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Discussion Starter · #1 ·
First off I would like to start by saying everyone on this forum has helped me out big time. Everyone has always been quick to post and PM me any info that could help me out with my questions and I just wanna say thanks.

Now this weekend I tossed in a GFB BOV (100% atmosphere) and the AEM short ram and a boost gauge. The JoeP didn't go in because we aren't sure if we are getting the proper readings from the guage. When we first started it it read 20 on the vacuum side of the guage. The only time it made over to the PSI side of the guage is when we accelerated hard. It made it to about 13PSI in third and maybe fourth but we had to really get on it to make that happen. But when we are driving regular it rarely goes past 5 PSI is this correct?

Thank you for any help that can be offered I'm very anxious to get the JoeP on but I don't wanna run the car lean if the gauge isn't correct.
 

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i believe the stock WRX boosts about 13.5 in 3rd gear (correct me if im wrong) so ~13psi is what you should be seeing in 3rd gear since i think the ECU limits the boost in 1st and 2nd gear. from what you are observing it seems to be working ok. I assume you have an autometer gauge or similar?

-c
 

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you are right on par with most ~stock wrx's. at idle almost all of us are between (or should be between) 17 and 20 in/Hg in vacuum. without A/C i'm at 18 in/Hg vacuum at idle. you are also correct about building boost. it is somewhat difficult to make higher boost (above 10 psi). you have to really be on the throttle. the stock ECU is constantly monitoring your throttle position, and will only give you full boost when you have it smashed. watch your gauge, if you are at ~75% throttle, you'll get around 8-10psi. your ECU is telling the stock boost control solenoid to close up a little tighter (because you aren't at full throttle) to make the wastegate open up a little more. as soon as you smash it the ECU tells the stock solenoid to open up (this guy 'really' wants to go fast), bleeding the pressure away from the wastegate, and thus raising the boost level. of course, this all changes with the addition of the mbc.

hope this helps.
 

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Discussion Starter · #4 ·
HA

See what I mean you guys are the best! Ok so it is normal to read right around 20 on the vacuum side? And then under hard accelration it sometimes jumps up to about 12-13. But it never stays there it spikes and then bounces between 10-15 and then we shift. Also I understand now exactly how the JoeP goes on. Basically it splices between the top of the turbo and the wastegate correct? But when we put it on do we turn the boost all the way down to start with? And then work up?

And yes it is a really cool white faced gauge from Summit Racing
Mechanical not digital
 

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Discussion Starter · #5 ·
one more thing the car threw a CEL (check engine light) after installing the Gauge, BOV, and short ram intake anyone have any suggestions?

Thank you
 

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i'm pretty sure that would be the short ram. some people were getting them when installing those. it might be the combination of the bov and short ram, especially if you're venting 100%.

yes, the joe p will go in place of the factory line that goes from the turbo nipple to the wastegate. you just plug the line that is Teeing into that (the line going to the factory boost solenoid under that black cover). you want to start with the joe p screwed all the way out, and slowly turn it in. for a while you'll be hitting right around 8psi, probably even after several turns in. what's happening is the spring pressure is not greater than 8psi, so all pressure is being passed to the wastegate, which begins to open at 8psi. look at it this way, if you just had a line from the turbo nipple to the wastegate, nothing in-line (like an mbc), you'll be getting solid 8psi. in that case you are just using the wastegate as the boost controller.
 
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