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Exhaust Concerns

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Location
Brooklyn
#1
Installed my Thermal R & D exhaust about a month ago. I have been noticing occasionally i will hear a dragging metal sound as if the exhaust was dragging across the floor. It won’t last more than a few seconds and then it is gone once I accelerate. I installed it myself and made sure everything was tightened and there were no leaks. Took a peak under the car and it seems the mid sections of the exhaust hangs lower than the rest but definitely not low enough to contact the ground. It is the part after the resonator but before the “s” bend. Any ideas what it could be ?

Also- second question- when i decelerate the car is much louder and almost sounds like it’s got some crackles. Not necessarily a bad thing but it borders on sounding like something is wrong. There’s also some drone even if my foot is barely on the accelerator anytime no matter the RPMs.
For example, sixth gear at 1800 RPMs on the highway and it is loud in the car if I keep my foot at a constant spot on the gas.

Things to consider- Cobb stage one tune, symposer delete, stock exhaust hangers.

Thanks for any help you can give me !


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green_henry

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#2
Definitely replace the hangers. My exhaust is stock and I noticed odd noises every once in a while -- Mountune hangers fixed that issue. Probably won't resolve your issues, but it would be a good first step.
 


Dpro

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#3
Interesting I get off mine and it goes quite. Sixth gear at 1800 rpm? Lol how fast do you go on the hwy thats gotta be lugging the hell out of it, can’t imagine its more than 45-50 at which point I would not even be in 6th.
 


TyphoonFiST

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#4
Definitely replace the hangers. My exhaust is stock and I noticed odd noises every once in a while -- Mountune hangers fixed that issue. Probably won't resolve your issues, but it would be a good first step.
Are the mountune hangers any longer then the stock ones? I have the Thermal also...I have the Dizzytune with loud crackles and its perfect... it's a great exhaust...only loud when you get on it...I also have a GEN2 GTX2860...maybe that plays part....the BAE likes it also...says it reminds her of an airplane taking off...nice and steady then wham it gets louder and away you go!


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OP
S
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Thread Starter #5
My thoughts were to swap the hangers first too but before doing that wanted to get everyone’s opinions. I’ll probably start there.

Roughly like 55mph cruisin, if I need to accelerate I’ll just downshift this way i don’t lug the engine too much. Is that a bad idea ? I’ve only recently gotten into driving manuals (less than a year)

Maybe something is wrong with the exhaust? Bc it’s loud and sounds great after like 3k but before that it’s kind of annoying. I wish i had a lift or someone close by who can help me smh




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DangerMouse

Senior Member
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Rockford
#6
Sounds like a leak. My thermal is very tame, no drone, even after mountune downpipe install. I do get some nice but les on decel. After a few weeks the burbles would get louder and I would get drone. The midpipe was slipping out of the clamp.

Did you replace the gasket on the downpipe side? Also it shouldn't really be hanging down unless the pipe has slipped out of the clamp.

Also based on advice from some here, tighten the clamps as tight as you can get them. I was using an impact and thought that was good enough. I used a 24" ratchet bar and got quite a few more turns on them.

Good luck.
 


TyphoonFiST

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#8
They are the same size, just stiffer. The stock hanger closest to the front of the car is really flexible. I got the Mountune set because it had all 4 hangers; some other sets only come with 3.
I see....how close does everyone's Thermal sit to the bottom of the bumper? I think I might do some thermodynamic readings just to see as it does concern me alittle....as the Tips have already branded me once.


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OP
S
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Location
Brooklyn
Thread Starter #9
Sounds like a leak. My thermal is very tame, no drone, even after mountune downpipe install. I do get some nice but les on decel. After a few weeks the burbles would get louder and I would get drone. The midpipe was slipping out of the clamp.

Did you replace the gasket on the downpipe side? Also it shouldn't really be hanging down unless the pipe has slipped out of the clamp.

Also based on advice from some here, tighten the clamps as tight as you can get them. I was using an impact and thought that was good enough. I used a 24" ratchet bar and got quite a few more turns on them.

Good luck.
Thanks I appreciate the advice. I’m going to get it back up on some jack stands and get a long ratchet to tighten everything up.

I changed the gasket and put a brand new one in to be safe. I feel like the midpipe may have slipped since the clamp is only a circle ring and not one of the heavier duty ones.

Anyone have torque specs for the bolts ?


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OP
S
Messages
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41
Location
Brooklyn
Thread Starter #10
I see....how close does everyone's Thermal sit to the bottom of the bumper? I think I might do some thermodynamic readings just to see as it does concern me alittle....as the Tips have already branded me once.


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Mine has about a half inch of play by the bottom of the bumper. Since it’s the crappy stock hangers it’s pretty dam flexible and able to move around with just my hand.


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Messages
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Location
Naples
#11
Something does not sound right. Definitely replace the gasket at the down pipe and replace the hangers too. Make sure the pipe connecting joints are tight and not touching the car anywhere. I suspect a loose joint or pipes touching the car somewhere. The crackle and pop sounds are normal.

I installed my MBRP CAT back at home. It came with new hangers and a gasket at the down pipe. It installed super easy although it was a tight fit with the 3" pipe. I had to snug the clamps and adjust it for best fit and even clearance in the spaces allowed underneath the car. The sound is so perfect for me- I love it so much. It cracks and pops on decal and sometimes in between shifts and I just love it. No problems at all.
 


OP
S
Messages
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Location
Brooklyn
Thread Starter #12
Something does not sound right. Definitely replace the gasket at the down pipe and replace the hangers too. Make sure the pipe connecting joints are tight and not touching the car anywhere. I suspect a loose joint or pipes touching the car somewhere. The crackle and pop sounds are normal.

I installed my MBRP CAT back at home. It came with new hangers and a gasket at the down pipe. It installed super easy although it was a tight fit with the 3" pipe. I had to snug the clamps and adjust it for best fit and even clearance in the spaces allowed underneath the car. The sound is so perfect for me- I love it so much. It cracks and pops on decal and sometimes in between shifts and I just love it. No problems at all.
Thanks man. I’ll be checking it all before I get the first snow of the year and makes things impossible. Appreciate the feedback !


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TyphoonFiST

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#13
Mine has about a half inch of play by the bottom of the bumper. Since it’s the crappy stock hangers it’s pretty dam flexible and able to move around with just my hand.


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I just went out and put my foot on my Thermal Tips....pushed down with my size 10 and wham it's now lower...the isolator must have got hung up somehow...yay!



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Last edited:

Jerickson88

Active member
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Rock Creek
#16
Thanks I appreciate the advice. I’m going to get it back up on some jack stands and get a long ratchet to tighten everything up.

I changed the gasket and put a brand new one in to be safe. I feel like the midpipe may have slipped since the clamp is only a circle ring and not one of the heavier duty ones.

Anyone have torque specs for the bolts ?


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On the past on a bolt on exhaust system, I’d put on and clamp it down and then run to exhaust shop and let the guy throw a small stitch on all of the slip overs. That way if I ever needed it off, it was just a grinder and flap wheel. I’m not talking about a full on bead around the joint, just a tick to tie it together Incase a clamp let loose one day.
 


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