All Turbo Charger Turbocharger Efficiency Improvement – How to Choose the Right Turbocharger

Turbocharger Efficiency Improvement – How to Choose the Right Turbocharger

Turbocharger Efficiency Improvement – How to Choose the Right Turbocharger

Thinking of getting a turbocharger but not sure how to go about it? Well, installing an unsuitable turbocharger for your engine isn’t waste of time and money, but could also damage it.  Therefore, understanding your setup and properly tweaking your gear for maximum turbocharger efficiency improvement  is very important.

More isn’t always better – pick the size of turbo that’s ideal for your driving.

Before you begin, you’ll first need to figure out how you’re going to driving most of the time.

If you’re expecting to do most of your driving in an urban centre (i.e. town, city) then your turbocharger probably going to be doing high revs much, and a smaller compressor would be optimum. A large compressor would be counterproductive as the engine won’t be running fast enough to spin the turbine, resulting in a lot of turbo lag.

However, if you’re going to be driving at high speeds a lot (i.e. highways, long stretches of road, racing) a larger compressor will be necessary to accommodate the high gas pressures resulting from higher revs. Putting a smaller compressor against such forces is a good way to damage your turbo and engine.

Find the best turbocharger kits, cleaners and repair kits in Malaysia. Contact APT-Turbo today.  


Turbocharger Efficiency Improvement compressor flow map 1

Diagram of Garrett Turbo Compressor Flow Map; Picture via Justin Sane.

Next, you’re going to have to figure out your turbocharger volumetric efficiency. Tuning a turbo badly will result in a lot of wasted energy in the form of heat and noise.

Using the turbocharger’s Compressor Flow Map (CFM), you can calculate the optimal pressure ratio over airflow at different RPMs (see Justin Sane’s amazing tutorial).

In general, smaller turbochargers are ideal for lower horsepower 4-cylinder engines which are best for urban driving or sprint and stop racing, such as street racing.

Mid-range turbochargers are meant for heavy track racing. The largest turbochargers are used when power is a priority, such as drag racing.

Turbos with Ball Bearings are More Expensive but More Responsive.

Bearings bear the brunt of the force that turbochargers produce. They are used to facilitate the turning of a wheel on an axle while reducing the friction between the two surfaces as much as possible. There are two types of bearings that turbochargers use: ball bearing and standard bearings.

Type of BearingAdvantagesDisadvantages
Ball Bearings- Balls provide smaller point of contact, significantly lower friction, improving wear and tear.
- Power saving.
- Requires less lubricating. Cleaner.
- More efficient, with better responsiveness. Useful in race cars.
- More expensive. Can cause the price a turbocharger to double.
- Far more difficult and expensive to repair.
- Are not designed for heavy loads.
Standard Bearings/Plain Bearings- Contact the axle on a curved flat surface. Higher friction with more wear and tear.
- Cost less.
- Good shock protection.
- More compact and require less housing space.
- Loss of power due to friction.
- Requires lubrication.
- Designed to only carry radial or axial loads only.
Turbocharger Efficiency Improvement ball bearings 1

Ball bearings reduce the friction between moving mechanical parts. In turbochargers they improve the responsiveness of the compressor’s turbine to airflow.

Trim Area to Radius (A/R)

The trim refers to the ratio between the area of the inducer and the exducer. It can be calculated using the formula below:

Turbocharger Efficiency Improvement trim formula 1

Fluid dynamics means that the size of the inducer where air enters the compressor wheel should always be smaller than the exducer, but is larger where the air exits. Basically, the lower the trim the quicker the spool starts spinning, resulting in better responsiveness but at the expense of power; the larger the trim the greater the power boost but takes longer to kick in.

Have a damaged turbocharger? Contact APT-Turbo for turbocharger repair services in Johor Bahru