[百問] What is the turbo to increase? (Part 2)Introduction to the Principle of Turbo Upgrade

Question 3: What are the ways to increase the turbo?

At present, there are two main ways to increase the turbine. The first is to replace the original turbine with a larger turbine with a higher air volume. This modification is a common practice in the past, and the modification effect is obvious. The disadvantage lies in the surrounding system. It should also be adjusted together, such as the exhaust head section, Down Pipe, intake pipe, etc. If the upgrade is too large, even the oil supply and cooling system need to be strengthened to ensure the normal operation of the engine, and this method is currently Also because the original turbine engine peripheral cooling pipeline is quite complicated, and the turbine head section of some vehicles is also integrated with the engine upper seat, so we want to obtain more horsepower by replacing a large turbine with a different shape and volume than the original factory. This approach became increasingly unfeasible, so another technique to enlarge the turbine was started.

Another emerging way to enlarge the turbine is to process the original turbine, first increase the diameter of the intake and exhaust casings, and then replace the forged blades with larger diameters, so that the center shaft seat can be moved without moving. In this case, increase the air output of the turbine. The reason for this is that there is no need to manufacture an additional exhaust head section, and the oil and water pipelines provided by the original factory can continue to be used. Therefore, processing and enlarging the original turbine will be a faster and less cost-effective approach. , including BMW, VAG, Suzuki, Honda and GT-R R35 and other engines and models, can use this method to increase the turbine to increase the air output.

In addition to the various turbo enlargement techniques mentioned above, the Hybrid turbo (hybrid turbo) is also a popular way to increase in the past. The so-called hybrid turbo refers to the use of a large intake side and a small exhaust side to combine two completely different turbos to create a brand new turbo. The purpose of this is to: It is hoped that an engine with a smaller displacement can be used to operate the larger blades on the intake side to achieve the purpose of higher air output, and take into account the response of low speed (small exhaust blades are easier to push).

Take Trust's TD05H Turbine as an example. It is a TD05 drive wheel combined with a TD06 compression wheel, so it has both the torque of the TD05 and the horsepower of the TD06. However, the ratio of this matching method should not be too extreme, and it is easy to discharge pressure. For the problem of rising and melting the blades, it is best to use the Waste Gate exhaust pressure relief valve with a large exhaust gas release capacity to quickly release the exhaust pressure at high speeds to reduce the high temperature problem caused by the accumulation of exhaust temperature.

Question 4: What are the precautions when increasing the turbo?

Depending on the size of the turbine, the size of the turbine must be determined according to the user's own requirements, because the larger the size of the turbine itself, the more air can be supplied to the engine, but the relative exhaust pressure used to drive the turbine is also must increase. If the turbo cannot be rotated quickly at low rpm, obvious turbo lag will occur. Therefore, if you want to replace a large-sized Turbo to exert a full supercharging effect, enough engine exhaust is one of the basic elements. .

In addition to the size and capacity of the Turbo itself, the A/R value is also an important parameter that affects the supercharging response. A is equal to the diameter of the Turbo outlet, and R is equal to the distance from the center of the intake turbine to the center of the air outlet. The inner diameter is 50mm, the distance from the intake impeller to the center of the air outlet is 62.5mm, and the A/R value is 0.8. The value of this value is related to the timing of supercharging and the performance of high-speed power. Usually, the turbine with a small A/R value The turbo response is faster in the low-rev range, but the output resistance is limited by the outlet resistance after the speed increases. The turbo with a relatively large A/R value has a poor response in the low-speed range. When the speed is increased, it can send a larger output. air volume.

From the point of view of the rationale wheel, as long as the exhaust gas discharged from the engine is enough to drive the turbine, the larger the turbine and the higher the boost value, the better the efficiency of the engine, but in reality, the turbo engine has high temperature, high pressure and high friction. The test of how to make the engine generate sufficient torque at medium and low speed, and indeed exert maximum horsepower at high speed, is the most important premise when modifying the Turbo. If it depends on the price, there is no need to consider the above. various conditions. If the car owner considers the delicate and smoothness and oil pressure, the size of the Turbo itself, the A/R value and the boost value must be set at a conservative low value, but it cannot expect a strong output performance; if it is used to challenge In terms of results, a turbo with a large A/R value is the first choice, but at this time, you have to face the choice of strengthening the internal parts of the engine, increasing the displacement, and other items that require money and time accumulation, so you need to play a high-horsepower engine. Setting, financial resources still decide everything.