Well, it ain't 75% but it does silence things a bit! The SRT intake at idle showed a 72 db peak reading & 91 dB's at WOT ( hood down but car sitting still - wasn't gonna lose that B&K by driving down the road!! ). Used duct tape to line the heat shield &, as Grush suggested, also the inner fenderwell w/DynaMat Super & retested. Lo & behold, the idle dB was 70 but the WOT dropped to 86! It still might be objectionable to some at that level but I like it just fine w/o the Dynamat. I agree with JB - the high pressure area upstream of the throttle body causes a pressure wave that no amount of Dynamat will silence but it WILL work to minimize vibration near the open element K&N filter.

 

I used carpet tape and grey corrugated 1/2" foam to line the inside of the entire "airbox". While I don't have any db readings, the noise under full throttle is definitely reduced to a much more managable level. BTW - What is Dynamat & where does one get it?

 

Dynamat can be picked up at your local audio shop. It's used as sound insulation for car audio systems.

Percy

 

Gene,

Just for kicks, why not line it with Deflex? They have a subwoofer panel which has deep valleys and peaks (looks like a very steep "V" when viewed from the side) that should deaden the noise. Just a thought...

Percy

 

A few of us have the new red AFE filter which Mo has supplied in his later HFI kits. Supposedly, it supplys like a quarter or a third more air over the K&N filter in earlier kits. The bigger filter was also suppose to be slightly quieter than previous.

 

P - Hey, why not!! Post up where I can get some online & I'll repeat the test - might even try ADV's method of carpet padding. I didn't realize that Deflex worked to reduce resonance - thought it was more like an apheriodic membrane. Refresh my memory, Master SQ!

 

Gene,

Typing you a message via email. This server just crapped out and dumped my message into the bit bin, then reloaded what was in the cache....result...no message was posted. $*@&@&!&!@*$%###!!!

Percy

 

One add'tl way to further silence the air sound would be to wrap the tube, but that would take away from the Looks department.
Sound insulation material could be tried around the right shock tower also; anywhere around the vicinity of the intake pipe. You may be surprised at the results

 

Interesting info. DBs increase/decrease exponentially. 150db is ear destroying loud not the 2x that 75db would lead some to believe. Dropping from 72 to 70db at idle is significant. 86 from 91 is very significant.

Wrapping the main tube may help. I have a thought, I have seen see through urethane tubing used for many applications. If some is available with a 3.75-4.00" ID it could be slipped over the tube and reduce sound while doing the least visual damage for this type of mod.

MG, "apheriodic membrane" now that's a scientific sounding phrase.

 

It is! It's a special membrane that is used for sub installs. Lowers q and increases response. Also good for very small interiors where space is of a concern.

Percy

 

Mean Gean,

Can you post a pic of your Dynamat installation? I've tried it with my setup, but I did not feel that the sound level has dropped much. Any help would be appreciated.

 

HL - I've already removed the Dynamat ( like I said, I like the sound! ) but all I did was cut pieces of the Dynamat Super into the shapes necessary to line the heat shield & fenderwell & secured them with duct tape. I really didn't find it a huge audible difference but the meter doesn't lie.