General question...why IS boost control so hard?

[AutoEuphoria]

In general, why is boost control so difficult on these cars? Seems like even a bone stock MS3 will have inconsistent boost...inconsistent between gears, inconsistent in the same gear on different days or different times of the day. A MBC usually makes it worse, and even with a Cobb AP the boost seems to be all over the place.

I've had a lot of turbo cars in the past (5, if I recall correctly) and none of them have had issues holding specific boost pressure in any gear, any day of the week, any weather, and any time of the day. So what is so different with these cars that makes things so inconsistent, and is there a way to change that?

[daonly1around]

not up to par waste gate? bad BPV/BOV... i donno

[Speed3Rookie]

Read the thread on the "other" site titled "standback tuning for dummies". There is a wealth of tuning info about these cars. It contains a few theories that's relative to your question.

[AutoEuphoria]

Well, in my case the BPV has been changed, and it still does it...so I wouldn't think it was the stock BPV causing the issue. Possibly the wastegate, since it does happen with (stock boost control) and without (MBC) the boost control solenoid

[derspi]

Because the ECU is smarter than us.

[AutoEuphoria]

apparently not if it can't keep the boost consistent LOL

[hectik1]

apparently not if it can't keep the boost consistent LOLIt isn't the fact it is inconsistent, it is the fact the ECU is constantly adjusting and controlling boost according to the conditions at the time.

[derspi]

apparently not if it can't keep the boost consistent LOL

What the heck does "consistent boost" have to do with anything? The ECU could care less what boost #s you want or expect. It's looking for many things and like someone else mentioned, there are many variables that will affect how it believes will arrive at consistent PERFORMANCE. Getting the same boost readings when the temps are 100 degrees and 40 degrees outside doesn't constitute as consistent when the air is cooler and denser.

And to the ECU, performance includes self preservation, emissions as well as overall power output. So yeah, most definitely, the ECU is smarter than us.

[PCspeed3]

As Kain said in another post, cars just keep getting more complex and get less and less mod friendly, its a damn shame mr bond.

[spdjnke]

There is a very simple answer actually, it's called DISI. That's why. turn on, turn off, this car works just like karate kid, the inconsistant fuel pressure from the damn pump is the main reason, that's all I can say.