The word is to not exceed 16 psi on a stock engine. I have a DNA MBC and 4EAT tranny with max boost in fourth at about 15.5 psi (Between .1 and .11 Mpa) And dont forget about PT/FB (partial throttle/full boost) Without the stock boost controller to watch the pressure, it doesnt know how much to richen or lean the fuel. Except when your WOT then its ok. Just make sure you get a boost gauge. And dont go over 7psi unless your floored. Im soon to get a Vishnu dyno tune which will take care of my PT/FB. Then no more having to watchg the boost gauge.

Hope this helps

Darren

 

im running 16lbs on mine, with a up pipe and turbo back. Its sorta a pain in the @** because boost changes if it gets colder. I accidentally overboosted the other night when it got cold and hit fuel cut. Im happy with the performance improvement (13.58 1/4 mile) but if i did it again i would save up for an electronic boost controller because it adjusts itself and holds the right boost, and is easily adjustable from the drivers compartment.

 

your car goes "vroooooom vrooooooommmmm then it sorta pops, you lose power and your CEL comes on.
I dont know about the other question, i was sorta wondering the same thing

 

Yes you can. With just a MBC though with a dyno tune you wont see/feel much difference. Youll need to free up exhaust and other mods to get the benefit of a dyno tune. I finished all my mods so now its time to tune the chip. My mods are:

MBC set to 15.5
Greddy Evo Catback
Vishnu 321 Uppipe
Samco IC hoses
Intake silencer removed

I talked to vishnu and I dont have to do a reflash. I guess thats just if you have a whole bunch of mods. For me they have preset maps they will just install and fine tune.

You'll know when you hit fuel cut. IIRC it is set at 17 psi. Basically you just stop going. It feels like when you let off the gas quickly and the CEL comes on. Ive done it once on a cold morning. Thats when I set my boost from 16 to 15.5. But within a day or so if normal driving and no more overboosting the CEL will clear itself. At least mine has.

 

If you are getting the gauge from subaru (mine is) it is in Mpa. So basically .05 = 7.35 psi and .1 = 14.7 psi or 1 atmosphere. You want the needle to peak at ( in 5th gear on a 5mt) between .1 and .11. no more then .11 max.

Im not sure what they change on a dyno tune. I was told they have new maps (fuel settings etc) to make the best power for your mods. For Example, If you free up your exhaust the existing maps wont really know what to do with it. You will get some performance increase, but just what the stock map will allow. You put in a new map with what to do with the new increase in flow and you will definitley get more power/torque.

I will be going to vishnu in about a month. I will let you know when I am going. If you are ready to remap yours, you could meet me up there. The price is (last time i talked to them)
$90 to use the dyno
$200 per hour of tuning

said it usually takes about an hour. so figure about $300 to $400

If you are going to use an MBC, be sure to tell them to install the map to fix the PT/FB issue.

Never mind about meeting. I had a brain fart and thought I was in my regional forum. Oops

 

Im not to familiar with the profec b so Icant help you there. But we are planning another meet in about a month. Keep an eye out the the bay area forums and i will let you know. Maybe someone else familiar with the profec b can jump in and help.