Kierkegaard

I'm trying to decide if I want to run the GM boost solenoid to control boost or the tried and true Hallman MBC. What are the advantages of the GM unit over the MBC? Can it help hold boost better etc? Only thing keeping me away from the GM unit is the seeming complexity relative to the MBC.
Thanks

Lancematic

iTrader: (10)

You can tune the GM solenoid to raise boost during a pull for a flat boost curve; without the boost tapering off at the end of the run you get with a MBC.

dsmjeffro

iTrader: (4)

gm solinoid all the way with aem you can run a different amount of boost in every gear

Lancematic

iTrader: (10)

+1

UCB

iTrader: (12)

You retain all of the factory safeguards for boost control

Better response, fine tuning the boost curve. You could make it look like a step function if you really wanted

Evo_Jay

iTrader: (17)

The only thing that makes the MBC better then a GM solenoid is that its easier to tune, like one to a few pulls. Gm takes some time to tune.

All other things the GM does better.

Nuked

iTrader: (9)

I assume the GM BCS would adjust for temperature and elevation as well? I know if so that is reason enough for me.

SQ

Erik@MIL.SPEC

iTrader: (94)

GM is just a solenoid. You're using stock boost control (well, ECU-based boost control) with an upgraded solenoid. Closed loop boost control, among other things.

UCB

iTrader: (12)

Its not closed loop boost control, but it still offers more adjustment than the MBC, but yes initially its harder to tune fore

Erik@MIL.SPEC

iTrader: (94)

But isn't there closed loop since you're using ECUflash?

A418t81

iTrader: (5)

No, closed loop implies that the pressure is being measured directly, the ECU infers based on load data from the maf.

Erik@MIL.SPEC

iTrader: (94)

Ok, gotcha. Learn something new everyday.

ALLBLACK-EVO

I would go the GM Solenoid. I almost purchased it last week to for my Motec to control.

One disadvantage with the MBC a friend of mine had his hood up during a car show and some clown adjusted his boost while he wasn't looking.

UCB

iTrader: (12)

Indeed...very few cars use closed loop boost control (I believe the new 335i does however)

In a closed loop system, you basically set a boost level, and the ecu will try to get to that boost level, and raise/lower boost constantly while monitoring boost. So there is feedback from the car that the ecu reacts to.

For evos, you just set the boost level and have to monitor it by other means (ie map sensor), then continue to tune the boost curve until it looks like you want it, hence the need for dynos and such

UCB

iTrader: (12)

another plus of the GM (or any other form of ecu controled boost)

If you run multiple maps, no need to turn a knob each time to raise/lower the boost.