And in rolls the SaaBeeru ... by Bradcr

4 minute(s) of a 145 minute read

Finally got a shot of my English Racing protune: 

  Nothing too crazy, but it definitely has felt better than my Cobb Stage 2. I'm finally getting into the soundproofing stage of the car. I did switch apps to an iOS app titled simply 'Decibel', in conjunction with iAnalyzer. I'll admit I finally tried it because it was used on Top Gear. I miss the graph from Decibel 10th, but in the end it isn't useful. The best thing about Decibel is its average, which has immediate refresh but seems like a real average, so setting sensitivity to 'low' produces a very smooth volume leveling which seems more accurate for my purposes (not to mention screenshots). I've combed different threads and forums to see where I could find the most agreement. First area of attack definitely is the vents in the rear bumper wells, typically done by stuffing in an old floormat. For my project, I took most of my instruction from sounddeadenershowdown.com. To that end, I picked up a 54 sq ft roll of 1lb/ft 1/8" MLV/mass loaded vinyl ($100 shipped from eBay), 3 40"x 80" sheets of y20 neoprene closed cell foam ($16 a sheet from Friendly Foam around Seattle), 3M 80 spray adhesive, industrial strength Velcro, locktite rubber/vinyl glue and tin snips: 

 I pulled the jack and took some rudimentary measurements of the driver's side vent cavity since it is more accessible. It looked like 12"x18" was the ideal size- I first cut a piece of the foam and pressed it into the cavity to test fit: 

 Seeing that it's a close fit, I cut a second foam rectangle and two from the MLV, and glued them together. Ignore the squares I left for Velcro, they weren't needed: 

 I pressed the panel I planned to use for the driver's side into place and marked where it hit the frame for the jack. From that I made these slits: 

 For the passenger side, there's just the restriction of the very tight taper at the rear of the car, so I made this slit to fold the piece properly: 

 All set, now I removed the anchor points on each side of the passenger side cavity and worked the panels into place: 

I bolted everything back together, started up and IMMEDITATE difference. While I'm measuring this project at 60mph in 5th, the idle and low speed difference of this little mod is where it's at. As for at speed I'm down to stock volume levels: Stock:

  Nameless Exhaust:

 And after Soundproofing:

 And here's why- a massive drop in higher pitched background noise from this:

 To this:

 Glad I got a heads up about trying the iAnalyzer app in conjunction, looks like I put the Dolby filter on a cassette tape with that graph. I'll pour over some other people's result notes and decide what to hit next.