Old cars don’t have to creak and groan: Powerflex urethane bushings to the rescue | Project Porsche 911 Carrera

Update by David S. Wallens to the Porsche 911 Carrera project car
Oct 7, 2022 | Porsche, Carrera, 911, Bushings, Powerflex, Porsche 911 Carrera

Photography by David S. Wallens

Things that often define older cars: timeless lines, classic styling and, sadly, a few creaks and groans.

Our 1984 Porsche 911 Carrera was not immune from the aging process, and the cries from the suspension had become rather noticeable. The car simply sounded old and tired.

The easy fix: Turning up the radio.

The proper fix: Fitting fresh suspension bushings.

A visual inspection showed that some bushings no longer looked so fresh. They did not resemble their original shapes.

We had a few choices here: stock rubber bushings or something a bit sportier. We didn’t want to go anywhere near the full-race side of the spectrum–no track-ready, spherical bearings here–but how about a step up from stock?

Powerflex USA sells urethane bushings for a wide range of cars and has our 911 on its list.

The company offers three different product lines, too:

Street: Stiffer than stock to keep the tires properly planted.
Race: Stiffer than the Street bushings and intended for those headed to the track.
Heritage Collection: The stiffness of the Street bushings but in a stealthy graphite gray color.

The actual durometer rating of each bushing can vary, though, as it’s not a one-material-fits-all situation. Each piece is engineered for a specific application–voids can also be used to control flex–so the material found in a lower control arm bushing for Vehicle X might be harder or softer than an upper shock mount for Car Y. Some solutions might also mix materials for proper control.

Generally, the Street series bushings have a durometer rating of 65-80 while the Race bushings have a 95-durometer rating.

The Heritage Collection sounded like the perfect solution for us. Call it a sporty upgrade that won’t degrade the car’s street manners. And after the work is done, the chassis will still look stock.

Will these bushings be too stiff? We’ve been running the same set of Powerflex Street bushings in our autocross Miata for 20-plus years without issue or complaint–no harshness, no binding, no hardware problems.

We recently installed the company’s differential mount in a BMW M3. And, again, no issues afterward.

An added bonus regarding the Powerflex bushings: A lifetime warranty along with long-lasting, stainless-steel hardware.

The Powerflex bushings for the Porsche just arrived, and we’ll get them mounted soon. Some initial impressions worth mentioning:

Each bushing is marked with a part number and comes in a package that’s clearly marked with the part number and description. Presentation and organization count, right?

As necessary, the insides of certain bar bushings are textured to retain lubricant.

That lubricant is included as needed.

More to come soon.

The Powerflex parts that we ordered for our 1984 Porsche 911 Carrera:

[PFF57-403-20H] Porsche 911 (74 - 89) Front Sway Bar Bushing - 20 mm (Heritage)
[PFF57-405H] Porsche 911 (1965 - 1989) Steering Column Support Bearing Bushing (Heritage)
[PFF57-406H] Porsche 911 Classic Front Strut Top Mount Bushings (Heritage)
[PFR57-410H] Porsche 911 (1965 - 1989) Rear Trailing Arm Inner Bushing (Heritage)
[PFR57-409H] Porsche 911 (1967 - 1989) Rear Trailing Arm Support Plate Bushing (Heritage)
[PFF57-209-18H] Porsche 911 (77 - 89) / 944 S2 & Turbo / 964 / 968 / 993 Rear Sway Bar Bushing - 18 mm (Heritage)
[PFR57-413H] Porsche 911 Classic Rear Shock Upper Mount Bushings (Heritage)
[PFR57-415H] Porsche 911 (1965 - 1989) Engine Mount Bushing (Heritage)
[PFR57-430H] Porsche 911 (1965 - 1989) Shift Rod Coupling Bushing (Heritage)