We all love our 90’s Z cars. When first introduced, Z32 had very respectable handling characteristics compared to other vehicles in its class. Thankfully, a lot of aftermarket suspension upgrades have been released since then to further improve those qualities and make the platform competitive with modern performance cars. Most owners go with an entry level coilover kit and an aftermarket set of control arms to correct suspension geometry after ride height reduction. That setup is usually sufficient to make some radical changes to the way your Z32 takes corners. Those of us who have higher demands from our vehicles also choose to upgrade sway bars and bushings (subframe, control arms and sway bars).
While all those bushings are available from aftermarket companies, one area of our vehicles was not upgraded correctly. Factory Z32 sway bar bushings are made of soft rubber. They do their job fine when new and probably suffice if you have mostly factory suspension car which you don’t really demand much of. Front bushings are held in place by a sheet metal bracket and an elevated square-shaped protrusion that is stamped into a tension rod mount. That protrusion easily compresses the rubber bushing and reduces lateral play.
 
That all works fine until you decide to upgrade your front sway bar bushings to aftermarket polyurethane counterparts. Polyurethane is multiple times firmer than factory rubber and is not designed to be compressed too much. When you try installing front polyurethane sway bar bushings on an elevated square stamped in tension rod mounting plate, you compress your bushing in a manner that it is not designed for. That causes bushing to distort, lose its shape, crack and eventually tear. But wait, there is more… Most aftermarket sway bars are advertised as “28mm front and “21mm rear”. That may be true in case of rear sway bars, but front aftermarket sway bars are NOT 28mm (see picture of red 28mm bushing over front aftermarket sway bar). When you try installing a supplied 28mm polyurethane bushing on a sway bar that is NOT 28mm and also compress it by installing it on a stock square shaped stamped protrusion, you are placing hundreds of pounds of pressure on that bushing in its resting state. As a result, you have a distorted bushing, a bushing that wears prematurely causing it to fail, excessive drag on your front sway bar as well as binding in severe cases and just an all-around improper suspension function. On top of that, sheet metal mounting bracket that come with bushings have elongated holes for mounting which makes it difficult to set the sway bar perfectly perpendicular to centerline of your car. Please refer to images of front sway bar bushings installed on NISSAN Z32 300ZX with a very popular sway bar upgrade. We have confirmed this issue with at least five Z32 owners and also a popular vendor.
 
However, Polar Engineering is not here to complain. We are here to offer solutions! 
Introducing our NISSAN Z32 300ZX Billet Sway Bar Mounting Bracket Kit with greasable polyurethane bushings.
 
-Bushing kit is NOT universal and was designed specifically for NISSAN Z32 300ZX. Mounting brackets have correct mounting hole spacing in front and in the back to perfectly mount in Z32 frame. Without any guess work, all four mounting brackets install your sway bars perfectly perpendicular to centerline of your Z making cornering dynamics identical in either direction. 
 
-To address the issue with excessive compression of front polyurethane bushings, Polar Engineering kit includes a thin mounting adapter that elevates your front bushing and provides a flat surface for it to be installed onto correctly without any compression.
 
-All bracket bodies of this kit (6 parts in total) are machined out of a solid piece of 6061-T6 aircraft grade aluminum for superior strength, low weight, and corrosion resistance. These brackets are not universal in application and have been designed specifically for the NISSAN Z32 300ZX platform. Five prototypes later, we have developed a perfect sway bar mounting bracket set that is designed for polyurethane greasable bushings.
 
-The kit comes with a set of polyurethane bushings correctly matched to your choice of sway bars. We have selected Prothane polyurethane bushings, one of the best greasable bushings available on the market to be included in our sway bar mount kits. We worked to find the perfect size of bushings for most sway bar brands available for Z32 platform for you to choose from. Once installed, they will eliminate any binding/noise that was caused by improperly sized bushings. Many polyurethane bushings on the market range in 40a-60a durometer scale. Prothane polyurethane bushings are rated at 70a (harder) and will give your sway bar setup a firm grip, while at the same time eliminating sway bar binding. The bushings are also greasable. Once greased and installed, additional grease can be injected into the bushing using a grease gun via a stainless steel grease fitting. You will no longer need to disassemble any component of your suspension to grease your sway bar bushings. Prothane bushings are designed and manufactured in California, USA.
 
-A lot of similar kits come with inadequate hardware. Many kits include stainless steel bolts to mount the bracket to the subframe. Stainless steel hardware is rated at 40,000psi tensile strength, which is only about 2.5 grade. Automotive suspensions require hardware rated 8.8-grade and above. Stainless steel hardware cannot be used in suspension components because it snaps easily. Polar Engineering kits come with 10.9-grade hardware that matches Japanese automotive standards. Steel bolts are also flanged, which distributes load evenly and eliminates the need for additional washers. The bolts are also coated to provide superior corrosion resistance even in wet environments.
 
-Stainless greasable fittings will allow you to inject additional grease (if necessary) into the bushing without the need of disassembly. The fitting is made of stainless steel for corrosion resistance and has an internal check valve that will keep grease from pouring back out.
 
-Additionally, Polar Engineering is first on the market to offer a Buna-N O-ring in the assembly designed to make a firm seal between grease fitting, bracket body, and the bushing. Other manufacturers do not have an O-ring designed into their kits which causes grease to be forced between the sway bar bracket and a polyurethane bushing. That causes slippage and excessive lateral travel of your sway bar. You will not have such issues with Polar Engineering kit.
 
-The kit comes with a packet of water-resistant polyurethane bushing grease that needs to be used during installation. The grease is very durable and will allow your sway bar to move in an unrestricted manner without any noise for very long periods of time.
 
-All billet aluminum parts in our kit are offered in “as machined” finish which we find to look beautiful. We have gone ahead and clear coated our mounting brackets in pictures to preserve that finish and eliminate oxidation. You will have an option to do the same, or let us know if you would like your set powder coated before shipping.