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Old 01-01-2018, 06:25 PM   #1
buds115
 
Drives: Camaro 1SS 2014
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NoWeeds Diverters Backfire sounding noise HELP

I installed noweed diverters the other day. I have a LS3 2014 Camaro SS. I have a K&N cold air intake, NPP, and Solo high flow cats. I wired a switch that allows me to keep the NPP closed to be “quiet” when I want it. With the diverters closed and the NPP valve closed and at about 20 MPH in 2nd gear and sometimes in 3rd gear I hear popping coming from what sounds like the diverters. This is while accelerating so it is not the deceleration pop due to DFCO. The temperature where I am is currently 10 degrees F. At first I thought it was a leak around a clamp so I tightened them all with an impact gun and no luck. Also thought it might be a rattle so I drove on a rough road... no noise. Can anyone help me diagnose this noise?
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Old 01-02-2018, 06:52 PM   #2
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Because you have HFC's, I'm assuming that you have had your car tuned?
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Old 01-03-2018, 01:03 AM   #3
buds115
 
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Car isn’t tuned. It actually seems as if the exhaust wasn’t leaking and the pipes were hitting one of the trans cross member bolts. I have 4 new clamps on order and should be able to take another go at this on Thursday. Wish me luck
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Old 01-03-2018, 09:36 AM   #4
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It would make sense that under the load of the car, or engine "chugging" that the exhaust could be shifting more and be hitting somewhere. Perhaps a go pro under the car? Wind noise might cancel it out, but it would help us.

Maybe adjust the diverters pretty far away as a test if you think the noise is in that area. Will effect ground clearance for the test. Also remove tunnel brace for the test.

Hard to think its a leak, as it should get worse as exhaust pressures increase/higher rpm.

Hopefully it is just a small mounting tweak needed.

Good Luck and let us know.
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Old 01-03-2018, 10:53 AM   #5
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Quote:
Originally Posted by buds115 View Post
I installed noweed diverters the other day. I have a LS3 2014 Camaro SS. I have a K&N cold air intake, NPP, and Solo high flow cats. I wired a switch that allows me to keep the NPP closed to be “quiet” when I want it. With the diverters closed and the NPP valve closed and at about 20 MPH in 2nd gear and sometimes in 3rd gear I hear popping coming from what sounds like the diverters. This is while accelerating so it is not the deceleration pop due to DFCO. The temperature where I am is currently 10 degrees F. At first I thought it was a leak around a clamp so I tightened them all with an impact gun and no luck. Also thought it might be a rattle so I drove on a rough road... no noise. Can anyone help me diagnose this noise?
What RPMs does it happen at? Could be the NPP in closed mode when it should be open is causing too much back pressure
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Old 01-03-2018, 12:42 PM   #6
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Air leaks will cause the unburnt gas to detonate causing popping. Adding cats with no tune also makes the car run richer even though that's counterintuitive.
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Old 01-03-2018, 11:05 PM   #7
buds115
 
Drives: Camaro 1SS 2014
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Quote:
Originally Posted by QUICRNU View Post
It would make sense that under the load of the car, or engine "chugging" that the exhaust could be shifting more and be hitting somewhere. Perhaps a go pro under the car? Wind noise might cancel it out, but it would help us.

Maybe adjust the diverters pretty far away as a test if you think the noise is in that area. Will effect ground clearance for the test. Also remove tunnel brace for the test.

Hard to think its a leak, as it should get worse as exhaust pressures increase/higher rpm.

Hopefully it is just a small mounting tweak needed.

Good Luck and let us know.
I ordered some new clamps. Also bought some washers to drop the tunnel brace down about an inch. Clamps should come tomorrow but I’m unsure due to storm hitting the northeast. I’ll keep this post updated.
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Old 01-08-2018, 03:20 PM   #8
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New clamps in. Tunnel brace lowered. Diverters repositioned. Drove it around for a little bit and so far so good. No noise at all. Thank you all for your help!
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Old 01-13-2018, 12:28 AM   #9
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If you have 3” dia exhaust then it was your tunnel brace smacking the exhaust pipes. BMR and Elite Engineering make a brace for larger aftermarket exhaust.


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Old 01-13-2018, 08:59 AM   #10
QUICRNU

 
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Quote:
Originally Posted by buds115 View Post
New clamps in. Tunnel brace lowered. Diverters repositioned. Drove it around for a little bit and so far so good. No noise at all. Thank you all for your help!
Glad to hear it!

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