There are two styles of electronic boost control:

Bleed and Intercept.

Bleed mode (like your factory system works) uses a set of restrictors and a solenoid to pulse off a metered amount of the signal from the wastegate actuator.

Let's digress.

An actuator responds to pressure by opening when a set amount of incoming pressure exceeds the spring tension working against it. So, if you have an 8PSI spring, at 8 it will start to crack the wastegate open.

When you "bleed off" a portion of that signal pressure, you can delay the addition of a portion of that signal pressure.

Now, by virtue of how that works, you have a much more stable and steady control of boost because it's gradual. But, since a portion of the signal pressure is always reaching the actuator, it will start to crack open that much sooner.

That's where intercept comes in.

In an intercepted signal, the solenoid is plumbed so that when it's energized it completely stops the signal that reaches the actuator.

Benefit? Well to begin with since you're completely removed all pressure from the wastegate spring, the tension in the spring will keep the gate closed that much tighter, allowing for the car to spool faster since the door is not "loose" but securely closed against the exhaust housing.

Caveats? Yes. By virtue of the sensitivity of a system like that, everything happens much much faster. Without a proper understanding of the boost control logic and dynamics system, you'll get boost control that hunts and cycles.

Unfortunately, many people will prefer to use a MBC due to a lack of understanding of factory boost control.

IMO, MBC's are reckless, and here's why.

To begin with, focus on one key word... "Manual". If the weather changes, elevation changes, barometric pressure changes, so does your boost. So does the rise in boost, as well as how well it holds or doesn't hold near redline.

Historically, if you wanted to run 20 PSI at redline, you had to dial up the boost control to something like 23 in the midrange to run your 20 at redline. That's because a manual boost controller doesn't have any closed loop provision from attempting to compensate for VE changes and compressor inefficiencies that cause boost to drop in the first place.

In the electronic world (Let's use an AVC-R for an example) you will notice that all closed loop controllers will want to run less of a duty cycle to reach their targets at lower airflow point, and then automatically start to dial themselves up as RPM increases since the airflow consumption is requiring the wastegate to close more and more; forcing the turbine to spin faster to keep the void compressed with air.

Take a simple EBC one step further and move to a MAF based system and you (by virtue of how MAF naturally works) automatically built in compensations for temperature, humidity, barometric pressure, and even a bad tank of gas to force the car to cut boost out in an emergency.

HTH!

 

Which one would you recommend? What would the upgrade be from our stock MAF and who sells it?

I need to know because I don't know (NOOB).

Thanks

 

Perhaps I misunderstand the question.

The Mass air flow sensor on the car really doesn't become a limitation until over 400 WHP, from my testing.

Jorge (RiftsWRX)
www.ProjectWRX.com

 

yeah, but the jdm one is better right? do you know where you can get one?

 

Honestly, I can't objectively answer that. At P&L we're just starting to really tune them, and those are not something we've had to swap.

Are you sure you're not referring to the JDM MAP sensor?

Jorge (RiftsWRX)
www.ProjectWRX.com

 

Damn! I feel stupid. Yes. That is what I was refering too.

 

Well, since every major system in he car relies on it's MAF sensor input, why would it really matter? Short of logging, I can't see the benefit of the larger MAP sensor.

HTH!

Jorge (RiftsWRX)
www.ProjectWRX.com