Hey, got a question. Lookin into a MBC. Im lookin at the hallman. The Bushur site says that they suggest getting an intake and exhaust system before getting a boost controller. I have the hks hi-power cat back and a (basically short ram) custom intake, with a ssq bov. My boost guage reads like 15 pounds in 1st and second, while in 3rd I get about 17 pounds, in 4th I get about 18-19 pounds, and in 5th about 16-17 again. So anyways, I want to have my boost at about 20 psi. So if my 3rd is already almost at 20, and I have a cat-delete on the way, what is the point in a mbc. will it help to raise the other gear boost levels while not overboostin me in the high gears? Or will I see less taper or faster spool because it is the resistance type bc, rather than the bleed type that comes stock? Is it worth my money? or should I just free up the exhaust a little more to acheive my boost goals? (btw while Im asking, could it be that I am getting incorrect boost readings because I connected my guage to the same manifold pressure line that the bov is connected to? I notice everyone else uses the fuel pressure thingy line with the wrap around it.)
any help would be nice, my friend just bought an 05 sti and I want to show him up, but dont wanna fork over the money if Im not going to get anything out of it aside from filling up with tolulene and jumpin the boost to like 22.

 

It will help the boost in the lower gears. The reason why the boost jumps around is because of the load on the engine. There is a good thread on this. I would get a Hallman mbc or a ebc. My Greddy boost controller has 2 different settings so I can prevent the boost change in different gears. A tune would also help this.

 

so how does the greddy keep the boost consistant between gears? Maybe Ill give EBC's another look.

 

also, how will I get boost in lower gears without raising it in higher ones? Again, could my boost guage setup have anything to do with anything?

 

ttt, anyone that can answer this?

 

anyone?

 

Like someone else mentioned, boost is dependant upon load. There's more load put apon the engine in the higher gears and there is on the lower gears.

But for my car, I got full boost in all my gears. Considering how short 1st gear is, are you sure you're at WOT when looking at the gauge? Any hesitation or lift will lead to a lower boost reading. Have a friend watch the boost gauge while you drive and concentrate on the tach. You could be actually getting to 19.5 psi.

The other possibility is your ecu is limiting boost in the lower gears. A lot of cars have this 'feature'. The WRX comes to mind. What year is your car again? Mitsu could have implemented this in later ecu programming. Did you flash the ecu for the misfire update?

By switching to a MBC, you'll bypass the ecu/solenoid altogether, and your boost will reach whatever levels you set it to, unless you have a bigger turbo. With the larger turbo, you may not be in gear long enough to put enough load to get the boost really high.