Old + New =  One Helluva Ride!

  Test-driving the  GB Motorsports Boss 5.0 Roadster.

  By:  David Stevenson 

  What do you get when you cross the popular Ford Fox platform, vintage 60’s styling and a plethora of aftermarket parts?  Here’s a hint, this combination brings to life a modern performance vehicle that rekindles the spirit and soul of yesteryear.   If you haven’t already guessed, the car in question is the GB Motorsports’ Boss 5.0 Roadster.

  First introduced as the GB Mustang Roadster back in 1998, the Boss 5.0 is a retro styled roadster based on the now famous Ford Fox chassis.  The body design consists of sturdy hand laid fiberglass wrapped around highly modified underpinnings.  A trusty 5.0-based engine with a slew of go fast goodies supplies motivation.

  The advantages of this combination are pretty obvious.  The Ford Mustang 5.0 brought about the performance revolution of the mid to late 80’s. Since the Fox based Mustang outsold ever vehicle in its class throughout its long production run, Fox platform vehicles are still plentiful.  Subsequently, the amount of aftermarket parts available for the Fox chassis cars is now enormous.  Lastly, whether you like it or not, retro is in.  What better design represents the classic muscle call era than the original Ford Mustang?  The Boss 5.0 takes some of the coolest Mustang lines of the past and morphs it into a sleek but beefy modern roadster design.

  The Boss 5.0 is a great performer but its greatest asset is it’s striking good looks.  When you take one out for a ride, be prepared to stop traffic and answer a lot of questions.  I recently took one out for a long drive through LA and was amazed at the response of curious onlookers.  When filling up at a gas station, it emptied out all of the mechanics from the garage bays and almost caused a traffic accident when an admirer decided to back up on a busy street to get a better look.  The amount of points, stares and jaw drops is a real ego booster when driving one of these machines.  I must admit I felt a little bit bolder after driving one!

  The Boss 5.0 Roadster’s design is not only visually appealing; it’s also fully functional.  Large front grille openings reminiscent of early model Mustangs help feed fresh air to the fender mount cold air intake and oversized aluminum radiator.  Trapped engine compartment heat is extracted via a front hood venturi system, while Shelby like side scoops in the front and rear assist in keeping the massive Cobra spec brakes from overheating.  In a true roadster design approach, dual speedster humps help direct air over the passenger compartment.  Air passing over the body is then caught by a deck lid mounted wing in the same fashion as the Mach 1’s of the past and present.  This is not just a show piece, the GB spec wing actually increases the down force to rear of the vehicle, allowing for better stability and grip in high speed driving situations.

  If the Boss 5.0’s looks didn’t get your attention, 360 rip snorting horses at 6,000 RPM will.   The fully balanced 5.0 based 306 cubic inch motor features 10.1 compression, a Holley System Max EFI engine package and a complete Lunati spec valvetrain.  This revised engine combination allowed an increase of over 25 horses from the previous Boss 5.0 set up.

  A BBK cold air kit feeding to a Pro Flow Technologies 75 mm air meter and Holley 70 mm throttle body package handles the deep breathing requirements.  Octane is supplied by an Accel fuel system featuring 24 lb injectors, 190-lph pump and a fully adjustable regulator.  Accel high voltage distributor, coil and wire set up generate the necessary spark to ignite the above air/fuel mixture.

  Spent gases are expelled through a tough sounding free flow exhaust system featuring Flow Tech headers, a custom dual cat h-pipe and Hooker Aero Chamber mufflers.  This combination makes for a high-pitched tone that is less obnoxious and more civilized than other systems on the market.   This is especially welcomed considering the top less characteristics of the Boss 5.0 design.

  What good is all that power if your drivetrain can’t handle it?  The 322 ft/lbs of torque making their way to the pavement is corralled by a Ford Racing King Cobra clutch, Hurst close ratio shifter, Tremec 3550 trans and Ford Racing traction lock 3.55:1 equipped 8.8 rear end.

  Thanks to a custom fabricated and modified Fox unibody chassis, the Boss 5.0 is extremely rigid.   Full length boxed sub frames are incorporated into the floor pan and are crossed braced with additional frame supports located under the doors.  A structural cage located in the rear storage compartment/trunk supports the rear bodywork.  For additional rigidity, the rear shock towers are connected with a boxed steel brace.

  Despite all this reinforcement, the fully equipped Boss 5.0 tips the scales at a lean 3360 lbs wet.  This is mostly due to the absence of thick sheet metal body panels and the heavy convertible top.  Just for comparison, a comparable 87-93 5.0 GT ragtop weighs just under 3,650 hundred pounds.  

  Road manners are tight and precise due to a Maximum Motorsports  “Grip in a Box” rear suspension and adjustable camber caster plates up front.  Adjustable rear lower control arms allow complete tune-ability of the ride height while a torque arm set up properly plants the tires during full throttle stabs.  Front tires measure 245/35/18 while larger 275 mm width steamrollers out back keep the rubber glued to the road.   In addition, a beefy panhard bar keeps the axle properly located when diving the Boss 5.0 aggressively in the turns.

  Even though the Boss 5.0 sits on a rigid, polyurethane equipped chassis, its ride is surprisingly smooth and forgiving.  This is accomplished by utilizing progressive/variable rate H&R springs instead of the more racy linear rate options.  Progressive rate springs feel soft under normal driving conditions but really tighten up when the car is pushed hard in the corners.

  Braking in the Boss 5.0 is as easy as squeezing the pedal. Custom 18” aluminum US Wheels expose modern SVT Cobra binders measuring 13” up front and 11.65” out back. The combination of this large brake system and the lightweight Roadster make for some quick and effortless stops.  

   The Boss 5.0 is a very capable performer that bridges the gap between old styling and modern performance.  It’s unique body style and exhaust note screams “look at me” while its breath taking performance captivates the performance enthusiast in us all.  Modern performance and classic styling, what more could you ask for?

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