Progress Coilovers Honda Civic / Civic Si (06-11) Series I

Here is some help SELECTING YOUR SPRING RATE combination. All rates are front/rear:

STREET-PERFORMANCE

• FRONT HEAVY SETUPS (350/250, 450/350 etc.)
• Good for Daily Drivers, poor weather and road conditions because these setups do not upset the ride on the highway and during cornering. The softer rear suspension tracks nicely and rides better because it is more compliant. These calibrations ride well on uneven road conditions if set up at a reasonable ride height around 1.0” to 1.5” less than OEM (12.5”). Expect a dramatic improvement in handling capability and steering response. These setups will still have some mild understeer, less than OEM but still easy and forgiving to drive every day and in all weather conditions. This is the choice for sport-tuned Daily Drivers.

STREET-SPORT

• SQUARE SETUPS (350/350, 450/450 etc.)
• These setups are a compromise between ride quality and all-out handling. Some impact on ride quality makes for less understeer and faster vehicle response. The stiffer front springs also help prevent bottoming out. This combination is stiffer  and NOT recommended for true daily drivers on poor roads, or drivers rolling a lot of commuter miles. Good for “fun cars” driven by more experienced drivers.

AUTOCROSS-TRACK & DRAG SPECIFIC

• REAR HEAVY SETUPS (350/450, 450/550, 450/650 etc.)
• These setups are much more aggressive. This calibration has more grip, and is intended for use with “track only” alignment settings and UHP sticky tires. If ride quality is a concern, don’t go here because the stiffer springs make for an uncomfortable (and choppy) highway ride. This is a more balanced and LESS FORGIVING setup intended for enthusiast TRACK days and AUTOCROSS events. These combinations will also launch well for mild drag applications on DOT tires. Expect a HUGE improvement in handling capability. This would also be a great low-budget setup for new (road racing) drivers going to a (track) DRIVING SCHOOL or TRACK events.
• These setups have faster chassis response, are less forgiving, and offer MAX GRIP in most cornering situations. The chassis balance will be very close to ideal, having minimal understeer with “track-only” alignment settings and real UHP tires. This is a BIG compromise in ride quality and will require more DRIVING SKILL to drive at the limit (on the track please!) NOT RECOMMENDED for wet/snow/poor weather and road conditions.

FRONT SPRINGS 550# and above, 550/550, 550/650 etc.

• Recommended for TRACK ONLY vehicles equipped with a front end splitter. The extra spring rate helps put the downforce to good use getting more from bite without excessive bottoming. Also can be used for street cars running super-wide wheels & tires and very low ride heights. At this point, you should know you are signing up for a HUGE compromises and a very stiff setup!