Chassis Electronics Heeltoe Explains

Tein’s EDFC: What Is It, Why Get It, & How To Order It!

TEIN (rhyms like “vein”) is one of the foremost suspension suppliers for the aftermarket industry. With a wide array of coilover damper choices to suit all kinds of cars in all kinds of uses, there is almost a Tein kit for anyone. But one of their most innovative items is the  EDFC , or Electronic Dampening Force Controller. This simple electronic controller and motor package is designed to make adjusting your TEIN suspension kit’s ride and handling settings as simple as, well, doing nothing! We’ll explain…

What is the EDFC and why would you want it?

The EDFC is a kit that can be used with various TEIN suspension kits (most any kit which has the adjustable knob on the top to allow for you to adjust the firmness of the suspension) to adjust the firmness from inside the car using a cool electronic controller.

“Wow how cool!” most people exclaim upon hearing this. But the next comment is usually “but I don’t change my settings much. If i just ‘set it and forget it’ why would I get this?” Here is Heeltoe’s take on it…

Yes, many people will set their suspension firmness once and then leave it alone. So if you don’t see the inherent value here, we understand. But consider that the reason they are not changing it around is that doing so is a pain in the ass. If it were as easy as pushing a little button, we think more people would adjust their suspension settings more often to suit their mood and needs at the time. Not all roads are created equal, nor are all cars or drivers. The EDFC allows people to take control over how their car is riding and handling over different surfaces and will allow them to get better overall value out of their suspension investment.

The Stuff You Need

First, you need a Tein suspension kit which is EDFC compatible. We try to list the EDFC parts needed under compatible TEIN damper kits, but if you are not sure if yours is or not, please contact us for help

Second, you need an EDFC controller kit. As of this writing, the options are the EDFC II, EDFC Active, and EDFC Active Pro.

  • EDFC II: A 1/4 DIN unit that allows adjustment of the front and rear suspension firmness from the driver’s seat with a push of a button. Change settings in 16 or 32 increments for fine damper control with up to 3 memory settings.
  • EDFC Active: With the use of an optional GPS sensor, this more modern unit will actively adjust firmer or softer based on the vehicle speed and acceleration. Plus, easier to install with partial wireless connectivity.
  • EDFC Active Pro: The full capability of this kit allows the driver to program the suspension to adjust each corner of the car individually to suit different g-loads, accelerating, decelerating, or cornering. It also will target varying speeds as well as offering auxiliary inputs

Third, you need an EDFC motor kit. There are various motor kits available and they are always selected based on the damper-shaft size. We try to list the EDFC parts needed under compatible TEIN damper kits, but if you are not sure what motor kit you need, please contact us for help.

There’s some Optional Stuff

The one main optional thing everyone would think about is the Anti-Tangle Kit. This is only needed for cars with STRUT suspensions. So, you wanna know the difference. This article will help you understand the difference between shocks and struts.

The EDFC Active GPS kit is needed in conjunction with the EDFC Active and EDFC Active Pro if you want to utilize the “Active” functions of those controllers.

A Brief History Of the EDFC

TEIN first released the EDFC in 2002 and such as system was largely unheard of in the aftermarket. The kit consisted of a two-part package. There was a controller kit and a motor kit. The motors were designed to replace the adjusting knobs at the top of each damper, and were hard wired with supplied harnesses to a central controller that could be mounted to the dash or wherever.

Original Silver EDFC in it's display-box.

This is the very first unit offered, it was silver in color and featured front and rear controls for individual adjustment. Another neat feature was that while the suspension kits were normally adjusted to 16 points with the hand adjustment, fine motor control allowed the dampers to be adjusted to 32 points, offering finer tunability.

In 2006, the EDFC got an update. The silver case was replaced with a black one…

Black gen 2 EDFC case

This more detailed image shows that the EDFC also offered up three memory settings. Our suggestion to customers was always that you could have a “Commute” setting, a “Fun” setting, and a “Mother-in-law” setting. Also, all EDFCs had been backlit with a green light.

More importantly, TEIN also changed the motors and harnesses. The motor on the left was the original motor, and the smaller one on the right was the newly released one.

Teein EDFC motors compared

These changes were hugely welcome, as the large motors made the installation in tight spaces a bit difficult. With the smaller motors, it would now be possible for the motors to be installed on the dampers before they are installed in the car. It probably would seem a lot more of a benefit if you’d done the job a few times in various cars. We definitely liked it.

Furthermore, the plugs on the harnesses were all smaller as well. Fishing EDFC wires through the interior is no harder than running stereo wires…but honestly any help in making things smaller is a definite improvement.

The most recent version of the standard EDFC is the EDFC II.

Tein EDFC II Controller

The EDFC II is functionally the same as its predecessors but it is aesthetically it is stepped up with LED lighting.

Sadly, the EDFC II was discontinued in 2020.

But the EDFC Active…Oh So Advanced

When the EDFC Active was released the whole EDFC concept seemed thrust into the 21st century.

EDFC Active from TEIN, with dimensions.

The features here are numerous, and so we are going to refer you to our EDFC Active product page for more details, but here are some bullet points:

  • Wireless Control: Instead of running wires from each motor to the controller, the front and rear motor pairs wire to shared wireless modules that communicate with the controller. So the system is not completely wireless, but installers no longer need to fish through the firewall or the interior.
  • Optional GPS kit allows active functions: With an options GPS kit, the EDFC Active can automatically adjust with speed or g-force (accelerating or decelerating). You can program the EDFC Active to vary the front/rear dampening balance as you are speeding up or slowing down to set positions at varying speeds. That’s awesome!
  • Variable color display: You can change it to match your interior color.

Those features are super awesome. And the EDFC Active uses the exact same motors as the EDFC II.

And then TEIN got really bonkers with the EDFC Active Pro, in which the ante is raised even further. With varying speeds and g-loads, the driver can now program the dampening force to adjust at each corner of the car., and it can do this based on lateral g-forces! So it can firm up the outside wheels in a turn, and even have the rear firm up a little more if, say, more over-steer is needed.

But then, it can be adjusted differently if the corner is a faster or slower one! OMG, there is so much capability with this unit. Truly innovative!

That’s a lot of info on the EDFC

But with a purchase like this, sometimes it’s best to chat over it. Feel free to call for a consult at any time!

Chassis Heeltoe Explains

Tech: What’s the Spring Rate of my Torsion Bars? #torsionbarhondas Content Inside!

1984-87 Honda Civic/CRX and 1986-89 Acura Integra models came with a unique torsion-bar front suspension. Because of the non-conventional nature of a torsion bar as compared to a coil spring, people at times become lost on what various bars’ diameters equate to what would be conventional spring rates. This is an important figure for determining the balance of the car and for tuning the dampers.

Between the various diameters and lengths of bars available, we were a bit lost on it ourselves, but a little poking around led us to Sway-Away’s website. As some may know, Sway-Away is one of the foremost torsion-bar producers having even produced bars for said Hondas at one point in history. We knew this convenient calculator was something we could trust!

On the page there you will find the science behind the torsion bar wheel rate calculation. You’ll also see that the effective wheel rate is the same as the spring rate taken at the end of the control arm, or what is actually the lever on which the wheel’s movement acts.

You can play with it all you like, but we have taken the liberty of making a quick chart for fast approximate reference. Some of our dimensions are approximate but the spring rates should be accurate within about 5-10% and that’s really pretty good for our purposes.


  • LCA stands for “lower control arm.” Since people tune both Integras and Civic/CRX models, and sometimes Civic/CRX people put the longer Integra lower arms in their car to increase camber, we include both here. We approximate a 13.5″ length on the Civic/CRX and 14.5″ on the Integra, from the center of the torsion bar to the end of the ball joint.
  • All rates are in pounds per inch of travel (lb/in), but we have a lb/in to kgf/mm charge just below.
  • Not all these torsion bar diameters are actually available, but we are listing them anyway since any of them technically could be made or exist.
  • The bar length will impact the wheel rate, too. The 24.3″ bar is the length of CRX and many Civic bars. Some Civics have a bar that is about 1/3″ shorter, but the rate change is fairly minor so we have omitted it to keep the chart simpler. The Mugen bars that were made long ago were shorter than the Civic/CRX ones, with an overall length of just under 22.5″. These would give the highest rate per diameter, and being the more compact bar would have the least weight (no surprise that the Mugen bar would be the ideal for performance yielding the most rate-per-weight!).

We work on Japanese cars at Heeltoe here, and oftentimes it becomes necessary to work in both lbs/in and kgf/mm (that’s kilogram of force per millimeter). They are different ways of saying the same thing about a spring’s rate, but we’ve offered this handy conversion chart for you to know the equivalents. This info is pulled from’s Standardized Spring chart.


Please feel free to leave any commentary or calls for correction below! And never forget that Heeltoe is always in your corner, aiming to provide the best and most accurate info we can to help you tune your car!