Resonation reduction

[Pa Pooh]

Having installed the Power Effects exhaust system (love it) and gaining severe resonance, I installed the sound deadining material suggested by another forum member which helped a lot. I would appreciate all and any imput from others who may have ideas to further improve elimination of resonace/road noise. Thanks (btw, I only installed the material in the cargo area of my coupe):SANTA

 

[Pa Pooh]

Hello,
I would like any and all information or suggestions from other members about sound dampening ideas for C-4 Corvettes. I installed a Power Effects (which I love) and have put dampening materials in the cargo area which helped. Thanks, David

 

[Vettelt193]

adding a crossover pipe, from one side of the rear Y to the other is supposed to help resonance. try to run a search in these forums about resonance, you should find many posts about it.

 

[sothpaw]

crossover pipe

Try a cross over pipe. I think it should be placed where the
tubes first split to go to the mufflers (Y).

Ask Redbob here--he's an acoustic expert.

I would be in the same boat as you, I want to get the PE, but
I know that there will be resonance. And it sucks when you
spend that much to have to cut the nice new pipes.

 

[sothpaw]

pe

Are you having the unacceptable resonace at open or closed
position? I would hope with it closed and your material change,
it would be quiet.

 

[Pa Pooh]

With the control in the closed position; the sound is almost enjoyable. There is enough improvement that now I hear the road noise again! I am interested to know if anyone has gone beyond what I have installed, and please don't misunderstand,
I love the sound of the Power Effects (and the extra power) but I am a musician and I really want to isolate the interior in order to be able to listen to music at a normal level. ( I have quite a bit of hearing loss from too many years in front of loud amps} Thanks to all ......David

 

[Edmond]

I have a Flowmaster catback system installed and it's gotten louder since I've put them on. When I'm sitting at a light, the rumbling would annoy the #@$! out of anyone else, but not me. I just love the rumbling!

 

[vettered91]

I had the same problem in my LT1 and did alot of research everywhere, but the best answers in this forum. You need to add a crossover tube between tubes as far back as the spare tire lets you (between resonator and spare) it workwed very well for me. (I have long headers, no cats and Magnaflows)

Before I did it I read that it works better at the rear end and I saw catalogs of aftermarket sistems showing the pipe at the rear! (MidAmerica is one of them)

I hope you can solve the resonance and enjoy!!!

 

[grapeknutz]

Try a Dr.Gas X crossover this will reduce most resonance, I know I installed this on my 92 LT1 and the power increase is nice too!

 

[lt1vert]

these should help

It helps to have your tips go 1/4" past the bumper. This allows most of the sound go straight out instead of bouncing back towards the interior when they're behind the bumper.

 

[vader86]

Well the only way to eliminate it is to plug up one outlet on each side.

extending the tips and adding crossover pipes will help too

but resonance is just a problem we have to deal with, the rear hatch glass makes the interior one big resonance sound chamber

 

[Hotred94]

There's a steel box channel underneath the rear hatch floor between the floor and the spare tire. It helps to put some foam padding on top of this channel to support the floor panel. It will dampen out some of the vibration.