Noise levels for a 2.0 L FI set up - interior vs exterior padding Options

[Tdskip]

Good morning, hope everybody’s having a good week so far. I know that from the factory there was padding in the engine compartment as well as having an interior back pad. My question is if I put additional sound deadening on the inside and then the back pad is that roughly equivalent to the sound pad that was in the engine bay originally?

I’m sure not having the pad in the engine compartment does lead to increased noise, but not sure how dramatic of an increase that would be with a fuel injected car.

I know this is a subjective topic, but looking for experiences and thoughts if you don’t mind sharing them. I’d like the car to be civilized and usable for fall day driving without feeling overly fatigued ( which I am comfortable doing another vintage cars and don’t feel the need to have a modern vehicle to do ).

Thanks!

[Superhawk996]

I know this is a subjective topic . . ..

Thanks!

(IMG:style_emoticons/default/lol-2.gif)

@TdSkip . Don't take this the wrong way. It is not subjective.

There is a whole field of automotive engineering dedicated to Noise Vibration & Harshness. I've spent a small portion of my career doing this sort of work.

Forget whether you have FI or not. Aircooled engines suck for NVH. They make a lot of valve clattering, rattling, knocking, piston slapping type sounds when they are running perfectly.

Air cooled is not in any way comparable to a water cooled engine that has waterjackets surrounding the cylinders. That is why I absolutely LOVE aircooled. They are different and unique.

So know that whatever you do, you're starting at a HUGE disadvantage from a NVH perspective.

Bottom line, if you want anyting even resembling quiet(ish) you need an exterior engine pad AND a constrained layer damping material (Dynamat) on the interior and I'd still probably put the heavy factory inner pad over the top of that + some thin shoddy on the back of the back pad if I could fit it.

I think there was a whole seperate list in a different thread so I won't rehash that here.

The only thing subjective about it is what one person prefers vs. another but I assure you there is engineering science to use if you want to make it as quiet as it can be.

[bbrock]

Bottom line, if you want anyting even resembling quiet(ish) you need an exterior engine pad AND a constrained layer damping material (Dynamat) on the interior and I'd still probably put the heavy factory inner pad over the top of that + some thin shoddy on the back of the back pad if I could fit it.

^^^ This! (IMG:style_emoticons/default/agree.gif)

The sound deadening material needs to be matched to the type of sound being attenuated. The tar on the floor of our cars and foil-faced butyl mats (a.k.a. constrained layer) is good at attenuating booming noise generated by vibrating metal panels. Attenuating airborne sounds often use a fiber or foam pad. The engine bay back pad looks to me to be something of a hybrid. It is a fiber pad encased in heavy rubber. Don't forget that it is matched on the inside with a rubber mat.

I doubt that replacing the engine pad with only something like Dynamat is going to match the sound deadening of the factory pad but the best way to find out is with data. (IMG:style_emoticons/default/beerchug.gif)