I am having the JDM MR blow off valve and Hallman MBC put on this week. I wanted to know what it should be set at? My only other mods are drop in filter, GReddy cat back, crappy Helix intercooler piping, reflash.
Thanks

 

21 psi

 

+1 Definitely no more than 23

 

do u have a boost gauge?

 

You NEED a boost gauge to know what your boosting. Set the MBC all the way to the closed position. You will read around 12psi at WOT. Then start going up on the MBC one full turn at a time and test at WOT. Keep turning it up until you reach 21psi. For boost gauge I highly recomend the Autometer carbon fiber series in the mechanical style. It comes with a red nipple for the bulb and reads -30 thru 30+ psi. Cost $60. Its also the best matching to the interior of the evo too.

 

Sorry, forgot to mention at the same time I am having an autometer mechanical boost gauge and an electronic oil pressure gauge put in an A pillar mount as well.

 

The car is going to feel like a new monster....i was so pleased after the install and the uppage of boost.

 

As an 05, the boost won't be upped that much.

As already mentioned, start the Hallman set to minimum, then gradually increase it until it peaks at 21-22psi in 3rd gear from a low rpm roll-on.

 

Does one complete turn equal an additional pound of boost or does it vary?

 

It varies

 

AC, there is no direct correlation to boost and turns. Just play with it, man. No reason to worry about it now. Just turn it gradually and watch the boost rise, then adjust your turns accordingly until you get it right. Just know that you will see no gain in boost for a while, because it won't actuate above 11psi (minimum) until you've done several full turns. However, don't get impatient and turn it really far at once.

 

So you should set it to spike at around 21 and taper down to 18 or so? Can you not safely have it spike to 23 and taper to 20 or so? I have been wondering myself, I know that stock the car runs 21 psi.

 

do you have a downpipe?

 

No. I am esentially stock with drop in and other non-power mods.

 

No, the stock boost is 20.3psi PEAK with an immediate taper. You don't want to try to run 23psi on pump gas with only a taper to 20-21psi. That's pushing the envelope. With no other mods, though, you don't even want to get close. Without an exhaust, you will have a lot of backpressure, so raising the boost will cause knock.