For the Love of Cornering, an RDS-05 Story


For the love of cornering is right.  We started this rear sway bar project in 2011 with a blade style bar.  This style is commonly used on the Mazdaspeed3 vehicles in the Grand Am Series.  We fab'd up some angle iron and 1-3/8 (35mm) round stock.  It was fairly quick to prototype and get on the car to test.  

The bar ended up with the nickname Iron Man.


After about 4 months in the field, we found that we needed a stiffer bar.  We wanted  to increase the stiffness (lbs/in) to combat the hatch of the 3 and get more oversteer.  The Grand AM MS3 vehicles use massive OTS (off the shelf) end-bar blades ($$$) and much thicker bar stock for their rear bars.  These bars do not fit in a factory application though... wheel out the cutting torch.  

We wanted to test a rear sway bar with increased stiffness similar to the Grand Am-style bar while still retaining the fitment to factory components.  With the added benefit of CNC (Computer Numerical Control) bending, the creation of this massive S.O.B. (Son-Ova-Bar) was possible.


This is our 1-3/8" (35mm) prototype bar bent via CNC bender.  It fits factory components with no cutting or welding.  We ran it for about 45 days and a couple hours on the interior road course at the Daytona International Speedway.  Although 35mm looks like a monster, it is too stout of a bar for the MS3, especially when using with the factory front sway bar.  This 35mm bar will be something we offer in the future, but it is completely unrealistic to use without an additional heavy front sway bar to compliment it. 


We liked where we were going with the CNC production process over the blade-style so we continued... 


The RDS-05 beta bars have performed as expected and compliments the factory front bar well, but not overbearing like the 35mm S.O.B. prototype.  The RDS-05 has 3 adjustment positions ranging from 922 lbs/in on the outside position to 1439 lbs/in on the inside position.  These stiffness values include a loss factor of 20% for endlink and polyurethane deflection.  Safety testing performed on the RDS-05 includes a stress analysis using SAE standards.  For track enthusiasts, keep an eye out for our front bar coming soon.  


RDS-05 Benefits:
   Reduces body roll
   Tighten cornering abilities
   Increases traction on cornering
   Better vehicle control
   Improves dynamic weight distribution

For more information, check out the RDS-05 Rear Anti-Roll Bar product page.

The RDS-05 fits the 2007-2009 and 2010-2013 Mazdaspeed 3 models.  We are currently accepting local Mazda 3 models for test fitting.  Please contact us if you are interested!  (Central Florida)

Article by Cullen 

Posted on June 21, 2013 .