Katech_Zach

I found a little trick for reducing the drone inside the cabin. I dynamatted the heat shield above the mufflers. The customer whose car we did this on has a dynamatted interior and he said the drone reduction from doing this was another step equal to the reduction when we dynamatted his interior. The combination has significantly reduced drone. Dynamat is resistant to heat up to 350 degrees. This shield is spaced a considerable distance away from the mufflers so it should be able to withstand the heat. Here is a pic.

33036

The "customer" happens to be me...Jason is correct - I had Fusions installed as part of Katech Stage 1 (first car they had done w/ these) as I love the sound compared to OEM or others. Noise & drone was tolerable until I added (not Katech) Kooks headers and high flow CATs / X pipe. Interior noise tolerable for me (not wife) but drone became too much. Car used as DD and had one 600 mile trip with one butterfly stuck open (replaced by B&B) which prompted interior dynamat. Significant reduction in overall interior noise and drone, but still an issue < 2K.

Car was at Katech for new LS9X (ZR1) clutch install and while on lift and while discussing drone issues Jason came up w/ idea to add dynamat to heat shield. Bottom line...at < 2K drone probably reduced by 80% - you can carry on conversation and listen to radio w/ no problems. Easy fix and would recommend to all.

I have also purchased the cone header inserts from Summit that were described in another thread, but have not yet installed.

More to follow regarding this and the LS9X clutch...

Once again, kudos to Katech!

33036
Katech #29

GaryZ06

I will be looking into this cause my cammed Z with stock exhaust drones with stock exhaust valves open.....where can I get this stuff?

MChicado

Here's the website with all the info you would ever want. Note: Dynamat does make engine bay material that definitely can withstand heat!....if you are worried about the truck/door stuff maybe breaking down over time.

MC

Katech_Zach

We have it in stock. It's $20 for a 4 sq.ft. sheet.

yanniz

there is also dynamat extreme..

GaryZ06

Jason to install the Dynamat would the exhaust have to be removed or could it be done with the exhaust in place?

Katech_Zach

The mufflers have to be out to get the heat shield out.

GaryZ06

One more question....I know you put Dynamat on one side....would it be possible or beneficial to do both sides? Thanks

Katech_Zach

What this does is it isolates the sound waves traveling from the mufflers to the rear tub. Double the Dynamat would isolate it further. It could help.

spdmn75

how much material is required for both sides?

33036

Another way to "double" it would be to add dynamat under the rear mat (extending up sides) - which is what Katech did for me. Jason has some pix of this that, perhaps, he might be able to post these. The test case would be adding the dynamat without interior install to see what difference that would make and then, sequentially add more to see changes.

Maybe there are some "sound" engineers out there that can comment on the resonance reflecting issues that Jason (and I) had been discussing.

I also believe leaving the rear compartment cover in place also reduces some of the drone.

Bob
33036

Painrace

Will you please install in my car while you have it? GREAT idea.

Thanks,

Jim

Katech_Zach

Two sheets

Katech_Zach

Red C6 Z06

Wow, how much weight does that add to the car? That Dynamat stuff is like a thin sheet of lead!

33036

~85#...I don't race, so not a problem.

BTW is made the GY RunCraps sound much better!

Bob

Katech_Zach

I didn't weigh it but I know it's quite a bit. The C6RS has 75lbs of Dynamat but they also do the doors. Probably a little under 75lbs.

satans csex

Looks awesome but tooooo much weight!

Katech_Zach

Everything is a trade off. Luxuries add weight. This is good for cruisers and daily drivers. Not for racers.