in the throttle response and also performance in the low RPM range. You could tune your car to assert more torque at the low RPM area – depending on your preference. Also, as I already mentioned, you could make your car run a little richer. Meaning, your car will inject a little more fuel than usual to ensure peak performance at all times – but at the expense of fuel efficiency.