In 1998 the aftermarket for upgraded suspension for the RX-7 was slim pickin’s in the USA. You could roll the dice and buy a set of dampers from the Japan with no tangible knowledge base regarding performance or reliability and run the risk of no ability to effect a repair or source spare parts if you have a problem….or you could buy domestic and pay through the nose for a hand built custom set from the likes of Penske or Koni. But there was a poor mans budget option…the Koni Yellow single adjustable shock. Want a little ride height adjustability? Ground Control offered some machined collars and spring seats that would work with the Koni Yellows and all for a relatively affordable price. So that is what I did…back in 1998.
Fast forward to 2010 where the aftermarket for dampers has grown substantially. So many more options are available. Add to this more experience to draw on not to mention the used market. With that in mind I decided it was time to step forward a few decades (the Koni’s Yellows are a 20 year old design) and upgrade the dampers on the car to something more advanced. The next question was how much to spend? There are a wide array of mid level performance dampers available for between $1000 and $2000 for a set of 4. These are typically mono-tube multi-adjustable dampers with ride height adjustability. The question of quality and reliability becomes an issue. Some market dampers that are simply rebadged versions from another manufacturer so it becomes quite difficult to determine what is decent. Until you step up to the next price bracket where the dampers start at $1000 per corner. These come from the likes of Penske, JRZ, and Koni. They are VERY expensive and really meant for full-on race cars. Was there anything in the middle? After some digging and reading I “found” dampers that appeared to fit my desired performance profile – not a compromise damper but one that could live on the street and yet give me the desired performance on the track.
Stance, a Japanese manufacturer, offers a multi-adjustable ride height adjustable damper with remote gas reservoirs and pillow ball upper mounts. The GR+3 had a respectable history and shared multiple common design aspects with the JRZ dampers right down to damper oil from the same manufacturer (or so they say). And the kicker…they were not as expensive as the other high end dampers above with a retail price range in the mid to low $3000 range for the set. As it turns out because Stance was looking to become a more attractive option for the RX7 market I was offered the opportunity to purchase a set of their high end dampers at a reduced price given that my car would be one of the first to use them on the track. So I plunked down my money and ordered a set with a few extras – aluminum bodies verses steel bodies, 10kg/cm rear rate springs versus the 12kg/cm they are normally packaged with, and a gas overpressure adjustment tool. I had them valved at the factory to match the lower rate springs in the rear. It took 6 months to get them but I believe it was worth the wait. As solid and nicely designed piece of equipment as I have seen. The pictures speak for themselves.
Installation of the dampers was as straightforward as installing any other damper but what required considerable forethought was where to mount the remote gas cylinders. The fronts could be mounted in the engine bay…somewhere and the rears in the hatch area bolted to the roll bar rear support legs. The issue being how to route the braided SS hose to that location AND how to physically get the cylinder they without disconnecting everything and having to refill the cylinders with nitrogen. The fronts proved to be fairly straight forward as I simply passed the cylinders by the front fender liner and mounted the cylinder on a custom made bracket attached to the headlight bucket rails above the radiator. The adjustments are easily accessible from the top by simply popping the hood.
The rears were an issue. Some have mounted the cylinders under the car to the rear subframe…ok but required laying on the ground and reaching under the car to make any adjustment. Not my speed at my age. The only way to plumb the cylinder and gas line to the hatch area was to break out the drill. So with 2 ½” hole saw bit in had I cut away. Intimidating but now that it’s done I have no regrets. Threading the cylinder and line through the hole I then bolted it to the legs of the roll bar. They look good through the rear hatch glass! I then used some large 3’ bulkhead penetration covers to cover the holes and help center the SS line and avoid any chafing on the rough edges of the hole.
While all the rear suspension was apart I decided to install a nice set of hiem joint rear sway bar end links. Not too hard but a couple of issues were encountered.
The next task was to set the ride height… a tweak here a tweak there and it was good enough to drive the car. However the final icing on the cake will be an alignment, corner balancing, final ride height adjustment, and some initial baseline damper settings from a knowledgeable race shop so I have a good starting point.
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This page last updated July 7, 2012