Suspension Upgrades

About once a week I get e-mailed with the question, "I want to upgrade my suspension. What do you recommend?"

So for what it is worth, here are my thoughts on suspension upgrades.

First off, keep in the mind that right off the showroom floor the suspension in the Miata is pretty damn good. The engineers at Mazda worked long and hard to fine-tune the suspension. And that was just for the 90 model year. Every year since, they have tweaked it here and tweaked it there to make little refinements.

The point Im trying to make it that it is easier to mess-up the suspension in the Miata than it is to improve it. So before you begin, keep in mind that most "improvements" will result in a stiffer ride. The stiffer ride may be fine on the track, but is probably not what you what in a daily commuter car. I remember talking to a guy about four years ago who "up-graded" the suspension (springs and shocks) on his daily commuter Miata. He lasted about three weeks before he changed it back to the way it had been before. So think twice before you start down the suspension upgrade path.

Sway Bars and Springs and Shocks Oh My!

There are basically three things you can change, the front and rear sway bars, the springs and the shock absorbers.

Upgrading the sway bars are probably the safest, easiest and cheapest improvement you can make. Sway bars affect how the Miata handles on corners. They keep the car from leaning on the curves and help to keep the wheels flat on the road. When I say safest, I mean that changing the sway bars is most likely to give you better handling at corners and on curves without mucking up and making the general ride of the car too stiff. In fact it is such a good idea that over the years Mazda has increased the size of the stock sway bars to improve the handling. So as a result, adding aftermarket sway bars to the Miata will have a greater effect on the earlier model years than in the more recent models. Jackson Racing and Racing Beat as well as some others make some very good sway bars at reasonable prices.

Springs can do two things for you; besides stiffen the ride, they are also lower the car. Lowing the car lowers the center of gravity. This has the effective of helping the Miata hug the corners better. However, lowering the Miata also has a dark side, called "speed bumps." The stock Miata is already pretty low, lowering it an inch or so will have a big effect on your Miata going over speed bumps and going up and down driveways. Racing Beat, Eibach and a few others all make good springs that will lower and stiffen the ride at the same time.

Shock Absorbers

If you decide to change out your shock absorbers, there are a lot to choose from. There are the OEM shocks and KYB makes a shock that is just like the OEM. Then there are "high performance" shocks that will stiffen the ride from companies like KYB GR-2, Bilstein and Tokiko HP to name a few. Then there are also the adjustable shocks. The Tokico Illumina 5-way adjustable shocks and the KYB AGX 8-way adjustable shocks. The adjustable shocks allow you to "adjust" the amount of pressure used to dampen the ride. While these can be expensive, adjustable shock can be a good compromise to get the smooth Sunday in the country drive and then with a little simple adjustment to each shock you have stiffen your suspension for a Saturday afternoon of Autocrossing.

Bottom Line

Well, after all that, I'm not telling you NOT to try to improve your suspension. But, you should be aware of what you are getting into before you spend a couple hundred dollars on the "improvements."  Because while you my be making it a better car for racing, you may also be turning you Miata into a car that just isn't as fun to drive as it use to be. And afterall, isn't that why you bought it in the first place.  

Good Luck