I am trying to understand how the various boost controllers improve performance.

In the stock application, what input is used to map boost levels?

When you add a mbc, is it the same inputs, but a higher boost output, or does the mbc simply hold a max boost pressure regardless of the inputs?

 

I have seen people say do not turn up boost without a tune

 

And MBC creates a differential in pressure between the turbo and waste gate. The stock waste gate opens at 14psi I believe. Say you set the MBC to 20psi according to your boost gauge, it is creating a differential of 6psi so the waste gate thinks its only seeing 14psi and opening when in fact it is seeing 20psi before it starts to bleed off boost.

And yes dont turn the boost up without a tune.

 

Installing MBC bypasses stock boost control solenoid. You are then able to adjust the desired boost pressure, using ball and spring tension. But yes, upping your boost levels should and by that I mean MUST be accompanied with a tune.

 

and till you upgrade your fuel pump on an evo 8

 

Was that your way of explaining MBC boost control? Why not just say it keeps the WG closed until boost reaches the desired boost set point? The Devil is in the details!

 

So, the mbc only controls at what max pressure the waste gate opens?

I agree on the need for a tune. For the mbc's that have a dual setting I am assuming the tune is done for the high boost setting - is that correct?

 

I like to know things, so if someone wants to learn something and I have the knowledge to give them I don't see the problem...no one gives Ted B a hard time

 

So is there any way to have different tunes available on the fly for different boost pressures? What I mean is say I have a street tune at 21psi then I have a track tune for 25psi, is there anyway to have them both to switch between without having to flash the pcm?

 

You can do a 3 port electric boost control solenoid and then set it up with map switching. I dont know exactly how to do that but I know it can be done.

 

Yes, if you let the ECU control boost (like the stock system works, but better) you can patch the ECU for multiple maps, which includes settings for different boost levels.

And yes, when you install a manual boost controller, you bypass the stock boost control system. The ECU still requests the same boost level, but there is nothing to physically control it anymore.

 

Short answer yes. map switching (search), and an EBC or ECU controlled boost

 

so wouldnt an ebc or ecu controlled boost be better then "tricking" the ecu into thinking its seeing a lower boost pressure then it is

 

http://www.maperformance.com/aem-tru...ontroller.html

so a contoller like this would adjust afr and timing per selected boost input?

 

the only time you need two different programs for your ecu is when you run two different types of fuel.

if your car is properly tuned for 25 psi all you have to do is turn down the boost controller to 20 psi. the fuel maps are there. you just cant go higher then what your tuned for.

if your just looking to run two maps for valet mode of something like that it could be done.