Successful sound deadening for headers?

[ls1frc]

Hey all, I am enjoying my 6.2 swap very much. One thing that is really starting to get on my nerves is the header "tinny/airflow" sound you hear constantly in the cabin. It wasn't as bad on my 5.3 because of the lower lift cam and smaller engine. But on the 6.2 it is starting to irk me. Basically makes the engine sound like a junker as you accelerate lightly. Still sounds amazing at WOT though.

I have a lot of experience with headers on my previous cars and never had this sound, I think it's just the way the pipes have a sharp bend off the driver side header as it goes into the y-pipe, so you can actually hear the airflow.

I was considering pulling the seats and carpet and added some insulation to the floorboards and firewall area. Do you think this would make a difference? I also saw dynamat has a hoodliner as well.

Can anyone point me in the right direction of which material to buy?

TL;DR, trying to reduce valvetrain/header noise in the cabin.

 

[mikeyss]

The firewall has a thick pad already, but it ends just under the gas and brake pedals. After that is just a small layer of jute attached to the carpet. If you add deadening to that area as well as inside the door skins, most of the noise is gone.

 

[ls1frc]

Ok the y-pipe connection is right in that area that has no padding. Must be it. I will give it a shot.

 

[FrankU]

Coat the headers with Swain coating.....worked for me.

 

[ls1frc]

Researched for several hours. For pure sound blocking, you want mass loaded vinyl on top of closed cell foam. You can buy them as raw materials and try to combine them, but screw that. So I just spent the money and bought Second Skin Audio Luxury Liner Pro, which has the MLV on top of the closed cell foam already for easy installation.

I will do as high up the firewall as I can without removing dash and do as far back towards the seats as I can. Will report back results once done.

 

[ls1frc]

Coat the headers with Swain coating.....worked for me.

Did you have a before/after comparison? I may do this as well.

 

[ls1frc]

Also during my research, it was suggested that Noico sound deadener is just as good as the Dynamat at a fraction of the cost. I bought some squares and will lay that down underneath the vinyl layer.

https://www.amazon.com/Noico-deaden...dchild=1&keywords=noico&qid=1616945898&sr=8-3

 

[91RS]

Also during my research, it was suggested that Noico sound deadener is just as good as the Dynamat at a fraction of the cost. I bought some squares and will lay that down underneath the vinyl layer.

https://www.amazon.com/Noico-deaden...dchild=1&keywords=noico&qid=1616945898&sr=8-3

It is most definitely not. The best sound deadener you can buy right now is Resonix. Second place goes to Dynamat Xtreme. Other than those two, don’t bother.

 

[FrankU]

Did you have a before/after comparison? I may do this as well.

No comparison sorry. I've been Swain coating my headers on various cars & trucks since the 80's. I swear by it for noise and heat.

 

[petethepug]

CCF/closed cell foam. The stuff you find in egg crate type shipping boxes rates at the top. All the stuff mentioned here will get you where you need to be.

I run a German made supercharger, a g lader, or a lysholm on a tiny 1.9L motor in our 90’s era VW. I don’t run headers simply because the motor jumps around too much and breaks all the welds.

That specific tinning sound was present in this tiny VW motor from the increased flow, lightweight internals and aggressive cam. Ceramic coating the exh mani & down piping cut the tinning sound way down and, as a more important benefit, it cut the under hood temps down by at least 100*

Again, a combo of anything mentioned will be a win. In our VW, running Hushmat in the firewall, roof and floor, CCF in the rear wheel wells (just crammed in) and ceramic coating the exhaust components completely transformed the car into a Lexus quiet ride.


Sent from my iPhone using Tapatalk Pro

 

[ls1frc]

It is most definitely not. The best sound deadener you can buy right now is Resonix. Second place goes to Dynamat Xtreme. Other than those two, don’t bother.

Ok I won't bother installing it then. Do I even need the CLD under the MLV then?

 

[91RS]

Honestly, for what you’re trying to accomplish it may not be worth it for you. Deadener/CLD is mainly for panel resonance which is lower frequency and the header noise you want to block is higher frequency. The main thing I would consider is not wanting to do it twice, especially if the Luxury Liner is adhered to the floor. It is my understanding that doing the floor with CLD doesn’t get the same results as say the doors or roof since most vehicles have at least a little deadening on the floor from the factory. The Luxury Liner is probably the right product for you but I might go ahead and put down a little CLD under it. Not 100% coverage though.

I’ve been going back and forth on what I want to do to mine. I wouldn’t mind blocking some road noise but I don’t really want to block any exhaust noise which isn’t possible to block one and not the other. Even if I block road noise there’s still wind noise that can’t be fixed. I was planning on doing something when I replace the carpet, which I haven’t even bought yet but need to do soon before it’s discontinued. I do really want to do the roof but that’s a lot of real estate so it won’t be cheap.

 

[ls1frc]

Thanks. From what I read, full coverage isnt needed anyway. I think ill buy the bulk kit and use a few squares on the floor under the luxury liner. Then use the rest in each door panel and be done with it.

I am also leaking at the ball socket connection and every single slip fit. Im confident I can fix the slip fits with the 750 degree RTV but I never had any luck at the ball socket connections with it.

 

[ls1frc]

Was gonna put the stock exhaust back on and be done with it..

Then I saw how TINY the pipes are. This will probably lose 40+ hp. No way man lol.

 

[91RS]

Easily. I found a video on YouTube when I was deciding if I wanted to buy headers and I think it was LMP did a before and after dyno and just long tubes and tune gained 50whp on an otherwise stock truck.

 

[ls1frc]

Easily. I found a video on YouTube when I was deciding if I wanted to buy headers and I think it was LMP did a before and after dyno and just long tubes and tune gained 50whp on an otherwise stock truck.

Yup! I just hate the resonance, driving me nuts. I hope the mats help!

 

[ls1frc]

Ok so one sound is "solved"

In addition to the resonance, my cammed valvetrain is quite loud in the cabin around 2k rpms. I put in Redline oil, which is a true ester based oil with more zinc and tons of moly. I can't believe it, but it actually solved the noise. All I hear is the resonance from the headers now, which is even more pronounced now haha.

Next week the mats will get here. Crossing my fingers.

 

[91RS]

The Redline oil is the bomb. The valve train in my SS was so loud after I did the cam I thought I messed something up. I’ve changed both trucks over to it now also. I like the header racket though.

 

[ls1frc]

The Redline oil is the bomb. The valve train in my SS was so loud after I did the cam I thought I messed something up. I’ve changed both trucks over to it now also. I like the header racket though.

Man I couldn't believe it. I must have spent 200 dollars at walmart over the last few months trying different combos. This is the first one that made an audible difference.

I will do 5w-30 summer/0w-30 winter and do 6 month OCIs in each. Which filter are you using?

 

[91RS]

I do 5W-30 year round here in GA, not sure where you are. I use the Royal Purple RP-48. When I researched oil filters last it was one of the best synthetic medias.

I want to change my transmission fluid to Red Line also but it has 150k miles on it and supposedly has the "crappy" early seals since I have an 08 so I'd just hate to spend all that money on new fluid and then something go wrong with the transmission and I have to buy it again. My other truck is a 12 but has 187k on it now so same story there just because of the mileage although that transmission shifts better than my 08.