story and photos by matthew mariani—aka "the fixer"
Matthew and I struck up an instant friendship. Not only did we go to the same art school and pursue the same major, we have uncanny similarities in creative endeavours. When I saw what he was up to with his 928, I naturally gravitated towards his idea.
Although his build is laid out on two forums, we thought it could be better structured on flüssig's site as a series of journal entries without the noise that forums usually create between the important bits.
Follow along as we create a condensed version of Matt's build peppered with in-depth commentary by myself and Matt.
Enjoy the journey--
Weight is the only problem with these outstanding Porsches in my opinion. They still look great and are very enjoyable to get in and drive after 3 decades. The current weight is 3300 lbs+ for my U.S. spec 1983 sunroof equipped model. The later 928 examples were well over 3550 pounds.
My prototype 928RS needs to be at that magic 10 pounds per horse-power ratio or better. At around 240 HP and 3300 lbs.
I don't want to just throw a super charger on this car. Big heavy cars with high HP figures do not excite me. For me, a simple, light and agile sports car with decent power is just way more fun; clearly, my 928 needs to go on a serious diet.
I don't want to cut or jawsaw the unit body or doors. I'd like to approach weight reduction like PORSCHE might have had they offered a 928 RS in 1983. This would have been a great Porsche.
Some 928 RS Build Details:
I always wanted a gulf blue Porsche. Just the thought of it gets me excited.
Most other colors would look bad with my car's navy blue interior, gulf blue will not and will get the RS idea across very quickly.
A 928RS will need hood vents to extract excess engine heat. The vent design should look 1980s, be subtle and placed in the correct location. If Porsche used them on the 1984 'Daytona Lightweight,’ I should do the same for a RS Concept 928. These engine bays get very hot. They fry all that is rubber and plastic. The intake tubes get extremely hot, venting is a must.
Designing a 'Ducktail' spoiler on a lightweight hatch. The famous 911 ducktail spoiler is something i want to explore on the 928 shape. It will be tough with the hatch frame dimensions, but since the hatch lock will be removed it is possible. It would not need to be quite as tall a spoiler as used on the 911 due to the fact that the 928 rear end is much higher than the 911's rear end. My ducktail design will not ape the 911 ducktail spoiler, it will be designed specifically for the 928 but hopefully capture the flavor of the original.
Weight & Power:
My goal is to get my 928 RS down to 2700 lbs. and bring the U.S. spec motor up in HP from about 240 HP
up to 270 and later with machine work up to over 300 BHP and naturally aspirated.
Porsche always added a little extra performance (at least 10%) to their special lightweight models. I want more than that.
Future 928 RS or RSR variants could put out well over 330 BHP at this lower weight. I will add larger interior diameter 'Euro' intake tubes and throttle body and specify the 'Euro' grind for its camshafts.
Compression ratio will also eventually be raised to 10:1 from 9:1.
An electric 'puller' fan is in place, the belt driven fan and heavy bracket are gone. The air pump is in the trash, AC components are all gone as well. My exhaust catalyst and heavy rear muffler have retired as too.
The aluminum 4.7 liter V8 already feels happier, revving smoothly and freely with terrific throttle response.
Power steering is on the chopping block and will be removed.
Gone will be all engine accessory belts but for the alternator, this alone adds horse power.
There will be no power windows or locks, no ac, no radio or need for speakers, no power anything.
The center console shall be shortened to just below the heater/demister controls.
A small battery will replace the OE battery. Lexan will reside in place of the hatch and door glass.
A GT3 inspired single windshield wiper will clear the rain droplets on the rare occasion if I am caught out.
The rear wiper and its metallic lump of a motor will be deleted. One sun visor as opposed to the four would be an obvious RS must have touch. Even the ignition key and fuel cap will be lightened in a Porsche way.
There will be no hood or hatch releases and latches and no gas assisted struts to hold them up. In their place will be lynch-pins and aluminum prop rods. The sun roof will also be removed and the opening filled carefully with pre-shaped 20 gauge steel.
The much ahead of their time hidden aluminum bumpers will be lightened. The heavy 3 - piece rear spoiler, rear wiper and power radio antennae and rear 'bumperettes' are already gone. The openings in the body for their attachment are neatly filled with mild steel and weld already. I plan to drill the hood hinges and the hatch frame conspicuously along with many more items for weight savings.
These touches will make a statement to onlookers when the hood is raised and held up with its aluminum prop rod.
I will use the 951 (944 turbo) wheels for this prototype RS. They are 16" x 7" up front and 16" x 8" out back. I like their deeper dish design over the 928 units.
Shorter S4 front springs will slam the car down. New suspension bushings and new Koni adjustable dampers will help the RS remain stable at the track.
Some other Major Design Features:
To Relocate the Ignition Key to the left side. This is simply a cool Porsche detail but not necessary.
A Simple, lighter interior and lighter upholstery is a must along with the removal of the heavy sound deadening.
Lighter front seats and steering wheel, lighter dash and instrument pod. All unnecessary electrics are to be removed.
The rear seats will be removed. Custom RS door cards, Perlon carpet, glove box lid deleted, lightweight dash and pod.
A clean, rear bumper cover without an exhaust opening. I’ll also delete all unnecessary elements of this Porsche including headlamp washers.
A lightweight, open and very loud exhaust set-up which exits at each side in front of each rear wheel. (this screams my Porsche motor is up front!)
This will be a much lighter exhaust design. I will use 1985- 1986 928 lightweight stainless steel tubular exhaust manifolds, these will save around 35 pounds over using the cast iron manifolds on my M.Y. 1983. They are also beautifully made. Then, to a custom made Y-Pipe which goes into a collector, and out the sides as shown.
A Subtle RS below the tach needle and a "DEPRESS CLUTCH FULLY BETWEEN SHIFTS" plaque on the instrument pod would be nice and recall the IROC 911s back in the day. Hartmut at North Hollywood Speedometer has my Instrument cluster and will make the graphic changes.
These are some of the design details which i intend to use to create a 928RS prototype.
If the car turns out to be as fun as i think, i hope to build many more.