Flyin' Miata : Chassis : Suspension components : Flyin` Miata AFCO suspension

The Targa Newfoundland is a 7 day, 1400 mile tarmac rally. The competitive stages range from extremely tight and twisty to flowing and open, with surfaces that range from smooth to battered. Since the competitors don`t get a chance to run the stages before the race, the cars must not only be nimble but also have to be without any evil habits. Sounds tough, doesn`t it? It is. But a car that can handle the Targa is also a fantastic road and track car. So when we started to build a Targa car, we set out to built the perfect Targa setup - the first full Miata suspension built to Flyin` Miata`s specifications. You can read more about the car and the 8-month development process at Targamiata.com.

Our goal was a suspension that not only had performance on the track, but had as much travel as possible in order to absorb the biggest bumps without upsetting the car. We achieved nearly 7" of travel in the rear without the spring going loose - dramatically more than seen in the Ohlins DFV. We let the suspension compress almost to the point where the control arms begin to hit the subframe, and the rear wheels can droop down to 16.5" from the fender lip without the spring going loose. Yes, it does mean you have to jack the car pretty high to change a wheel!

Just because the suspension was designed with long travel and rough surfaces doesn`t mean that it`s not good for track cars, though. We tested on the track as well as the street. It will happily run at low ride heights - and a car fitted with the AFCO suspension has the Miata lap record at our local track, despite a 100 hp deficit over most of the others that have tried. In fact, at our 2008 Open House, two of the three fastest Miatas were running AFCOs, as were the two fastest naturally aspirated cars.

Over the course of development, we changed body lengths, shaft lengths, spring lengths, spring rates, shock valving, bump stops, upper mounts and even the lower bearing design. We ran comparison tests with other suspension setups on the track, the street and the shock dyno. We spent a lot of time tuning the high-speed compression to absorb small bumps and sharp edges. The result rides as well as the best on the market and is fast enough to outrun a Spec Miata on the track. In fact, a Miata with AFCO suspension won the SCCA F Production national championships in 2006 and 2007, and then it won E Production in 2008. That`s three consecutive national championships.

The suspension is built in the US by AFCO, a company that deals almost exclusively in race shocks. We worked with them closely on the specifications of every aspect of the suspension. Their experience in keeping wheels planted over rough surfaces is what lends these shocks such great traction and a smooth ride.

Both compression and rebound are independently adjustable over a wide range so you can fine-tune the suspension for your car`s weight and chassis setup. There are 22 settings for compression and 32 for rebound, and the adjusters have a nice firm detent so you don`t have trouble repeating your settings.

Internally, they`re built with very low friction and feature deflective disc design. This type of internal design is not only more consistent to manufacture than the usual spring, but it also responds better to small movements and low velocity and offers more options for damping curves. Every shock - identified with a serial number - is tested on a shock dyno before shipping to make sure it behaves the way it`s supposed to. The dyno printouts are included as well as stored at AFCO, so the shock can be retested in the future to check for wear.

The bodies are anodized aluminum for light weight, good heat control and long life. The shocks can be rebuilt and revalved if required, although even under the harshest use we don`t expect a rebuild to be necessary for 5 years. The springs are wound from chrome silicon wire, heat treated twice and carry a lifetime warranty. The standard rates are 450 lb/in front and 300 lb/in rear, but we can supply a wide range of alternatives. There is a $10 surcharge for custom spring rates. You can also use any 2.5" race spring if you already have a stash of your own. If you want to run extreme rates we can also have the shocks custom-valved for your needs, although the stock valving will handle up to 750 lb/in in the front.

So what`s the result? A suspension that will take big hits in its stride while offering a high level of body control. There`s a spot in our local track where you need to brake from the fastest point on the track to the slowest. If you`re going to brake late, you have to wait until you get past a short kink, turn in and then lay hard on the brakes and run one side of the car over a ridged kerb. As you can imagine, this can be very exciting. The AFCO suspension is astoundingly stable under this sort of abuse, far more so than any other suspension we tried. The long travel means that the rear wheels are firmly pressed into the ground while the fronts stay off the bumpstops. Mid-corner bumps - big or small - don`t bother the car at all. In fact, at one of our test tracks, the fastest corner is very bumpy and the surface varies from asphalt to concrete to steel. In most cars, you just hang on as you get thrown around. With this suspension, the car never gets upset. It just eats up the road. During the Targa Newfoundland, we hit a sharp speed bump at full throttle at 80 mph, and the car didn`t get upset at all.

The shock is a twin-tube design. Some of our competitors (who only sell monotubes) are quite wound up about this. Both monotubes and twin-tubes have their advantages and disadvantages, and we sell both depending on the application. But the fact of the matter is that the implementation is more important than the underlying technology. These shocks have won three national road-racing championships, survived the brutal Targa Newfoundland, taken numerous FTDs at local autocrosses and have taken the lap record at our local track. With that sort of record, it`s fair to say they`re proven.

One of our customers replaced his Koni/Ground Control suspension with a set of AFCOs with custom spring rates. The result? He took 6.2 seconds off his lap time at Willow Springs, a track he`s been driving for almost 20 years. That`s huge. The only other change made to the car was a slightly larger front sway bar.

See it in action! This video shows an AFCO-equipped car hammering into berms on our local track. The car was completely composed and never bottomed out. Even the turbocharged Westfield being used as a camera car couldn`t keep up. 2.31 MB, requires DivX to play.

It`s our flagship suspension. We think it`s perfect for the Targa. And the real world.

For 1990-05 Miatas.

Shock dyno graphs
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