Page Q-2 — Soundproofing And Insulation

Major Objective. Pontiac’s major objective in soundproofing and insulation is to completely seal and isolate the body interior from engine, road and exhaust noises. New body insulation and sound-deadener materials have been added to all series in 1968. In addition, all openings, that might allow noise to enter the car, have been covered with special body sealer.

A thick blanket of fiber insulation in instrument panel, roof, front kick panels and rear-seat shelf areas effectively isolates road noise. The firewall is backed with a heavy sheet of wood fiber and a thick mastic composition, sound-deadening material or rubber-faced molded fiber, depending on series. A thick, mastic-composition deadener is cemented to floor and underseat areas, front and rear. All models have new and improved noise barrier and insulation on the floor, and a one-piece insulation deadener blanket extends the full width of the car behind the rear seatback.

A heavy coat of mastic is applied to wheel wells and inner-door panels, and under the hood is a molded blanket of special fine fiberglass to muffle engine noise. To increase sound=dampening effectiveness, spots of bonding material, strategically spaced, are inserted between the inner and outer metal panels.

In all Pontiac series, weather-stripping along the roofline helps further seal the windows in the closed position. Even at the door drain holes, special rubber strips help dampen road noise. In all series, disturbing noises, that might enter the passenger compartment, are tuned out where possible. Even the steering column and accelerator-pedal shaft contain special seals, to insulate against engine noise.

In Pontiac series, such as the Catalina, Executive, Bonneville and Grand Prix, a sealing strip of foam rubber, specially designed to block out the sound of tire sing and other road noises, lines

the bottom of all doors. Along the door sills, a layer of uncured rubber, which tends to flow into crevices and fill gaps, creates a firm barrier against sound transmission.

Special Acoustical Features. Certain 1968 models have added acoustical features to enhance ride, comfort and quietness. For example, the upper-level ventilation system in Firebirds and Grand Prix permits the elimination of door control vent windows, for reduced wind noise. And, with the exception of convertibles, the Le Mans, GTO, Catalina Hardtop Coupe, Executive, Bonneville and Grand Prix models feature sound-absorbing, perforated vinyl-coated fabric headlining to effectively dampen noise.

In Convertible models, special cemented fastening of the top fabric at the center roof bow, plus a tighter seat at the windshield header and a taut cable in the side rail area, help minimize high-speed flap and wind noise in the top. Convertible also have a heavy cotton-fiber lining in the top storage well to muffle out noise in that area.

Additional Facts on Insulation.

In the modern car, it is important to insulate not only against noise and vibration, but also against damaging moisture, leaks, dirt, heat, cold, friction and corrosion.

The Pontiac body is scientifically sealed against water and dust leaks. Window seals are of specially compounded, durable live foam rubber. Door-glass channels have fiber-covered rubber lips around the top edge of the glass, not only as an effective seal, but to help minimize wind noise.

Corrosion protection is given special attention in all Pontiac series. On the body metal work, several different types of rust-proofing primers are used – including zinc chromate, special anti-rust primer and corrosion-resistant underbody primer. Also, many critical parts, in both body and underbody, are of galvanized steel for maximum protection against corrosion.