Volvo 940 Turbo Tuning - Cheaply get more power from a B230
A brief introduction to the Volvo B230 turbo engine
The Volvo B230 engine is also known as a "Red Block"; as the name suggests, it owes this to its color. Volvo's B230 (B230FK and B230FT) engine is an 8-valve 2.3L turbocharged engine that delivers 135hp (B230FK LPT) or 165hp (B230FT HPT) as standard.
The difference between the B230FK and the B230FT lies in the wastegate actuator, also known as the pressure box. This ensures that the B230FK turbo produces a maximum pressure of approximately 0.35 bar, while the B230FT produces 0.6 bar of turbo pressure. The engines are otherwise completely identical.
Getting more power from the Volvo 940 B230 turbo engine
Before extracting more power from the Volvo 940 B230 turbo, it is crucial to establish a solid foundation. You achieve this by giving your Volvo 940 with a B230FK/FT engine a so-called Stage 0 tune-up.
Volvo 940 B230 Stage 0 Tune-Up
A Stage 0 tune-up involves performing major maintenance on the engine and peripheral components that will experience increased wear with higher power output. Another reason for a Stage 0 tune-up is to establish a good baseline for the engine. Therefore, replace the following items: engine oil, spark plugs, air filter, transmission oil, and any other items that frequently fail on a Volvo 940. These include the ignition module located against the side panel, the fuel relay which sometimes malfunctions, or the crankshaft position sensor.
After the Stage 0 tune-up, or simply put, major maintenance, the Volvo 940 is ready for more power.
Volvo 940 B230 FK/FT - 175HP Boost controller + Turbo pressure gauge (Budget €100.00)
As stated earlier, the B230FK and B230FT are identical except for the turbo pressure box. The way the B230FT generates more power is by pumping more air (0.6 bar instead of 0.35 bar) into the cylinder chamber while injecting more fuel. Knowing this, you can then say that a 135HP B230FK engine can also be boosted to 165HP; and that is true. The standard ECU (Engine Control Unit), which controls the injection and fuel system, can handle up to about 0.7 bar of turbo pressure. Above that, under heavy load, too lean a mixture can be injected, which can cause damage to the engine due to excessive heat and potentially detonation. Detonation is the premature ignition of a mixture without a spark plug.
Increasing the turbo pressure on a Volvo 940 with a B230 engine is very simple. This can be done with a manual boost controller. This small device causes the air (turbo pressure) going to the pressure box to bleed off slightly, causing the pressure box to activate only at a higher pressure.
Brief explanation of pressure box/wastegate:
A turbo is driven by exhaust gases leaving the engine. These gases pass through the turbine housing, which spools up the turbocharger, creating overpressure in the compressor housing. If the turbo rotates faster due to more exhaust gas passing the turbine wheel in the turbine housing, more turbo pressure (overpressure) will also be created. To ensure that this pressure stays within acceptable limits, turbocharger manufacturers have built in valves (wastegates). This valve ensures that exhaust gases no longer pass through the turbine housing but are discharged directly into the exhaust, which slows down the turbo.
The valve is controlled by a wastegate actuator, often called the pressure box in the Netherlands. From a certain turbo pressure, a rod pushes the valve further and further open until it is fully open, and a significant portion of the exhaust gases go directly into the exhaust, thus "braking" the turbo.
Mounting a Boost Controller and Turbo Pressure Gauge - Increase Turbo Pressure
Mounting a boost controller on a Volvo 740/940 is relatively easy and will take about 30 minutes. As stated earlier, with the original Volvo 740 and Volvo 940 ECU, there is a limit to the turbo pressure. To stay within this limit, a turbo pressure gauge will also need to be connected. This way, it is possible to accurately read the turbo pressure, and the boost controller can be set correctly.
Below is an image showing how to connect the boost controller.
Originally, a hose goes from the compressor housing on the turbo directly to the wastegate actuator or pressure box. This hose should be disconnected so that a tee piece can be inserted. This tee goes back to the pressure box and to the boost controller. The boost controller has a set screw that controls how much pressure will bleed out, and thus determines how much turbo pressure will be created because the pressure box opens later and therefore less exhaust gas "leaks out."
Adjusting the boost controller
Each boost controller comes with an instruction manual detailing how to adjust it. The operation is generally the same: turning the knob all the way in results in original turbo pressure, and all the way out results in maximum turbo pressure. To begin, it is wise to turn the boost controller all the way in and then loosen it by 1 turn. Then, go for a drive so that the engine can reach operating temperature. Once it is up to temperature, you can accelerate at full throttle and simultaneously observe the turbo pressure gauge. The turbo should now deliver more pressure than original, but not yet the desired pressure of 0.7 bar.
Turn the adjusting screw ever so slightly further and conduct a test drive until the turbo pressure gauge reads about 0.7 bar. With this turbo pressure, the Volvo B230 engine will feel significantly faster and also produce more power than when it came from the factory.
More power and more turbo pressure!
The installation is complete, and you can start enjoying the beneficial extra power your Volvo 740/940 will now provide.
Keep in mind that the more power demanded of the engine, the more important maintenance will become. Therefore, always give the Volvo timely service so that it can be driven for a long time to come.
Disclaimer:
LucaCarMods cannot be held liable nor is it responsible for any damages caused by performing this modification.