There isn't much you are going to gain.
The ECU has a table of boost pressures inside it, and it will just actuate the turbo to increase or decrease boost to reach the target.
I guess you could divide the ECU into two parts, the fueling and the boost. The power comes from the fueling, and at any point, it will be injecting a specific amount of fuel based on things like pedal position and torque limiters.
Running in parallel to this is the boost side which is increasing or decreasing boost to reach the levels programmed in the ECU.
The only time you would see more power would be if the ECU holds back a little on the fueling as it might produce some smoke.
eg.
Pedal position asks for x mg of diesel,
Torque limiters will set the maximum mg of diesel to be injected,
At the same time, it will be working out boost levels and reaching y mbar of boost.
It will combine these values and see if x mg of diesel is right for the amount of air measured (more boost means more air)
So as long as it isn't at a torque limiter, and there is enough air, it will inject the same amount of fuel whether you are at 0.8 bar of boost or 1.5 bar of boost.
Removing the actuator and using something else to control the boost is likely to put the ECU into a limp mode, which activates quite a low torque limiter for safety.
Getting more air into a diesel doesn't really do a lot, but it allows more fuel to be injected giving more power without smoke.
AFR on a diesel is already on the lean side so no gains from more boost.
About the limit on that car is 1.5bar with stock map sensor.If you use the 320d 150hp you can use up to 2.3bars.
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
BMW Forums : BimmerForums
1.5M posts
270.7K members
Since 2007
A forum community dedicated to BMW owners and enthusiasts. Come join the discussion about performance, modifications, troubleshooting, M series, motorsports, maintenance, and more!