[crfine88]

#25

After adding the ESS kit my RPI exhaust became even louder. As a result, the drone at freeway speeds became unbearable.

I decided dampen the trunk. I picked up some off brand material from Fry’s Electronics. The product is very similar to Dynamat, but at half the price. This was in no way a performance mod because I was adding weight to the car. I was conscious of this fact. I figured that it would not hurt add a little weight over the rear wheels since I had saved so much when I added the RPI’s.

- I saved 29lbs with the RPI GT exhaust.
- I added 14lbs of dampening material.
- In the end still 15lbs lighter and the drone was dramatically reduced.
- 1 unexpected result was a reduction in heat. The trunk area was noticeably cooler after driving.

For installation I cannibalized my old pool board and used the wheels to roll the material smooth. I used a regular utility knife to cut the material and went through 5 blades doing so.

What is not show in the photos ( camera fail ) is that I also added this material under the trunk area inbetween the mufflers and the car body.
I used 7 sheets inside the trunk and 3 under. This does help quite a bit with the noise. For me it was a perfect solution because I wanted to keep my RPI exhaust. I want to be careful about recommending this for these reasons:

1. You are adding weight to the car.
2. It is a huge PIA to take the trunk area apart and very likely that you may break some of the interior plastic pieces while doing so. This will result in unexpected costs.
3. Once you install this stuff it is not coming out, so you are committed.

All that being said, it worked really well. It does not eliminate the drone and cabin noise; but rather, brings it down to an enjoyable level. In my case I have no problem taking the M apart. I actually kind of enjoy it. The RPI's are so much lighter than the stock mufflers that I did not mind adding the extra weight over the rear wheels either.