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09-22-2011, 02:32 AM | #1 |
Bashar
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Exhaust tone change
So I've noticed while driving in traffic that the exhaust tone seems to change at certain times while I'm driving. I notice that the tone gets sort of deeper and louder, as if something like a valve has opened up, for about 30 seconds at a time then its back to normal. My mods are muffler delete, DCI, and JB4 (map5), however this happened before the JB4 install also.
So I was just curious to see if anyone knows what this is and if it can be induced |
09-22-2011, 07:25 AM | #2 |
Lieutenant
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I am FBO with Cobb Stage 1 and mine does that as well. From what I understand, it is the wastegate opening/closing. I believe it is more noticable with an exhaust on.
I really don't know why the wastegate would be cycling under a cruising condition? Can someone learn me? I was really hoping I could someday get a definitive answer on this issue. |
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09-22-2011, 10:02 AM | #3 |
Private First Class
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Yup, I get the same "symptom" with a Dinan Stage 2 ECU and Berk sport exhaust. It happens consistently when I'm cruising and the throttle is held in the same position... after about 10 seconds the exhaust note changes to be lower, deeper and louder. It goes away if I add more throttle, or if I back off for a few seconds.
I never knew what caused it, but I considered it normal operation because it is so consistent and doesn't affect driveability.
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09-22-2011, 11:04 AM | #4 |
Banned
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Im pretty sure its VANOS changing the timing due to an increase in load but constant throttle/rpm. It only happens when im cruising at a steady rpm and then start to pull a hill.
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09-22-2011, 07:57 PM | #5 |
Bashar
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Yeah, it does happen while cruising also. It doesn't really go away with adding throttle or letting off. I do like the pops and crackles that occur from the exhaust when letting off though lol.
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09-23-2011, 12:27 PM | #6 | |
Captain
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Quote:
Yup! When I hear the exhaust get deeper/louder, I always make sure to let off the throttle to hear the burble and pop. |
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09-24-2011, 04:00 PM | #7 |
Captain
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I notice this as well. Seems much deeper at 50% throttle, once i floor it the noise isn't as loud..
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