Drone/pressure with new Thermal R&D exhaust under load only

[rexnebula]

I recently purchased the Whoosh-spec Thermal R&D exhaust and had it installed earlier this week by a local exhaust shop. Under full throttle acceleration from ~3200-3800 RPMs there's often a very loud drone or full pressure feeling in the cabin. From 4k-6k it's great and below 3k it sounds nice. Cruising along in that same 3200-3800 power band doesn't have a drone or pressure feeling either. I purchased the Thermal due to all the reports here of it not droning, so my assumption is that something went wrong with the install. I'm assuming something isn't tight under there, I have some leak or a piece of the exhaust may be hitting a part of the frame. Does anyone else have other ideas of what to look for when I put her up on jack stands this weekend to investigate? Car has stock downpipe right now, dizzy tune, intake work and upgraded rear motor mount. I had the shop install the Whoosh exhaust hangers while doing the exhaust install.

 

[M-Sport fan]

Sometimes the installers do not get the Thermal mid brace (that stainless steel {or alloy?} \__/ shaped piece) hanger correctly mounted.

The instructions must be followed explicitly for that hanger mount.

 

[foodtruck]

Try using the stock hangers and see if it makes it tolerable. I recall they made a big difference when tried putting on an aftermarket exhaust. IIRC the one that goes right under the driver's seat is thinner than others, for a good reason.

Unfortunately, as I found out myself, the "mild" level of NVH that's tolerable to some isn't to others. Hold on to your stock exhaust; this way you'll have a backup plan if you end up throwing in the towel.

 

[lemonjs]

I had the same issue at the same RPM - for me it was the downpipe making contact with a bracket by the steering rack.

Although you haven’t changed the downpipe, the new exhaust may have pushed the downpipe backwards. Worth checking!

 

[rexnebula]

Sometimes the installers do not get the Thermal mid brace (that stainless steel {or alloy?} \__/ shaped piece) hanger correctly mounted.

The instructions must be followed explicitly for that hanger mount.

Ooh this is a good tip, thank you! I didn't get any installation instructions with my kit and don't see any on Thermal R&D's web site. I did find this other thread here - is this explaining what you're talking about regarding the mid-brace and how the hanger should be mounted?

 

[rexnebula]

Try using the stock hangers and see if it makes it tolerable. I recall they made a big difference when tried putting on an aftermarket exhaust. IIRC the one that goes right under the driver's seat is thinner than others, for a good reason.

Good suggestion, I'll give that a shot if some of the other suggestions don't fix it.

Unfortunately, as I found out myself, the "mild" level of NVH that's tolerable to some isn't to others. Hold on to your stock exhaust; this way you'll have a backup plan if you end up throwing in the towel.

Yeah, you're right what may be okay for others might not be for me. However I do think it is unusual due to how loud and how much "pressure" there is inside the cabin (I don't know how else to describe the sensation). so there must be something wrong. Unfortunately the shop dumped my stock exhaust because I didn't have any place to store it at my house and it was easier to have them dispose of it.

 

[rexnebula]

I had the same issue at the same RPM - for me it was the downpipe making contact with a bracket by the steering rack.

Although you haven’t changed the downpipe, the new exhaust may have pushed the downpipe backwards. Worth checking!

Hmmm yeah interesting. I'll look for that when I get it lifted later this weekend.

Thanks everyone for the suggestions so far - gives me hope to find the source of the problem. I'll report back when I get it fixed!

 

[M-Sport fan]

Ooh this is a good tip, thank you! I didn't get any installation instructions with my kit and don't see any on Thermal R&D's web site. I did find this other thread here - is this explaining what you're talking about regarding the mid-brace and how the hanger should be mounted?

Yes, EXACTLY!

 

[Dpro]

also some thing to remember with The Thermal exhaust is it’s a slip fit with clamp,. If they clamps are not tightened properly you will have it working loose and getting louder. I usually checked my clamps around every oil change to make sure they were tight. What Msport said above it’s true the primary area that tends to work itself loose is right after the mid brace. Once it gets loose the front section tends to drop down and sometimes can rattle on the mid brace. Ask me how I know😂 Done right you will have tone but not drone .

 

[Ludeem1]

I had to adjust mine like 10 times to get it right, I was getting a very bad vibration that got worse and worse especially after a pull the exhaust would shift. It would even slip off the clamp at the Downpipe adapter no matter how tight I made that clamp. I ended up loosened everything and adjusted it and finally I got it right and it’s been solid for a year and counting.