Regarding the Removal of Speed Limits

[oreshi0436]

I've unlocked the “speed limiter” in “absolute limits” up to 300, but it seems to plateau around 200. Did I do something wrong, or is there still a limiter that hasn't been unlocked yet? Or is the top speed of a stock BK around 200?

[mituc]

Stock 3MPS BK speed limit is at 250kmph or something, that is about 270kmph on the dash. 200kmph is nothing for these cars, stock or tuned, they will get there pretty fast.
Next time you push it to that speed also log that run and let's see what actually happens, most likely your car developed a small issue over time. Use this dashboard config preset: https://www.dropbox.com/scl/fi/55qyxbqs ... mnqqb&dl=0 - download it and then go to Dashboard -> Presets -> import and load.

[oreshi0436]

I’d like to share two stories here—one good and one embarrassing. The good part is that the car kept accelerating even after it exceeded 200 km/h. The embarrassing part is that I forgot this car has a 6-speed manual transmission, so I might not have shifted past 5th gear. That’s probably why the top speed plateaued at 200 km/h.

[mituc]

That is absolutely fine, a 3MPS BK reaches 200kmph in 5th at about 6000rpm which is the sweet spot on these engines for peak power.
The problem with your car is that it makes probably around 180-190bhp in a good day. Either the EBCS is fitted backwards, or it is stuck closed.

[oreshi0436]

It seems the boost pressure is off too, so I decided to check the EBCS.

[mituc]

It seems the boost pressure is off too, so I decided to check the EBCS.

You can look at several parameters: boost, load, whatever, but the conclusion is the same: your car is far far away from what it should do in terms of power.
In your last log you used 2nd gear which is not the best because there is some torque management in these lower gears, but it will still do since the problem you have is more than obvious.
You should also avoid hitting the rev limit, apart from the obvious mechanical implications, your problem can also be caused by a blockage in the exhaust (shattered catalytic converter, collapsed resonator) so banging the engine on the rev limiter is far from being the best idea.

Since the manifold pressure (or, boost if you like to speak in differential pressures rather than absolute) seems to match the turbo spring rate which makes me think it's still the EBCS or boost control system that is causing the problem. To recap:
1. swapped EBCS lines. The wastegate actuator line should connect to the lower port of the EBCS (closer to the electrical connector) and the intake line should be connected to the top nipple on the EBCS;
2. blocked/collapsed EBCS-to-intake line or wastegate actuator to EBCS;
3. stuck closed EBCS.

Possible solutions:
1. fix the 1, 2 or 3 above (or all, since they may be all happening at the same time);
2. go to a 3-port EBCS approach and get the car tuned properly for it (I can give you some insights on that) to get rid of the potential tired EBCS and rotted lines.

The possible EBCS issue doesn't rule out a problem with your exhaust. But fixing the EBCS or even replacing it is trivial and can be done in one hour in front the of the house, while any exhaust work can be a lot more complicated, especially with old metal piping with bolts/nuts that were not touched in 20 years.