sound deadening, engine compartment pad Options

[dlindzey]

there are at least two different versions on the usual parts sites-
aase $200
pelican $125
AA $200

any practical experience or obvious best choice in taking care of this need?

[Literati914]

..
Look at what stock is, look at the whole thing. hard rubber outer with the fiber (horsehair?), then the steel but your not done. The other side you have the fitted rubber/tar sheet glued to the firewall and the whole back pad. You take away any part of that sandwich and it will add noise.

To me just some dynamat or whatever is crap, I'd look to replicate that sandwich with modern materials.
It's going to have some weight, if it's a street car you have to live with that fact.

I've had two 914s with stock engine side pads.. both just seemed like loose-fitting, worn out rubber sheeting to me.. I didn't notice any layers to them. Maybe those were something other than stock (IMG:style_emoticons/default/confused24.gif) , IDK.. then the other side (you mean the back-pad side?), neither cars had anything between the back pad and fire wall. I'm sure layering would be effective at noise tho. Maybe dynamat on both sides?


.

[bbrock]

..
Look at what stock is, look at the whole thing. hard rubber outer with the fiber (horsehair?), then the steel but your not done. The other side you have the fitted rubber/tar sheet glued to the firewall and the whole back pad. You take away any part of that sandwich and it will add noise.

To me just some dynamat or whatever is crap, I'd look to replicate that sandwich with modern materials.
It's going to have some weight, if it's a street car you have to live with that fact.

I've had two 914s with stock engine side pads.. both just seemed like loose-fitting, worn out rubber sheeting to me.. I didn't notice any layers to them. Maybe those were something other than stock (IMG:style_emoticons/default/confused24.gif) , IDK.. then the other side (you mean the back-pad side?), neither cars had anything between the back pad and fire wall. I'm sure layering would be effective at noise tho. Maybe dynamat on both sides?
.

Dynamat is good for quieting the resonant booming/drumming sound of large panels like floors and doors, it is not good at stopping the airborne drone of an engine. That's where those layers come in. Different sound deadening materials are needed to address different noise sources. And even the constrained layer (e.g. Dynamat) manufacturers recommend adding a dense layer of padding under the carpet.

[bkrantz]

..
Look at what stock is, look at the whole thing. hard rubber outer with the fiber (horsehair?), then the steel but your not done. The other side you have the fitted rubber/tar sheet glued to the firewall and the whole back pad. You take away any part of that sandwich and it will add noise.

To me just some dynamat or whatever is crap, I'd look to replicate that sandwich with modern materials.
It's going to have some weight, if it's a street car you have to live with that fact.

I've had two 914s with stock engine side pads.. both just seemed like loose-fitting, worn out rubber sheeting to me.. I didn't notice any layers to them. Maybe those were something other than stock (IMG:style_emoticons/default/confused24.gif) , IDK.. then the other side (you mean the back-pad side?), neither cars had anything between the back pad and fire wall. I'm sure layering would be effective at noise tho. Maybe dynamat on both sides?
.

Dynamat is good for quieting the resonant booming/drumming sound of large panels like floors and doors, it is not good at stopping the airborne drone of an engine. That's where those layers come in. Different sound deadening materials are needed to address different noise sources. And even the constrained layer (e.g. Dynamat) manufacturers recommend adding a dense layer of padding under the carpet.

Right now, I plan to have Dynamat, acoustic foam, and then carpet on the inside. Once I hear it run, I will consider if and what to put on the engine side.

[digit3]

..
Look at what stock is, look at the whole thing. hard rubber outer with the fiber (horsehair?), then the steel but your not done. The other side you have the fitted rubber/tar sheet glued to the firewall and the whole back pad. You take away any part of that sandwich and it will add noise.

To me just some dynamat or whatever is crap, I'd look to replicate that sandwich with modern materials.
It's going to have some weight, if it's a street car you have to live with that fact.

I've had two 914s with stock engine side pads.. both just seemed like loose-fitting, worn out rubber sheeting to me.. I didn't notice any layers to them. Maybe those were something other than stock (IMG:style_emoticons/default/confused24.gif) , IDK.. then the other side (you mean the back-pad side?), neither cars had anything between the back pad and fire wall. I'm sure layering would be effective at noise tho. Maybe dynamat on both sides?
.

Dynamat is good for quieting the resonant booming/drumming sound of large panels like floors and doors, it is not good at stopping the airborne drone of an engine. That's where those layers come in. Different sound deadening materials are needed to address different noise sources. And even the constrained layer (e.g. Dynamat) manufacturers recommend adding a dense layer of padding under the carpet.

Right now, I plan to have Dynamat, acoustic foam, and then carpet on the inside. Once I hear it run, I will consider if and what to put on the engine side.

Any updates?

[bkrantz]

..
Look at what stock is, look at the whole thing. hard rubber outer with the fiber (horsehair?), then the steel but your not done. The other side you have the fitted rubber/tar sheet glued to the firewall and the whole back pad. You take away any part of that sandwich and it will add noise.

To me just some dynamat or whatever is crap, I'd look to replicate that sandwich with modern materials.
It's going to have some weight, if it's a street car you have to live with that fact.

I've had two 914s with stock engine side pads.. both just seemed like loose-fitting, worn out rubber sheeting to me.. I didn't notice any layers to them. Maybe those were something other than stock (IMG:style_emoticons/default/confused24.gif) , IDK.. then the other side (you mean the back-pad side?), neither cars had anything between the back pad and fire wall. I'm sure layering would be effective at noise tho. Maybe dynamat on both sides?
.

Dynamat is good for quieting the resonant booming/drumming sound of large panels like floors and doors, it is not good at stopping the airborne drone of an engine. That's where those layers come in. Different sound deadening materials are needed to address different noise sources. And even the constrained layer (e.g. Dynamat) manufacturers recommend adding a dense layer of padding under the carpet.

Right now, I plan to have Dynamat, acoustic foam, and then carpet on the inside. Once I hear it run, I will consider if and what to put on the engine side.

Any updates?

Sorry, not yet. it will probably be a couple of months (or more).