hey guys, just got done introducing myself here earlier and already need to ask a question lol. i have an 05 evo 8 with tbe (with cat), arc intake box, and an hks bov. i know stock boost psi is 19-20 pounds but mine is only goin to about 11-12 pounds. the car runs fine with no hiccups besides a check engine light for running rich. ive checked the bcs and it looks fine so i dunno why its not boostin fully. i may need to check for leaks again... oh and the bov IS recirculated. im new to the evo but not boost so u guys will still know more than me

 

Do a boost leak test and check your wastegate. That is lower then wastegate pressure.

 

I had the same problem, then i got a MBC and a tune and my tuner explained it's because that standard wastegate duty i believe
Don't worry

 

is this occurring during the first couple minutes of driving and then r u able to get full boost? or are u just not ever able to hit full boost?

 

its never gotten above 12 pounds. i figured it was lower than the standard wastegate pressure...i wanna up boost later but i first wanna make sure everything is good mechanically nd get it boosting the stock pressure at least. i dont know the vacuum routing on these cars but ill put as best i can, theres a line going from the compressor housing to the wastegate and t'd off to go to the bcs. then the second line from the bcs is going to the intake tube. is that correct? and thank u guys for the quick help, talk about customer service!

 

What part of Cali are you in, master? Maybe I can suggest someone nearby.

 

Lancaster to be specific, about an hour north of LA. i dont see why i can figure out the prob... maybe i need to get a new fmic kit instead of wasting time on this setup lol

 

Swap on a stock Mitsu metal MR diverter valve. If you bought the car secondhand, then previous owner may have not reconfigured the stock boost control schemata properly. So, for $17 buy a factory boost/vacuum hose assembly which includes the proper restrictor orifices("pills") and "T" with all the correct hose lengths and OEM hose clamps.

 

can anyone suggest someone to look at my car... im only boosting 5lbs now....no idea why...did boost leak test, took off my MBC, put my stock exhaust manifold back on....no idea. good gas mileage, smooth idle, etc....just no power.....please help.. i dunno if its the fuel delivery system possibly....about 4 months ago i threw a code that referenced my fuel system....could that cuase me not to boost??????

 

Are you in Orange Co., California? If so, I'd head on over to Road Race Engineering.I think that they are in Santa Fe Springs.

 

so this diverter valve can be bought at a mitsu parts department? im going to apologize in advance for this but what will the diverter valve do for me? how do u hook it up?

 

btw: im going to go get my brand new MAF because its throwing a service engine soon light . the code was for a rich afr apparently. maybe this could fix it...but im not sure if it will

 

The stock MR diverter valve would be in place of the HKS BOV. The factory valve recirculates the already metered air back into the intake between the MAF and the throttle body.

Anyway, I'd suggest that you get the stock MR metal DV and an ECU flash(tune). Hold off off on the MAF purchase until after the flash. It may not be needed. Also, get the stock factory boost/vacuum hose assembly for $17.

 

and all this can be bought at the dealer? so to clarify all i need is a stock mr diverter valve and factory vacuum hose assembly...

 

checked the codes myself today at work and had a few, one for running rich, IAT hot, wastegate solenoid malfunction and i think that was it. so i cleared the codes after changing the maf (warranty dont worry) to see if they stay off now...