Once again, the passenger side bushing is easy to install.
Once bolted in, the passenger bushing was ready to go.
The driver’s side bushing was another story. This took a lot of time to get the more complicated-shaped bushing around the bracket and the bracket around the bushing, all in a very tight space. Once installed, FSE Irvine technicians marked the bolts with paint for quick reference if the bolts loosened up over time. This is a good step that makes checking over the car much easier than constantly throwing a wrench on each bolt to check to see if they loosened up.
Once the steering rack bushings were in, we reinstalled the swaybar and new swaybar end links.
With our new, stiffer SuperPro steering rack bushings and stiffer front swaybar installed, we were ready to re-align the car and test it out.
On the street and in the canyons, the stiffer front swaybar greatly reduced front body roll and improved the balance of the car with the much wider 255-width front Continental Extremecontact Force tires and 17×9.5 Titan-7 T-D6 wheels.
The swaybar isn’t overly stiff and does not hurt ride quality over uneven and bumpy roads. It also does not eliminate body roll completely, which is still present, but it is a much-needed improvement over the stock bar. Our car is equipped with softly-sprung Ohlins coilovers that are very much daily driver focused. We have plans to upgrade the suspension to improve performance further, without sacrificing ride quality or street ability in the near future, which should work out and pair well with this stiffer SuperPro front swaybar.
The swaybar endlink clunk and the steering rack movement when cornering are now completely gone, thanks to the new SuperPro bushings that hold the steering rack tightly in place. There is zero increase in NVH through the steering wheel from these bushings, which can be a negative result when installing solid or overly stiff steering rack bushings.
Overall, we are very happy with the performance of the stiffer SuperPro front swaybar and steering rack bushings. They solved the issues of our FD RX-7 and live up to their good reputation for improving performance without sacrificing refinement and comfort. We will be testing their control arm and suspension bushings in the near future because the rest of the rubber in our FD is 30 years old and likely just as bad as the steering rack bushings. Stay tuned.
3 comments
Looking forward to reading more articles as this project continues!
You are developing a responsive and engaging setup, whilst maintaining characteristics to make the car safe and pleasant to drive everyday. As much as I love factory backed GTE/GT3 cars, and wild race/hill climb builds, it is equally enjoyable to see a balanced, practical build like this. As always, fantastic content from everyone at MotoIQ.
Thank you for the feedback!
I am always really surprised by this kind of steering rack designed used on so many cars. It’s basically asking for eventual play because it’s ability to move side to side is not properly constrained. I have only seen a handful of cars that actually properly locate and constrain the rack with bolts directly into the subframe. I know that early 911’s do this while later ones have a similar setup to the RX-7. I am assuming that it’s an NVH issue.
It’s such a huge increase in steering precision and feel to have PU bushings in a steering rack. I think it’s probably one of the cheapest upgrades, and if you have the chance to do it to your vehicle, it’s an absolute must.