How's Your Damper Doin'?

How's Your Damper Doin'?

We all love our cars, and we all check the common maintenance points that we know extend the life of the motor. But when is the last time you checked your damper?

Miatas are 4-cylinder flat-plane crank engines. These types of engines are inherently prone to vibrations and unbalance. (If you want the deep engineering explanation about why this is, let us know—I'm more than happy to share!)

In short though, this type of engine creates a large amount of unwanted vibrations, and relies on an external damper to control them.

What happens if these vibrations go unchecked? Well, apart from being uncomfortable for the passengers, excessive vibrations can accelerate bearing wear, crack oil pump gears, damage crank shouts, and rob small amounts of HP.

The OEM solution is pretty simple. There's a lightweight center hub and a heavy pulley that are glued together with a ring of rubber. The weight of the pulley resists changes in direction, so it "dampens" any sharp vibration thrown it's way.

This is a good, cost-effective design. But there are two issue with this design.

The first issue is not a design fault, just a sad fact of life. Rubber doesn't age well. Just like all the other rubber parts that degrade and fail (gaskets, timing belts, soft tops, motor mounts) the rubber in the damper ages and at some point no longer does its job.

In some cases, it gets rock hard and no longer dampens. The pully just becomes a steel brick—which is better than nothing, as the mass alone has some dampening effect. But it's not ideal for engine health.

In other cases, such as the picture above, the rubber cracks, splits, and the outside of the damper will begin to separate. This appears to be more common on cars in a hot/dry climate.

The second issue with this design is that it's limited on how many frequencies it can handle. The primary frequency of vibration (the resident frequency that the motor creates) changes with RPM. For the OEM application, the engineers looked at what RPM the motor would be spending most of it's time at and designed a damper to hit that frequency.

If you're racing the car, or have modified the engine to hit higher RPMs than stock, you're most likely spending a lot of time outside of the RPM the OE damper was designed for. If you're like me, even my street car lives a lot of it's life at redline. :)

Enter the Fluidampr! This damper design solves both of the above issues. Instead of a static rubber ring, it uses a gel to dynamically change the dampening frequency as you run through the RPMS. It also mounts to the crankshaft more firmly to better handle the vibrations.

We have used these dampers for years and run them on everything from our crazy track monsters to our LMC autocross cars. They are made in USA and work for all long nose crank cars (1991.5-2005).

And we personally prefer these over the ATI dampers for their ease of install. In some select applications the ATI will be the correct choice, but 95% of the time we run the Fluidampr as our #1 choice.

And while this upgraded balancer is worth every penny, it is overkill for a street car that's not being driven hard. If your car is more of a classic cruiser, we do have the Mazda OEM dampers in stock as well, along with the hardware needed to install.

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