INTERIOR & SOUND SYSTEM

The interior has been a challenge. The original was stripped out entirely and I've been piecing together a black interior using as many factory late model parts as possible. The most significant additions are:

-Black leather sport seats
-Complete 924S black carpets
-Leather wrapped 4-spoke 360mm factory sport steering wheel
-Early 944 black dash & crested lock glovebox
-Early 944 black door cards with speaker cut-outs
-Late 944 leather covered handbrake
-eDead sound deadening material (butyl based)

The ridiculously time-consuming sound-deadening project.

After really getting fed-up with the low quality aftermarket carpet set I bought, I decided to replace them with a factory set from a 924S. Things snowballed from there.

The factory sound deadening foam/mat on the interior of the firewall was literally disintegrating into pieces. The hard tar-like deadening adhered to the floors was also lifting in places and was brittle all over from years of battery tray water leaks.

I decided to pull all of it up.

The firewall insulation came off easily. The insulation in the floors had to first be chiseled off with a screw-driver as well as the insulation covering the tunnel. Then, I used two bottles of goo-be-gone to remove the remaining adhesive followed by wiping it down with alcohol. There was one area in the passenger side that had some rust bubbles starting so I scraped it down and brushed on some POR-15 to seal it up.

Applying the edead sound deadener was actually really satisfying. It's simple to peel & stick and it cuts easily with a utility knife. At first, I wasn't sure how well it would deaden the sound. After getting everything covered, the difference was astounding.

After laying down 2-3 or more layers of edead I glued down a layer of generic home carpet foam padding over the tunnel, floors, and along some of the interior firewall.

The area to really pay attention to is the rear of the tunnel. For some reason it gets very hot back there and you need quite a bit of interior heat shielding. After about 4 layers of deadening, one layer of foam padding, and a layer of carpet, I can still feel that it is warm if I press my hand right against it!

The interior door sills also had a lot of resonance when knocking on them. So did the sheetmetal area in front of the doors. There is little to no factory deadening in these areas and I believe adding some helped quite a lot.

Finally I got to glue the carpet down and bolt everything back together! This was a tremendous undertaking, but the result was better than expected. With the windows up and roof secured, it's as quiet as a town car inside - except for the quiet low pitched droan of the exhaust, which sounds like music.

More Interior

I couldn't pass up the seats. I found a great deal and they're in almost perfect condition - quite a find for ~27 year old leather. They sit lower than the late-944 leather power seats I was using.

I tried a new "molded carpet kit", but it ended up being the most ill-fitting item I've bought for this car. The "mold" was asymmetrical on the front carpets. The quality of the carpet and the stitched edges had lots to be desired. I lucked out and came across a complete carpet set out of a 924S that is in excellent condition. Nothing has the fit and quality of factory carpet!

I opted for the 944 dashboard because it has a much nicer grain to it than the earlier 924 dashes. The 944 dash it softer and has more of a leather look rather than the molded plastic look of the 924 dashes. Other than the grain the early 944 and 924 dashes are identical.

I picked up a VDO -30 vac to +15psi boost gauge on ebay (they are no longer available new). I also have an oil temp gauge and volt gauge. I have oil temp and oil pressure gauges in the A-pillar pod, and boost and voltage in the center console. I'm hoping to clear up all this gauge clutter and replace them all with a small Liliput touchscreen mounted where the center speaker grill is. The MS interface gives you a view of 8 gauges that you can customize. That will take over boost and voltage and I'll move the oil pressure and oil temp gauges into the center console and rid myself of the A-pillar gauge pod. I think it sticks out like a sore thumb...

The Heater
This was the big project- updating the awful 931 heating system to the much improved early 944 system. The conversion is painful at best. Here is the list of what needs to be replaced-

-944 Center console (different heater conrol mounts)
-944 Center gauge panel (also has different clips for the heater faceplate)
-944 Control face plate
-944 Slider assembly
-944 Fan switch knob (off-1-2-3)
-944 heater box & blower
-944 heater motor cover in the engine bay
-944 heater box mount (center mount)
-944 heater core
-944 under dash ducting
-944 heater control valve (it operates opposite the 924 valve and has more range, also has larger hose connections- you'll need a little grease on the hoses to slide them on).

The biggest problem with the conversion is that the 944 battery shelf is cut differently than in the early 924's. The hole cut through the shelf that the blower pulls fresh air through is set about 1/2" frontwards of the 924 hole. In order for the larger 944 heater blower to clear the windshield wiper mechanism, windshield sheetmetal, and dash and trim, the hole in 924 shelf has to be moved forward by this 1/2". I ended up cutting a box around the perimeter of the hole on the 924 shelf, removing 1/2" from the front of the box I cut just in front of the hole.

I had a bodyshop weld the box back in, now 1/2" forward. They used spacer of 1/2" long sheetmetal to fill the gap. Some tack welds, and the rest is sealed with some magical glue they have. Then a swath of POR-15 to keep it forever sealed. It turned out great - no leaks, and the heater box fits. Now everything lines up perfect and the 944 heater box will slide right in. Whew! And yes, it really is worth it to keep my toes warm in the winter!

The remaining tan to black interior bits are taken from my '77 924 with a black interior. Some of the grain pattern is slightly off, but it will work until I get the rest of the pieces from an early 944.

Stereo

This Alpine deck is able to take over my Ipod controls when I plug it in to the cable. Now I don't have to scratch up all my cd's and clutter the car with them. I'm happy with how it matches the interior - not too flashy. The speakers are 4x Infinity Kappa 4x6" plate speakers. The front doors on the 924 didn't come factory fitted for speakers, but I was able to cut a small amount of sheet metal out to make them fit easily enough. I used the speaker cutouts in the 944 door cards as a template to get the correct position. Final fitment didn't require a spacer like I expected, however, I badly need speaker covers for them.

All four speakers are routed through a 50Wx4 Alpine amp that is mounted in the rear wheel cubby. The amp made a dramatic improvement in the clarity of sound.

Still on the list is to pull off the door cards and cover them with the soundproofing and put some foam on the door skin directly behind the speaker. This is supposed to help midrange, which 4x6" speaker inherently lack.

At the recommendation of a fellow Porsche addict, I added a Kenwood powered subwoofer to fill in the low frequencies. The Kenwood sub offers a nice tight punch when needed and the remote the comes up is handy when I recording comes on that needs a little more or less bass volume.

A final note on the Infinity fitment- the rear speaker pockets required some grinding to open them up a bit for the mid-range speaker to slide in. There is, however, plenty of rear clearance in this location.