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Discussion Starter #1
Hi, I'm new here and have a dumb question. I have a Turboxs MBC, it's set to 15psi. but when it's cold out in the morning I'll hit 16psi in 3rd and 4th gear and it will go back to 15psi when it's warmer out. Why? Also, why does my WRX make less than 15psi in 1st and 2nd gear?
Thanks for your answer(s) :)
 

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OK, I'll chime in to second this question. Who is running MBCs in the mountains? I guess my real question is: is it feasible to run an MBC on a car that will be routinely driven (FAST!) from 6000ft to 10,000+ft and back again? Or will I have to pull over every couple thousand feet and readjust the thing? (Or fiddle with an in-car adjuster every 1000 ft). When trying to run Left Hand from the Bus Stop to the Chief in under 14 minutes, I don't really have time for a pit-stop!

Oh, to answer PWRTRPs second question: you must have an MBC that doesn't totally cut out the FBC (Factory BC). Subaru programs the computer for less boost in 1st and 2nd to make life easier for the drivetrain. A lot of people set up their MBC to override this - but I'm not sure that's such a great idea. Subaru engineers do know a thing or two about what makes the Rex tick!

C
 

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On colder mornings, air is more dense and your boost controller screw needs to be adjusted if you don't want to overboost. That is why I have an EBC, it does a better job up here and can change it in the cockpit (however there is a considerable price difference for this luxury).

You probably won't get much higher than 15.5 psi here on the stock turbo because of our altitude. You could open your exhaust up some and that will help you a little.
 

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Discussion Starter #5
I live at around 3,500 ft and usually stay close to that altitude. But will I need to turn down the boost when I go boarding up at the pass? (8,500 ft)
 
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