DIY Network

Suspension-Dampening Controller: Front Shock-Servo Installation From "Tricked Out" episode DTRK-205

	The project car: a 2003 Ford Focus SVT.
	The EDFC control unit lets you adjust the stiffness of your suspension system to fit the driving conditions or your personal preferences.
	Powered by remote control, the four independent servo units can turn the adjuster screws at the tops of each strut assembliy to customize shock stiffness.
	Media Watch the Video

NOTE: Images on this page may be enlarged for enhanced viewing simply by clicking on them.

In this episode of Tricked Out, host Andrew Totolos installs a remote suspension dampening controller to upgrade the coil-over suspension on a Ford Focus SVT. This system, also known as EDFC (Electronic Damping Force Controller), makes it possible to control the feel of the car's ride by pushing buttons from the driver's seat. Small servo motors installed at each shock absorber respond to commands from the dash-mounted control module--allowing the driver to make precise suspension adjustments on the fly. Since the damping force can be controlled with ease to meet different situations, the driver can enjoy variations in the suspension setting from hard performance-settings to soft comfort and anywhere in between. This episode is a follow-up to episode 204 in which the suspension was upgraded with coil-over suspension and performance struts.

In this first segment, Andrew explains the benefits of the EDFC, discusses suspension adjustments and installs the EDFC adjustor modules (servo motors) on the strut assemblies.

Materials used in this project:

In addition to standard auto-mechanic's tools (wrenches, ratchets, extenders, screwdrivers, nut-drivers, torque wrench, etc.), tools and materials used in this episode include:

EDFC kit
Allen wrench
8mm spanner wrench, from kit
Rubbing alcohol and towels
12-volt tester
Fuses and taps
Crimpers
Grabber tool
Panel removal tool
Industrial strength hook-and-loop tape
Electrical tape
Wire ties

Important: Included in this summary are the steps in this automotive procedure as shown in the episode. These steps are general guidelines that are applicable to most similar vehicles. With any particular vehicle, there may be procedures, specifications, settings, tolerances, components, etc. that are specific to that vehicle. There are also variations according to the type and brand of upgrade-kit you select. Always consult your vehicle's service manual when undertaking significant automotive repairs, and read and follow the manufacturer's directions and precautions that come with your kit or replacement parts.

Safety Alert: As a standard safety precaution, always disconnect the vehicle's negative battery cable before you begin work on any electrical or mechanical components.

advertisement

The Project Car: Ford Focus SVT

In all matters of performance the Ford Focus SVT focus outperforms its popular ZX3 sibling. But even though the SVT suspension is lower and firmer than the ZX3 model, there's room for improvement. This 2003 SVT already sports a hot euro package in bright yellow and a spiced-up exterior with custom airbrushed vinyl graphics. Behind the 17" lightweight alloys wheels, factory 4-wheel disc brakes clamp down on cross drilled rotors with street performance pads.

Under the hood, the cold-air intake feeds the Focus's dual-stage intake manifold, and an upgraded coil pack and plugs provide a hot spark. Inside, factory leather bucket seats and an upgraded short throw shifter.

Previous Mods: Coilover Suspension

Earlier we replaced the factory SVT suspension with a fully-adjustable damper kit (figures A and B) that will hold tight to curves and provide the adjustability to go from street to track to show with minor adjustments. The new suspension lowers the car a bit while maintaining stock suspension travel, and the stiffer springs eliminate a lot of the SVT's body-roll. Like most coil-over suspension packages, the stiffness of the dampers is adjustable so you can set it soft for cruising or hard for a track event. But since adjustment requires popping the hood, and even pulling out some interior panels in the back, to change the settings for each shock individually, a lot of people simply set the dampening somewhere in the middle and live with it. But we take the upgrade a step further. In this project we install a remote system that allows driver adjustment to the stiffness of the suspension right from the driver's seat.

Figure A

Figure B

	Figure C
	Figure D

EDFC Kit

The EDFC kit is made by the same company that made the coil-suspension system, and is made to fit perfectly with that system. The kit comes with almost everything you need for the installation (figure C). When you open the kit, you'll find a servo motor for each damper and the control unit, plus wiring and brackets. You'll also want to grab some alcohol and towels to clean the dash. For the wiring, you'll need a 12-volt multi-meter to locate the proper wiring points, fuses, fuse taps and crimpers to hook up the electronics. A wire grabber tool and panel removal tool will help with running the wiring around the car. For the most part, typical shop tools will handle the rest.

So how does the system work? Essentially, a shock absorber's job is to dissipate the energy absorbed by the springs. They do this by forcing oil through small holes inside the shock body. The smaller the hole, the stiffer the shock. On an adjustable shock, the hole size is variable. Most designs are adjusted by turning a small adjuster knob on the top of the piston shaft. Our EDFC motors mount on top of the damper (figure D) and do the turning for you. Installing the motors is fairly simple. We begin with the front driver's side shock.

DIY Difficulty Rating for This Project: We gave this a difficulty rating of 3 on a 5-point intermediate-level scale. Installing the servos and control module is easy. The trickiest part of the project is running the wiring from each shock to the dash control-unit.

Servo Module Installation

• Begin with the front driver's side. An 8mm spanner-wrench from the kit will help you remove the manual adjuster click assembly (figure E).

• Then use an Allen wrench to remove the black adjustment screw (figure F).

  Figure E

  Figure F

  
  

• Apply a bit of the grease from the kit to the new gold-colored adjustment screw, and thread it into the piston shaft (figure G) until it's flush with the top.

• Note that, on the Focus, the front and rear piston shafts are different sizes (figure H), so match the appropriate motor to the front shaft.

  Figure G

  Figure H

  
  

• Next, apply thread locker to the piston shaft threads, slide the Allen-head tip of the motor into the adjustment screw (figure I), and start threading the motor onto the shaft.

• Since the threads inside and outside the piston shaft are a different pitch, you'll need to "walk" the adjustment screw down as you tighten the motor. Hold the motor in place and turn the slotted screw on top of the motor (figure J) three full turns clockwise. Then gently screw the motor onto the piston shaft until it stops.

  Figure I

  Figure J

  
  

• Turn the top screw clockwise for two more revolutions and finish by turning the motor until it is hand-tight (figure K).

• Once the motor is in place, you'll want to make sure that the adjustment screw is positioned correctly by turning the top screw one revolution in both directions and then back to center.

• Once the positioning is correct, pop on the dust-cover (figure L) and the driver's side installation is complete.

  Figure K

  Figure L

  
  

  The project car: a 2003 Ford Focus SVT.

Important: These servo motors extend up higher than the tops of the existing adjuster knobs on the struts, so hood clearance may be an issue on some vehicles. The ones in this kit fit fine on our project car, but be certain that the fit will work on your vehicle before you begin this installation.

The article that follows details how Andrew installs the rear servo motors, the control unit in passenger compartment and runs the wiring for the system.

RESOURCES :

Sport Compact Bolt-On Performance Guide: Import Cars (Sport Compact Bolt-On Performance Guides)
Author: Joe Pettitt
Order this book from Amazon.com.
Voyageur Press (October 2000)
ISBN: 1884089526

TEIN USA, Inc.
Website: www.tein.com