Armed with a strong background in vehicle dynamics and chassis design, we’ve spent months understanding the BRZ/FRS/86 chassis, testing different designs, collecting data, and measuring performance. With the help of the FT86Club community, we’ve developed a strut tower brace that works.
Our design requirements for this project were simple. The GrimmSpeed Strut Tower Brace must provide additional stiffness between the strut towers, enhancing stability and sharpening steering response. We began with testing both on the street and by statically flexing the chassis in the shop. Tweaking the chassis manually and using our FARO Arm to plot-critical points in CAD, we were able to identify the weak points in the system. What we found was interesting. The OEM triangulation bars actually function very well. So, while the allure of a beautiful 3-point brace was tempting, the data spoke loud and clear: a simple 2-point brace was the right solution. With that, we set out to create a clean, simple, and cost-effective solution. Using 3D scanned data from multiple vehicles, we were able to quantify the manufacturing tolerances and design our brace accordingly. What that means for you are a perfect fit and easy installation. 3D-printed prototypes helped speed the development cycle and allowed us to test a number of different bracket designs for fitment and aesthetics. One key design decision was to utilize a rigid, welded construction. The reasons for this are three-fold, but what it boils down to is the old standby, ‘Keep It Simple, Stupid. When the goal is to reduce compliance in the system, it’s not hard to understand why a solid form design is best.
End brackets are laser cut from 3/16" steel and precision CNC bent. These brackets were sized to provide maximum strength and stiffness without compromising thread engagement with the vehicle. Cross tubes are CNC laser cut to length from .125in-wall tubing. Mild steel, being both the viable material that is both economical as well as well-suited for the job, was an easy choice. Contrary to popular belief, mild steel offers greater stiffness than stainless steel and while stainless steel offers higher yield strength, in this particular application, we’re nowhere near those types of forces. The assemblies are all robotically welded in the same fixture for unbeatable accuracy and repeatability. Each finished brace is coated with a durable DuPont textured powder coating. The cherry on top, so to speak, is that we’ve laser-cut the GS logos from stainless steel, so you’re free to polish the coating off of it for a unique look without worry about rust.
Performance metrics, both quantitative and qualitative were carefully tracked through development and following production. In our slalom testing, peak deflection between the strut towers dropped from .180in to .030in, a decrease of 83.3%. Even more notable than the lowering of deflection was the substantial decrease in ‘noise’ within the data. You can truly feel this improvement the first time you leave your driveway after the install. Expect an immediate and noticeable decrease in NVH and a noticeable increase in sharpness and steering feel. The chart below shows strut tower deflection through a series of slalom turns before and after the installation of the GrimmSpeed Strut Tower Brace. What you see is that without the brace, the data shows a great deal of noise and unpredictable deflection, indicating an unsettled chassis. After installation of the brace, noise in the data is greatly decreased and behavior is much more predictable. With the brace installed, the chassis reacts as you would expect, cycling between tension and compression as the brace works to maintain stiffness between the strut towers through the slalom.
- Subaru BRZ (2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022)
- Scion FR-S (2013, 2014, 2015, 2016)
- Toyota GT-86 (2017, 2018, 2019, 2020, 2021)
- Toyota GR86 (2022+)
- Laser cut, CNC bent brackets ensure perfect fit
- Mild steel construction provides maximum stiffness
- Rigid design prevents unnecessary slop and tolerance stacking
- Durable DuPont powder coat
- Installation in minutes with only a single tool
In stock, non special order items can be returned within 30 days of the product arriving to your house or place of work.
Returns will NOT be accepted on Clearance Items, Final Sales, Special Orders, Opened, Installed, Incomplete, or Otherwise Used Products. In order to initiate a return, an RMA number must be requested and approved via e-mail.
All returns will be subject to a 20% restocking fee minus complete shipping cost (roundtrip).
Any processed orders that have not shipped will incur a 6% cancelation refund fee unless the product was not available to ship within a timely manner. No fee will be incurred if used as store credit.
For complete details on our return policy, please see our Help and FAQ link under HELPFUL INFO.
INTERNATIONAL DUTIES AND TAXES
All international orders outside of the USA are subject to duties and taxes per your countries jurisdiction and determined by customs.
Kami Speed serves the right to ship using an alternative method if we see it fit, in order to expedite shipping and reduce your rate depending on product value.