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I recently installed Vrg's FCD and re-routed my MBC to where I can access it more readily. I went for a test drive around the block and was tuning my MBC to run 13psi to see if it worked. Well, moral of the story... i turned the MBC all the way up and all I get it 9 psi tops. What gives?

Seems like the stock waste gate solenoid is controlling things. Did you bypass the stock solenoid? Or did you run inline with the stock solenoid?

What kind of MBC? How is it plumbed? How low can you set the boost?

[quote="BAC5.2"]Seems like the stock waste gate solenoid is controlling things. quote]

The only issue with that theory is our cars run 11psi up here because of the altitude, but that doesn't mean that the solenoid isn't involved...

But our wastegate actuators are 6 psi right? So if he is running wastegate boost then he would have around 6 psi at sea level. So at higher elevations 9 psi might be about right.

The VRG FCD doesn't do anything to control boost, it just alters (clamps) the signal that goes to the ECU from the pressure sensor. So I would think something is wrong with the MBC setup.

Left up to the wastegate actuator, boost will always be about 6 psi gauge.

It does look like $J-MoNeY-$'s stock boost control system is still running things for whatever reason.

vrg3 wrote:Left up to the wastegate actuator, boost will always be about 6 psi gauge.

Uh, ya, true. I was trying to tie in the atmospheric/manifold pressure pressure sensor signal with just manifold pressure. Is it just me or have I been stickin' my foot in my mouth a lot lately?

Heh, we all have those kinds of days...

So you admit he's doing that Vikash?

But yeah, it doesn't sound like the MBC is doing anything, at least to me.

It's a no name MBC off e-bay. It goes as low as 3-4 PSI.

I can turn it down, just not turn it up.

That sounds like your problem. Buying a cheap no-name off of E-Bay.

Invest in a Joe-P MBC and install it correctly.

Uh, that doesn't make any sense.

You shouldn't be able to turn the boost down below wastegate spring pressure.

Where is your boost gauge measuring from?

BAC5.2 wrote:That sounds like your problem. Buying a cheap no-name off of E-Bay.

Invest in a Joe-P MBC and install it correctly.

I can't agree at all. Spending that kind of money on something so simple is just silly.

I'd rather spend 40 bucks on something that is designed to work than 15 bucks on something that some jackass just randomly slapped together.

I agree with THAWA that an expensive MBC isn't worth it.

The Joe P boost controller isn't anything special. You can build the same thing yourself with pieces from the hardware store and less than an hour of work.

I also wouldn't buy one on eBay for the same reason.

But anyway... the type of boost controller isn't $J-MoNeY-$'s problem; no boost controller you can buy can force boost below the level determined by the wastegate spring.

Care to explain to me why spending nearly 4 times as much(depending on if you've got spare parts sitting around) for something that does the exact same thing and will perform at the exact same level automatically makes something better? Also don't buy it form some random jackass, make it yourself.

EDIT: I just looked at joepmbc.com That is exactly like an mbc you would make. What makes you think some random jackass didn't put together your 45 dollar mbc?

People buy STi parts, don't they?

You can make or get cheaper most things from STi, yet people still buy them.

Same goes for almost any major manufacturer.

People will spend $50 on a gauge pod instead of just screwing a gauge to a home made bracket.

Jiffy Lube is the perfect response to what you asked. Changing your oil takes 20 minutes and costs less than $15, yet people are willing to spend twice as much to have Jiffy Lube do it.

Jiffy Lube is a multimillion dollar company. It costs $30 for an oil change. And it takes longer to go to Jiffy Lube than to change your own oil.

I agree, and everything you said falls under what I'm saying. But you still didn't answer my question.

Because it's easier to buy than to make. ESPICALLY if you buy it used.

If you can buy a used Joe-P MBC for $20 shipped, it's easier than building your own for $15 + gas.

you can buy a used diy mbc for shipping...

Guess you got me...

j money, could you get more boost when you didnt have that fcd in?
how does the fcd work? is it a circit type where you spliced it in to the factory fcd? if so that could be your problem.

Boost gauge goes from -30 to + 20 atmospheric pressue.

The weird this is that I can turn it down. I assume that my wastegate is on the fritz.

Yes I could get more boost without the FCD. But then again I had the MBC spliced inline with the stock boost controller. When I moved it so the MBC was doing all the work and not the factory boost controller, that is when I have the problem. And yes I did install it correctly.

Wait -- installing the FCD affected your boost level? Explain more.