The Ultimate M4S Insider

Dodge-PPG M4S Pace Car Designer Bob Ackerman Talks About His 'Baby'







Space buck at 3-D Industries.
Build of full-size M4S model based on Bob Ackerman's sketches begins at 3-D Industries studio.  On wall in rear, numerous small "wire frame" drawings produced from Bob's orthographic drawings by computer support personnel, and large side-view "tape drawing" (black photographic tape on Mylar) by Bob.  In foreground, "space buck" construction by 3-D Industries modelers consisting of foam core board cut to match wire frame sections and mounted on wooden "armature" (plywood box on caster wheels).  Chassis is not involved at this stage and wheels are only props. Windshield is foam core board.

Modeled in blue foam.
Windshield, covered with black photographic tape to protect it from damage, is Ferrari Berlinetta Boxer glass.  Wheel covers are foam on real tires.  Two lines below windshield marked position of a strut between two recessed areas, but that feature was dropped in favor of single recessed area.  Next step: thin clay layer to be applied over blue foam.

Assembling M4S body at SVI.
Assembling fiberglass M4S body parts at SVI. In the background, master metal craftsman, Ron Fournier.  In talk ing to allpar about the M4S, Joe Pappas credited Fournier with fabricating the steel body panels of the 175-mile- an-hour Daytona Turbo Z PPG pace car mentioned above.  Ron is apparently working on vertical stabilizer of the Daytona-type wing tried during M4S testing.  Ron was with Bob and the team of Chrysler aero engineers and SVI fabricators who took the M4S to Marietta, Georgia, for wind tunnel testing.  Sill below door opening has "NACA scoop" that was dropped in favor of Bob's custom styled inlet found to be aerodynamically better.


Prepared for wind-tunnel testing.
Car prepared for wind tunnel testing with long strands of black and white yarn held on with tape.  Tempo- rary wheels were eventually traded for BBS "spoke" wheels seen in other pictures.

Finished car at Styling Dome.
The build completed, Bob Ackerman posed with his M4S at the Chrysler Styling Dome at Highland Park.  He designed the car to race aerodynmic standards.  It's co-efficient of drag (Cd) of 0.293 compares to a Cd greater than 0.3 for most production cars, including the Corvette at 0.34 and some sedans at 0.35.  The car's coordinated lines show in the scissor door opening from the trimline encircling the body, and the rear cutline of the door lining up with the uniquely-styled side scoop.  The scoop is functional, feeding air to the intercooler, the rear brakes and the transmission oil cooler.


Test date, July 1985.
July 1985 at Mid-Ohio test track. In Bob Ackerman's design, juncture between M4S hood and windshield is a straight line.  "Most cars have a broken surface where windshield meets hood," Bob points out.  Black rubber valence below winged air intake "virtually closes off air flow under the car like on the NASCAR cars today."  Side mirrors were purchased by Bob at a motorcycle shop.  Photo by Eli Nichols.


Bob Ackerman at Ypsilanti, Michigan
Bob Ackerman and four of his design concepts on the theme, Return of the Luxury Coupe, exhibited at the Ypsilanti, Michigan, Orphan Car Show, Sept. 25, 2011.  Held by that city's Automotive Heritage Museum, the annual show is dedicated to innovative American cars produced by companies that no longer exist, like Hudson, Tucker, Kaiser-Frazer, etc.  The exhibit was organized by The League of Retired Automotive Designers.  Photo by Ron Van Gelderen.



Black and white movie picture. Black-and-white movie publicity photo shows the real scissor-doored M4S and The Wraith character in sci-fi garb.  The car was in Arizona for filming in February 1986.  However it never actually appears in the film.  In the movie, the dune-buggy replicas are seen with gull-wing doors.  SVI tech Steve Maki, who was in charge of the car at the location, reports it did get filmed once on a Sonoran Desert road.  He was at the wheel wearing The Wraith's helmet.  Steve says, "I went through the movie twice recently looking for the M4S but never spotted it.  Either that sequence ended up 'on the cutting room floor,' or they were just pretending to film."