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Discussion Starter · #1 ·
Let me start off by saying I'm pretty careful about noticing boost leaks. I don't think I had any before this install.

I was running the COBB intercooler and COBB hot charge pipe.

I just replaced them with the large 5.5" cp-e intercooler and hot charge pipe.

First thing I noticed when driving today is my boost jumped from 25.6 to 27! Is there any way the new intercooler can cause this - more efficient flow/less pressure drop? Or must it be that I had a boost leak and didn't know it?

And - do I need to re-tune now that I'm running 1.4 psi higher boost than when I logged and tuned with my tuner?
 

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If the Cobb hotside charge pipe was installed before your CPE RMM, I could see the pipe getting a small boost leak over time due to excessive movement. Maybe that's it?
 

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There's a post somewhere here that the Cobb hotside pipe developed a hairline crack at the weld where the mount bracket is welded on. Might want to check that out before you sell it! Also consider that if there was a leak, your turbo will have spinning noticeably faster to compensate for the leak.

Typically my experience is that boost goes down with a better intercooler, as our programming is load, not boost based. So a colder charge means we reach maximum programmed output at a lower boost level.

Hope that helps,
Mark
 

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Discussion Starter · #4 ·
There's a post somewhere here that the Cobb hotside pipe developed a hairline crack at the weld where the mount bracket is welded on. Might want to check that out before you sell it! Also consider that if there was a leak, your turbo will have spinning noticeably faster to compensate for the leak.

Typically my experience is that boost goes down with a better intercooler, as our programming is load, not boost based. So a colder charge means we reach maximum programmed output at a lower boost level.

Hope that helps,
Mark
That's really interesting then. I'm starting a fresh tune cycle with Alex this week, so it will be interesting to get his feedback after sending new logs with these changes vs my previous tune/FMIC related logs.
 
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