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Discussion Starter #1 (Edited)
Hi there,

I have my car for about 2 months now and I feel like the engine had lost some power but I'm not really sure because now I'm driving more confident than when I got it. Is it normal when you are on the highway at 50mph on 5th gear (manual car) and accelerate hard, I can hear something like a blow off valve all the way (I have all stock engine) and then when jump from the pedal I hear a blow off (repeat stock engine). I feel like the turbo system have a leak and is losing pressure, but the gauge reads more than 15psi so this is why I'm not 100% sure. I just remember the car wasn't doing it when I bought it... Any thoughts?

PD: Is a bit difficult to explain form me because I'm spanish and my mechanical english is not very good now hehe
 

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I think what a few of us will tell you is what are you doing in 5th gear at 50mph.
As far as I am concern you are loading the engine at that speed on 5th gear and then accelerating hard. Down shift please..
 

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Discussion Starter #3
I know LatinVenom, but that's just an example of what is happening. Even from 2nd to 3th gear I can hear it. I think when the turbo is making the work and making pressure, the system is losing some of the pressure somewhere but as my gauge reads normal values maybe is my imagination..
 

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Discussion Starter #4
Definitely after driving it yesterday I'm sure it lost some power since that. Which is the normal turbo pressure for stock? mine is going until 15psi but on hard acceleration I can hear like the pressure is going somewhere else, not to the engine
 

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If I recall correctly, 14-15 pounds of initial boost is fairly normal for a stock GXP/Redline. Some have reported up to 17, tho I never got even a quick blip that high with my redline. Now, I'm hitting 25.
 

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There is no set value for what peak PSI you should observe. It varies greatly depending on altitude, ambient air pressure, and efficiency of your particular turbo.

If you think you are hearing a pressure leak:

1. Check all clamps, especially the throttle body clamp. (Throttle Body Clamp is a piece of crap, replace with a good quality T-Clamp).

2. If running factory Intercooler, check it for a split on the passenger side end tank seam. It will split right along the end tank seam weld. It is very difficult to observe unless you pull the plastic shroud off the bottom of the car, so that you can look up in there.

3. Also: You can pressure test the Intercooler and pipes, while still in the car. There is a how to posted on the forum somewhere, or you can take it to GM and have them pressure test it.
 

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Not sure if this applies to Turbo versions but in my humble plain vanilla Solstice the Catalytic converter became clogged up around 40K miles and my performance dropped by 25%. After replacing converter (free) the car was like new.
 

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If you are having significant boost leakage you would be getting CEL codes. 15 to 17 pounds of boost at sea level is normal for a factory tune.

The 2.0 motor does NOT respond well to loading it up at low RPMs. My rule of thumb is to keep it above 2500 RPMs when under any kind of load. Cruising at low Ms is not a good thing.

Are you using 93or higher octain fuel?
 

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Discussion Starter #9
Thanks you guys for your replies. Looking over youtube this morning while working :yesnod: I found this video which is almost the sound than I'm hearing when accelerate.
I know that one is supercharged instead and the solution there doesn't help, but is that sound.

I also talked to a mechanic friend of mine and told me to check the line than goes from the turbo to the filter, because most of the times this is the cause of that problem. Curiously maybe the max PSI maybe is dropped like 2 or 3 PSI but the power significantly went down.

I'm going to check all of this things over the weekend while doing other mods.
 

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Discussion Starter #10
I finally found the issue. It was what I expected, the intercooler connections were losing the pressure so I'm going to replace probably the connectors to Silicon and T-Bolts and that will solve the problem. Ordering soon, for the moment the once I fixed are working now but expecting to have the same issue soon...
 
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