Project V8 RX-7: Part 15 – Major Suspension Overhaul with KW Suspension, SuperPro and Improved Racing Components


SuperPro’s steering rack bushings will replace our well worn 20 year old stock bushings.  A solidly mounted rack without play means steering inputs will be directly transferred to the wheels without slop and the driver will feel more positive feedback through the steering wheel.


Superpro steering rack bushings installed.


SuperPro makes a replacement but we didn’t bother changing our delrin rear differential bushings.  Although the solid rear differential bushings transmit a tremendous amount of noise and vibration to the chassis, removing the rear differential was more work than we were willing to do at the moment.  We have other plans for our rear differntial in the not too distant future.


As mentioned before, SuperPro makes an upgraded front swaybar for our FD however we are using a Speedway Engineering swaybar from Tripoint Engineering on a custom mounting bracket we made (the stock brackets are made of thin metal that deflect and bend from the forces subjected on them by upgraded swaybars).


Part IV: Alignment

With all our new components installed we took a trip over to West End Alignment to get it all set up correctly.


Darren adjusted the camber, toe and caster to settings we got from our suspension whisperer Mike Kojima…


If you’re curious what those were:

Camber 2.5 negative
Caster plus 7 or as much as possible
Toe 1/16″ out

Camber 1.7 negative
1/16″ toe in

We changed up a LOT of things in our big overhaul here but in real life we installed the Improved Racing toe links, trailing arms and strut brace first along with the SuperPro bushings and installed the KW’s a little way down the road.  As you could probably guess the road noise and harshness of the delrin bushings will not be missed and in our seat of the pants cannot tell any real difference in handling on the street.  We still hear a lot of drivetrain noise through the rear end reminding us we were too lazy to change ALL the bushings but that will be addressed soon enough.  The Improved Racing toe links fixed the rattle in the rear.  The KW’s made an improvement over Koni’s they replace most noticeably over uneven road surfaces.  Where the car used to feel skittish it seems much more surefooted now–able to suck up the bumps and dips better.  We haven’t had the car on a track yet and our tires still need an upgrade but overall driveability and roadholding is improved and we feel like we have more confidence laying into the throttle mid-corner than we did before without (as much) worry of snap oversteer.

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