Hi noob question. From what I understand the MBC is designed to hold boost better and so does the wastegate actuator. So would getting these 2 be redundant? Also I hear the stock EVO X boost controller is just as good if not better than anything after market. Is there a definitive answer to this?

 

All you need is a tune. The computer does a good job controlling boost. The upgraded wastegate just opens later, thus allowing more constant boost figures through the rpm range. I am not sure why so many people go with a MBC when it really is not needed.

 

I always wondered this myself. I noticed a lot of tuners still use MBCs as part of their power upgrades. I guess old habits die hard.

 

So more yuppies buy their parts and the tuners make money. If a tuner tells you need a MBC they are full of poop.

 

I dunno, maybe because being able to change the boost on the fly has some usefullness at times?

 

Or you can just change the map...on the fly.

What's the point of changing boost if you don't change the tune that goes along with it...

 

At road courses I run 24 psi and for street/strip I run 26 psi, honestly it's not such a difference that your tune will be off by more than one load cell. Chances are the 24 psi setting would have slightly more aggressive timing/fuel settings due to lower load but it should still be safer for beating on the car at a road course. I can change the boost with a swich in the cabin and adust both boost levels between 22-30 psi with my current setup. Of course the stock turbo restricts flow at 5500+ so the extra boost only effects the low to mid right now but with my new turbo that will all change.

There is no reason why I can't tune the car to work well at 24-26 PSI on 93 octane and when I want to run 29-30 psi boost just add race gas to compensate. Will it be as good as having a complete tune for race gas, probably not, but it will still deliver more power from the increased boost levels.

I think the built in boost control is quite good, but if you like to tinker with boost levels at all it's not as convenient having to reflash the car every time you want to make a change. Another factor is not everyone will be savvy enough to tune the boost levels of their own car if they get the boost set with an EcuTek Tune or similar. If they do additional mods there are some that may increase (or decrease) the boost levels and then you would be forced to get it retuned and that can cost real $$$. I guess everyone can have their own opinion on the matter.

 

I just noticed that the OP has a "COBB AP w/ Perrin Stage 1" so I'm not sure how easy it is to use that to set boost levels or tune. I'm assuming you have to at least pull over and load a new map which may be good enough depending on what you are after.

 

I thought that MBCs are for holding boost better and to get a better curve? If its just to be able to adjust boost on the fly then its not really what I need. Does this also mean the wastegate actuator is actually for holding boost better?

 

The basic MBC will just be an underhood adjustable boost controller, although some will allow you to change or toggle between boost settings from inside the car. EBC's are the electronic version of them that usually add a few more features at a cost. The built in boost control will allow you to set boost at different RPM points and custom taylor the boost curve barring taper from a weak WGA or flow limits of the turbo.

Basically all boost controll methods are effected by how good the WGA is at holding boost across the rev range, and the stocker tends to taper from 26 psi @ 3000 RPM down to 23 PSI @ 5500 RPM where as an upgraded WGA like the Forge will hold the 26 psi right to 5500 due to a stiffer spring. On the stock turbo you will still get taper from 5500 to 7500 due to the turbo's compressor side running out of flow capacity.

Upgraded turbochargers benefit more from an upgraded WGA and will typically hold boost within 1 psi from 3000 to 7500 where as the stocker would taper down 4-5 psi.

Hope that clears things up.

 

Cool definatly clears things up thanks!

 

I feel there is no need for a mbc so far for the evo x. The stock ecu does a great job of controlling boost. The forge wga does hold boost better through the midrange and topend. We were using the forge wga until we bought the blouch dominator 2.0. That turbo comes with it's own actuator which works even better.

Mbc's will be used down the road on big turbo/built motor setups running 35+psi down the road.