weykool

I just purchased a 2006, ZO6 that has Akrapovic cat back exhaust on it. The inside cabin noise is very loud and makes it almost too hard to carry on a conversation in the car when traveling down the road. I have read a few things about this cabin noise and I am asking for some solid advice. There are numerous sound deadening products out there and I am looking to see if anyone can actually give me some first hand experience and which is the best way to eliminate this road noise. I was thinking perhaps Dynamat, but wanted to see if anyone had actually tried this or something different and had any success.
All inputs here are welcomed. I love my car but need to quiet down the road noise somehow.
Thanks,
G

DaveVette91

These engines drone bad.

Sell that akro and get yourself a Corsa, the least droniest of the bunch!

MTPZ06

Do you know if the bimodal exhaust valves are functioning as they should, or are they held open at all times?

weykool

Yes they are, in fact I installed a wild to mild system so I am positive they are working properly.

Unreal

Dynamat and products like that can help, but they just turn the volume down from say 10 to 8-9. They aren't miracle workers. If you really can't stand what you have now, you need new mufflers as you can spend a ton adding weight/cost to the car and it will take the edge off, but may not make you happy.

MTPZ06

Do you have long tube headers? I know Akra has some drone, but it sounds like your setup is louder than most?

weykool

I apologize here I should have provided more information in my post. I am running Cat back Akrapovic exhaust with stock manifolds, Bi Modal exhaust is functioning as it should. I am also running ZR1 rims, front and back with Michelin tires. I know some of this noise is from the exhaust, but I notice changes in the road make the noise softer or louder so I am thinking a good portion of my noise is from the road.
I am researching sound deadening materials to quiet the noise. I am not changing my exhaust as I love the sound. I am searching for advice here on the best way to quiet my noise with some type of sound deadening material and before I spend the money I would like someone with experience to let me know what they know to work and what not.
Looks by my research that FatMat seems to be the best buy for the money.
Any help is appreciated.

MTPZ06

Exotic Vettes sell a complete kit that insulates against heat and sound. I thought about combining that kit with the Block It drop in kit, but wanted to see about installing both under the carpet at the same time. Throw a nice Lloyds cargo mat on top, and I figure that would be Max effort for me.

I know many are happy with just the Block It drop in kit that goes behind the seats and cargo area, as that kills a lot of the road noise coming in from the rear wheel wells. You may also want to look for threads in the Audio/Electronics section, as I know they discuss this same topic in there as well.

Michael_D

I'll be applying deadening material over the next few weeks. It's a pretty complicated topic, and butyl material is only one component of the combination. Too much for a smart phone response.

dmuellenberg

I switched from the OEM GY run-flats to non run-flats and that made a huge difference for me as far as road noise is concerned. I can't attest to Michelins but if they are run-flats I'm thinking switching to non run-flats would help with the road noise. Of course it depends on how you drive your car determines what tire you should use. But if you mainly use it for a street car (non track) then I would recommend non run-flat tires.

Les

I have the same exact exhaust set up as you. Here's a link to what I did about it. It didn't eliminate the drone but it sure made it a lot better. The acoustic tiles combined with the 2 part mat not only helped a bunch with the drone, they also cut back on road noise too. Hit me up if you have any questions after reading through the write up.
https://www.corvetteforum.com/forums...materials.html

TKO Performance

Yes and thank you. We received a ton of positive feedback on the Blockit "Drop In" mats. Takes 60 seconds to install. Great for tire & road noise and for some exhaust.



Check it out here:
http://store.tkoperformance.com/200520131.html



Drone is another animal. Its a frequency that is hard to eliminate. The Blockit will take a bite out of it. But its not going to turn your car into a Cadillac. To get it closer you will have to remove the carpet which requires a little more work and lay down a sound deadener/damping product.
We now have DeadMats which is a lightweight sound damping product. Performance to weight ratio is amazing. Your able to stack these if you need more in a certain area.

Watch it eliminate noise/vibration here:










Learn more here:
http://store.tkoperformance.com/200520131.html

Any questions, just call 1800 778 9898

weykool

Thanks! That's exactly what I was looking for. Can you tell me about how long the total removal of carpet and install of everything took you? Just curious. And I believe you included all the links so I can purchase all of the materials so thanks again. I expect to get into this in the next month or so.
G

TKO Performance

Your welcome.
It sounded like you might need both. But I would try one first. See how that goes.
When you have time, call us and we can discuss your Sound deadening solutions

LMBTom

Get yourself some sound-proofing foam/insulation, not sound deadener. If you want to be cheap like me, you can get some hood insulation (stick-on foam) and cover up the entire rear area under the carpet. You'll also want some directly behind the seats.

hungryhorace

There are several issues at play, tyre size, lack of sound proofing for weight and the design of the exhaust/muffler tip and the rear bumper (not sure what its called in America) causing resonance.

The first easy change is to add sound proofing, either to the whole of the car (as I am slowly doing) or to the trunk.

Here is a before and after video, save your time and money and fit the right stuff first time.



This has made a big difference but its still not luxury sedan quiet, it never will be.

Next you need to overcome the resonance/booming caused in the rear bumper (the big flexible plastic bit at the back of the car with the lights). You could add deadening material but it will probably come off eventually. The biggest way to reduce boom is to alter the length of the muffler tips. Its not as good as a resonance tube but by simply extending the length of the tips by an inch or so can drastically reduce cabin boom.

The boom tends to occur around the 1500 to 2000 rpm range, I find cruising in 5th the most comfortable.

Total time to fit the sound deadening to the rear trunk is about 2 hours and will shave a good few dB from the cabin. I'm running a full custom system and the work I did made it manageable to go to Poland and back, te return trip in a single day ending with no hearing problems. Before we did this, the ears would be sore after an hour or so.

hungryhorace

You need the deadening material to remove the resonance, carpet/foam will not do this. It is the resonance that causes the booming, the foam/carpet will however help to reduce overall noise but its like using an ice cube to put out a fire. Deadening first, then foam/carpet after.

weykool

Thank you so much for the info and the video! It really helps to see a before and after video. I think I have a plan now and I just need to get materials ordered and installed. Do you have anything on how to remove the rear carpet from the car?
Thanks again!
G

hungryhorace

I'd forgotten about the sound deadening matt as posted above, that would make a great addition along with the sound deadening.

You will be adding weight, if you do the full car its quite a bit but it improves the experience so much so its worth it. My next step if I keep the car is to do the same to the front cabin, doors, roof and behind the seats.

Michael_D

Took me about four hours from the moment I gathered motivation to do it this past weekend. That includes removing the speakers, Bose HU and amp, and basically getting the car ready for running wires and starting the deadening process. Another four hours moving the On-star module and modifying the pass seat electrical connector for a power seat mod in the future.

I'll be doing this with three or four layers. 1) butyl deadening strategically placed, along with butyl rope in the doors 2) an adhesive backed high-density foam over that to act as a decoupler 3) Mass Loaded Vinal on the deck, and possibly on the doors if I can figure out how to hang it.

I'm trying to keep total weight increase, under 75 pounds.