Authentic Design, Modern Engineering

You want to compare kits?  Start with the frame.  The artistry, strength, and complexity of the Factory Five Mk3 frame is reason enough to stop looking right here.  The beauty of our design is accentuated by the fact that it is stronger and more rigid than you’ll ever need. 

The Mk3 roadster frame serves as the centerpiece of the kit.  It is computer designed to be extremely strong yet maintain the beauty and elegance of early 1960’s race car frame designs.  The frame weighs 326 lbs. and is shipped as part of an assembled kit chassis, ready to accept bolt-on components.  The frame is a completely welded assembly and requires no welding, cutting or drilling.

We use an authentic 4” round tube design.  We feel strongly that a quality replica should have a period correct, 4” round tube frame, just like the original legend.  If you compare replica kit frames you’ll quickly find the Factory Five frame makes most other kit car frames look like lawn furniture rather than race-car construction. 

The original style round tube frame is literally a piece of art.  The tubular ladder style frames used in early 60‘s Ferraris and original Cobras are more than beautiful, they are representative of a period of automotive design that is legendary.   We chose to use this style of frame despite the difficulty and cost since a huge part of a quality replica is its faithfulness to the spirit of the original cars. 

Lastly, artistry is very important, but if the frame doesn’t perform, what good is it?  Vintage frames were used with the heavy, high torque, 427 FE motors of the day.  With these big motors producing 450+ hp and 500+ ft/lb. of torque, the original vintage AC Cobra frames displayed quite a bit of flexing under severe use.  We wanted the elegance of the original frame style, but we also needed to make it a lot stronger.  To accomplish this we did several things. 

• We added a backbone frame section and extra perimeter tubing that more than doubled torsional rigidity right off the bat.
• We increased the thickness and quality of the steel pieces.  The 4” main rails were increased in wall thickness to use .120” wall tubing (up from .095” in the original 1960’s frames). 
• The dash dash/cowl hoop is thicker .100” wall steel. 
• The cockpit and footboxes have a steel cage surround structure. 
• Triangulation bracing was added to a number of locations, namely the front suspension vertical supports, dash, rear sub-frame, and trunk. 

With increased wall thickness and structural upgrades, the use of better materials, and more consistent manufacturing methods, our frame is engineered to handle much higher horsepower and provides greater torsional rigidity than the original British built frames. 

When you see FFR cars winning national races or lifting the tires clear off the ground, check out the “straight-as-an-arrow” frame quietly doing its job.  Today’s Mk3 frame is the third generation FFR roadster frame and has benefited from more than 10 years of refinement and development.