MowbrayWRX

Hi all
Having just had the PPP fitted to my 02 Wagon, I must admit the sound of the new exhaust system is superb, its so throaty. However I have had to turn the radio up quite a few clicks and motorway driving can become tedious with the increase in the dB department .
The floor in the back of the new age Wagon looks well insultated, but I think there is quite a lot of sound coming through the skin of the back door into the rear compartment and hence straight in the car.
My question is has anbody tried to reduce the dB level by fitting insulating material inside the rear door. This question may have been asked before and if it has then I am sorry.

Any ideas on the subject.

PS And no I don't want to swap the BB for something else.

Tony

john banks

Try in the ICE forum. They like sticking Dynamat on everything

see here:
http://bbs.scoobynet.co.uk/Forum4/HTML/000580.html
http://www.chiark.com/scooby/icefaq.htm

JonW once posted this:

Dynamating the Impreza
======================
(My own experiences interspersed with info from other posts)

You will Need:
· The FAQ
· Foaming the doors guide
· Sounddeadening material as listed below

Warning: If you break or ruin anything doing this you’re on your own, this worked for me and I supply this information in good faith, errors and omissions excepted.

Notes:
· This guide is to be read in conjunction with the FAQ. And the Foaming the doors guide from this BBS.

Costs:
Bootmat
· Allied Carpets crumb rubber 2 Sq yards £11.98

Front doors
· Dynamat - 3 x 4ft sq rolls Dynamat Extreme £59.97
· Foam - 1" thick - £7.50

Front Floors
· 2 x 4ft sq rolls of Dynmat Extreme 39.98

Wheel arches
· Waxoyl underseal - 8.99
· Dynamat - 0.5 x 4ft sq rolls Dynamat Extreme £10

Boot Floor
· 2 x 4ft sq rolls of Dynmat Extreme 39.98

Front Doors:
------------
The minimum soundproofing you will need to do is to fit Dynamat (or similar) to the lower parts of the front doors, here follows instructions on fitting to the lower door skins as per previous posts, reproduced (and updated) here:

Remove the Door trim, speaker as per the instructions in the FAQ

Peel back the inner splash guard (clear plastic liner) from the lower half of the door being careful not to damage the mastic sealant. Use a piece of tape to stick it up out of the way.

Clean up the door panels where the sound proofing will go first with white spirits or meths and finish off with pre prep spray or contact cleaner from your local car parts store. You may find Subaru have generously given you a 3 inch square piece of sound proofing in the door, remove and save this as you can reuse it somewhere else on the car that’s not so important.

Start with the inner skin and take your time, rushing will cause you to mess it up and also to cut yourself on the door skin edges or the edges of the soundproofing if you are using alloy backed material.

For the outer door skin, cut about a 9-10 inch strip along the short side of the 4ft Sq Dynamat rectangle. This will give you the right amount to go from the bottom of the skin up to the middle (where the side-impact bar is on the inside, level with the groove on the outside). For anyone of normal anatomy the top half of the skin is out of bounds IMHO (see later as it may not be for you…)

To install this, start at front or rear - fold the piece you have in half, fold at top, backing paper out. Peel off the backing from the side facing you, as far as the fold, and let it hang down the back. Now put the piece into the door through the large hole, then make sure the bottom (non-sticky) edge is snugly at the bottom and corner of the door. Now fold up the folded bit, press down part of the top edge to make it stick, and you can stick it all down peeling the backing off as you go. Press it all down as before and repeat for the other (front or rear) half of the door. Then rub it hard onto the metal with something round (I used the end of a screwdriver handle - the ideal tool would be one of those little hard rollers used for making lino prints).

For the inner skin, clean up the metal work and then cut about an 8 or 10 inch wide piece (along the short side) of the Dynamat to cover the bottom third of the inner skin. Make a U-shape hole (open side at bottom) where the speaker will go. To do this place the Dynamat (with backing still attached) over the panel where it will fit and draw an approximate speaker hole on it with a pencil from inside the door (hand / arm through the long hole), then remove the Dynamat and cut the hole out with a Stanley knife. Save this piece. Then just peel part of the backing off and progressively stick it down and rub it into the nooks and crannies. Don't worry about chopping off the bit that covers part of the "hole" as I'm sure this baffles it all nicely. Use any oddments on the flanges around the large hole in the skin.


Now take the piece you cut out for the speaker and stick it over the other layer on the outer door skin, behind where the speaker will be.

You need to be a bit savvy as there's nothing Dynamat likes more than sticking to itself, but this "foldback" technique does the trick.


Belt and Braces approach:
With the speaker out and the plastic sheet peeled back from the whole of the bottom and the top rear corner you can access the top of the inner side of the outer door skin. Cut Dynamat to the approximate sizes needed to do this is 3 or so pieces, this is hard and fiddly work (small hands and thin arms helps) but it can be done.
Also, cut pieces of Dynamat and fit them round the edges of the large hole on the inside of the inner door frame, behind the hole for the speaker and also on other areas where vibration seems likely on the inside of the inner door frame (under the lock actuation rods and other areas you can get to with odd pieces of Dynamat).
You can also double up on what you have fitted as two layers will be better than one, the need for this depends on what product you’ve used in the first place.

Carefully reseal the plastic sheet or use lots of duck tape to get the plastic sheet back down and the wires secured and flap-free.

Front Floors
------------
Put the seat all the way backwards, vacuum the carpets and lift out any mats.
Remove the treadplate trims - prise up the 4 large square buttons with a blunt instrument. There are also a few buttons on the forward edge of this trim too. Then to lift the carpets use a screwriver to unclip (basically just put the screwdriver in and twist) the white clips on the carpet edge. Look for other clips under the pedals etc and remove them by unscrewing them with your fingers. You should now have access to the floor. Vacuum and dynamat liberally as much as you can.


Boot:
-----
Rear Wheelarches - Pull up the boot mat. Follow the side trim to its edge just inboard of the rear lights, unscrew the lower trim clip and prise out the button above. The Drivers side has another button just behind the wheel arch and the passenger side has a hidden clip at the same point. Swing the trim into the boot space. Remove the jack. Remove these trims one at a time and cut strips of Dynamat and fit to the outer edge of the wheel arch (be sure to reconnect the Aircon drain if dislodged on the drivers side. Then add Dynamat to the inside edges of the wheel arch. Refit any trim that was removed and dont forget the jack.
Boot Lid - fitted Dynamat Extreme in the small indents in the centre of the bootlid inner skin. Also fitted off cuts of DE into the gap and onto the bootlid skin behind the Subaru letters.
Spare Wheel well - lift out the boot mat (large screws on the back of the fold down seats), spare etc and dynamat the metalwork. Also fold down the seats and you can see two inspection plates and put material on these too. Finish off by placing Dynamat on any metal surface you can see really.
Jack up the car and remove the rear road wheels and clean the underseal, leave to dry thoroughly and then paint on extra coats with Waxoyl.

Boot Mat
--------
I used Crumb rubber carpet underlay mat cut to same size /shape as original boot mat then duck tape the edges to stop ‘fraying’, cut slightly long and looped down under rear seat mounts. Put original boot mat back on top. Stuff I got had a nice purple / black hue to the rubber but sadly this goes face down.


Footnote: I did try and do some proper scientific tests with a soundmeter but the unit I had borrowed was not the best and the sound levels were all over the place. It did get better though but not by an reliable / measurable mark on the unit I had.


Note: beware when fitting alloy backed products that you re careful when fitting as the edges can be sharp (especially when cut with a Stanley knife) and cut you to ribbons on the ends of your fingers which aint good…


[Edited by john banks - 5/31/2002 11:22:46 PM]

[Edited by john banks - 5/31/2002 11:26:16 PM]