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2G Boost issue, help.

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Ohhchhittt

Proven Member
115
2
Oct 20, 2014
Naples, Florida
yes I searched, LOL

So I was messing around with my car cause something was not right. I lost 2 lbs of boost some where.
Thought it may be a leak. So I tested it. Seems good. Holds lbs with a really really slow let off.
I tried diff things removing hoses and re fitting them. I bypassed the BCS and ran a hose from the turbo to the WG. Ran good held boost this time around 8-9 psi. So I thought it may be the bcs. I installed the T on the turbo/WG hose and ran the other end of the T to the intake nipple. WOW. BOOST LIKE A ..... Hit 18-19-20- think it even hit fuel cut off. At 20. When I took off it would spool up to 18-20 and drop to about 14 and hold. But if I was in 5th and stepped on it I wouold hit 20 and it felt like fuel cut off. Put the bcs back on and steady 10-11. sorry if this post is all over the place. So the issue I had seemed to go away when I put the BCS back on. But the ? I have. By bypassing the BCS the way I did why was my boost all over the place. I have read you can bypass it.

Thanks for the help guys.
 
Seems to me that by removing the BCS, you no longer have a controlled boost output, so therefore you're going to see it fluctuate they way it would without a controller. So having the BCS keeps boost psi smooth and steady, no BCS shows natural erratic boost pressure. Just my thought on the topic.
 
I agree the bcs should regulate the boost so it's not all crazy, I thought there was a restriction somewhere that you could remove to increase you boost a little while still using the bcs.
 
That's what I was thinking. But I wanted to make sure. I did remove the insert on the BCS already. Guess my next step is to get a boost controller
 
Several of the above posts aren't very clear to me. BCS doesn't control boost..it's a designed in bleed from the line going to the wastegate. The orifice is very small so you get a few lbs more than the wastegate spring. If the bcs gets shut down from knock etc you see spring pressure for boost. When the op installed a T with no BCS he introduced a large bleed and that's why he got a lot of boost. What he did is not what people mean when they said they bypassed the bcs. Bypassing the bcs just means you took it out of the loop and are either running straight spring pressure or some method of boost controller etc.
 
Ok so I wanted to start over. I put every thing back to stock and I do have the insert removed from the BCS. I originally war holding strong at 12lbs. Now when I read it its only holding a 10lb with a little drop off to about 9lbs then holds. I did a boost leak test and it seems to be good. I filled it up to 12lbs and it holds with the BLT with a very slow drop. What would have changed to loose that 2-3lbs you think
 
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