March 2023

Why the solid rear axle lives on at Revology Cars

Choosing a technological solution for marketing reasons is not the guiding philosophy at Revology Cars.

Take rear suspension design, for example. As builders of reproduction original Ford Mustangs, Revology’s engineering team has examined the pros and cons of switching from the car’s solid rear axle (SRA) to an independent rear suspension (IRS) design.

<strong>Why the solid rear axle lives on at Revology Cars</strong>

The following are acknowledged attributes of SRA designs:

  • Lighter, cheaper, simpler
  • More durable and robust
  • Easier to package
  • Favors straight line acceleration

While IRS designs bring these advantages:

  • More stable handling over bumps/potholes/uneven roads
  • Improved ride
  • Favors tight turns and undulating roads

Looking at the general automotive market, IRS is found on most of today’s cars but SRA is still the preferred setup for trucks due to the design’s robustness for heavy duty applications.  While it is true that IRS can handle bumpy and undulating road surfaces better than SRA, a well-designed SRA can match IRS where surfaces are relatively smooth.  SRA works better for hard launches and full-throttle acceleration than IRS, which is one reason why SRA is favored by drag racers, the other being the durability and robustness of the design.  

Tom Scarpello, Revology CEO and founder, says that as with any engineering decision, there are trade-offs.  “For Revology, the decision to use SRA was based on an engineering analysis of the pros and cons of each design and the applicability to the early Mustang platform,” Scarpello explains. “In the end, we determined there was limited benefit, and that too many compromises, in the form of additional weight, cost, complexity, reduced durability, exhaust routing and other issues, would have to be made to package an IRS in the platform.”  

The early Mustang platform was not designed for an IRS.  Even a major automotive manufacturer, with significant engineering resources, finds it challenging to package an IRS in a platform not originally designed for one.

“Ford’s 2003 SVT Mustang Cobra, based on the SRA SN95 platform, featured an IRS,” notes Scarpello. “It was heavy, expensive, and noisy, and the company dropped it on the upcoming S197 model. The clean-sheet design of the S550 Mustang in 2015 provided the opportunity to reintroduce IRS in a platform designed for it from the beginning.”   

Some companies promote new technologies even though the technology may not be the most suitable for the application, because of the perceived marketing value.  This is not the Revology way.  At Revology, the technology must stand on its own merits.  Revology designs its products to be the best they can be, given all the trade-offs involved.