2006 to 2009 Honda Civic Si High Performance Aftermarket

Based on the eighth generation of the Honda Civic, the 2006 to 2009 Civic Si continues the legacy of the 5 previous Civic Si models offered in the US market. Drawing heavily from the discontinued Acura RSX Type S which was discontinued when Acura chose to change the focus of it's products and move more upscale, Honda utilized it's K-series engine (with some minor changes) that produced 197 hp as well as the six speed transaxle. Some say that the 2006 and newer Civic Si is a continuation of the Integra lineage from which the RSX was developed.

The new Civic Si has all the right stuff as standard equipment; six speed trans with limited slip diff, (all hot rods have 3 pedals!) 4 wheel disc brakes, independent suspension both front and rear, high-revving 197 hp K-series engine, good looks and 2 bodystyles available...2 door coupe and 4 door sedan.

Chassis designation are as follows:

2 door coupe is the FG

4 door sedan is the FA

Mechanically, the 2 door and 4 door versions of the Si are very similar and most aftermarket performance parts except cat back exhaust (4 door is longer) will fit both body styles.

How do you get 1.67 horsepower out of each cubic inch of displacement in the K20Z3 engine used in the 2006 2007 2008 2009 Honda Civic Si? Especially when it used to be quite an achievement to get 1.0 horsepower for each cubic inch back in the day? And do it with out the aid of supercharging or turbocharging? And get good fuel economy with very clean emissions?

i-VTEC, VTC and the modern ECU is the way.

i-VTEC is the engineering marvel that allows an engine to have 2 sets of cam profiles on the same camshaft, each developed for a certain part of the RPM operating range. So at lower RPMs, you have a sweet, smooth idling profile that makes good torque, low emissions, and good fuel economy. At higher RPMs, the ECU (Engine Control Unit or computer) will switch to the more aggressive and powerful cam profile to make crazy power like a race camshaft. It is like having your cake and eating it too! The ECU will control the switchover point as the RPMs change. On the K20Z3, this is done on both the intake and exhaust camshafts, unlike some other Honda and Acura engines with the VTEC feature which may only have this available on the intake camshaft.

In addition to the VTEC feature, the K20Z3 has VTC...Variable Timing Control on the intake camshaft. This VTC feature allows the ECU to optimize the cam timing of the intake camshaft as conditions dictate...think of dyno tuning your intake cam gear while you drive and you get the idea. Other features such as 4 valves per cylinder, high flowing cylinder head design and roller rockers (to reduce friction) all add to the amazing output of this K20Z3 engine.

The K20Z3 is a direct decendent of the K20A2 used in the Acura RSX Type S, however there are some small differences.

To keep that good running K20Z3 in it's sweet spot of the RPM range, Honda equipped all FG coupes and FA Sedan versions of the Si with the close ratio 6 speed transaxle, sorry no automatic (or is it auto tragic?) available in such great "driver's car"! Some say that real hot rods only come with 3 pedals.

Each of this generation of the Si are equipped with LSD...no not the drugs, Limited Slip Differential! This LSD unit helps to put the power to the pavement by transferring power to the front wheel that has traction when one of the front wheels starts to spin. Tire spin and smoke is cool, but it is not always fast...especially around corners. All the power of the K20Z3 is useless if you cannot use it! The LSD definitely helps this.

Many high performance enthusiasts will spend upwards of $1000 for a LSD for their modified cars, this generation of the Civic Si comes with it as standard equipment...you gotta love that!

2006 2007 2008 2009 Civic Si has a very good handling chassis to help you deal with the corners that you encounter on the "road of life". The FG/FA Civic Si has a MacPherson strut front suspension with a double wishbone rear suspension for better camber control which in turn helps to keep the tire contact patch working at maximum efficiency with the road surface. Ever heard of handling described like that? No cheap twist beam rear axle like many compact cars!

Even those who "live life a quarter mile at a time" will appreciate the handling prowess of this chassis and look forward to the next corner.

So how did Honda accomplish this?

Larger Anti-Sway bars on the Civic Si when compared to other trim levels of the Civic. Also, Honda added significantly stiffer spring rates matched to upgraded dampening to give a controlled, firm, high performance ride that loves to eat up the corners.

Also, the 2006 2007 2008 2009 Civic Si comes with 4 wheel disc brakes as standard equipment. 11.8 inch, ventilated front brakes with 10.8 solid rear discs stop the action should you be enjoying all the power of the K20Z3 engine!

Stock tire size is the very popular 215/45R17 which has many high performance and ultra high performance tires available in this size. The Civic Si can be ordered either with All Season tires or Summer tires.

If some is good, more is better and too much is just right!

As with any product, there are a series of compromises to tailor the traits of that product to a large audience so it will sell well. Cars are no different. While the 2006 2007 2008 2009 Civic Si is targeted at the performance enthusiast driver, not all enthusiasts will tolerate certain traits while others are willing to make sacrifices in the name of further improved power, handling, braking, functions, etc..we all like something a little different than the next person. That is why the automotive, high performance aftermarket exists, to cater to those who want to run faster, jump higher, and/or stand out from the crowd.

Some of the more popular high performance modifications for the 2006 2007 2008 2009 Honda Civic Si are lowering springs, Progress 22mm rear sway bar kit, Short Ram and Cold Air intake kits (K&N, Injen, AEM, Fujita), Cat-back exhausts (Vibrant, Magnaflow, DC Sports), "The Stiffy" Engine Torque Damper, brake upgrades and many more.

Gotta have the stance right. Lowering your Civic Si will not only improve its looks by eliminating the 4x4 look, but it will lower the center of gravity which improves handling. As most lowering springs have a higher spring rate than stock, this will also help to improve handling as well. Working hand-in-hand with this, an upgraded rear sway bar like the Progress 22mm kit will help to get your 2006 2007 2008 2009 Civic to rotate better in the corners and eliminate the "push" or "plowing" often associated with front wheel drive cars when corniering at or near the limit.

You have probably heard that any internal combustion engine is nothing more than an air pump and that the easiest way to increase efficiency is to improve the engine's breathing capabilities. Cold Air and Short Ram Intake kits are usually the first step taken. Relatively easy to install, these air intakes will provide a good bang-for-the-buck in terms of horsepower gained for the money spent. Improving things at the other end, a cat-back exhaust usually complements the cold air kit with a significant gain.

To make sure that none of this newfound power is being wasted, an Ingalls Stiffy Engine Torque Damper will control the unwanted motion of the engine/transaxle assembly on the stock rubber mounts so the energy is sent down the axles to turn the wheels, not spin the engine and trans on its mounts.

With increases in power and handling, upgrades to the braking system should be considered, especially if you are going to participate in some form of motorsports. High performance brake pads, not race pads should be used to not only increase braking power but also to endure higher temperatures. Race pads should not be used on a street car as they need lots of warm up to get them up to operating temps. Hawk Brake, EBC,and Performance Friction all offer high performance street pads as well as competition and race pads for various motorsports applications.

Additional brake upgrades such as stainless steel braided brake lines can improve pedal feel since they do not expand under pressure like the stock rubber lines will in hard use situations.

If you have already covered the basics mods listed above, you may want to consider this next group for more power, increased handling and improved street cred!

Race header, not for everyone and certainly not legal in many states, but this mod can free up power. Some headers like the Vibrant Street header comes with a metal core cat to keep you legal (check your local laws before ordering), while others eliminate the cat (for off-road purposes like racing only!). Some headers and some cat backs may not terminate at the same point in the exhaust system and thus not work together. This is one area to plan ahead before ordering so you end up with compatible parts.

Next up, you may want to consider some form of ECU tuning, Hondata has the new FlashPro about to ship (as of late June 09) and the Cobb AccessPort is already shipping. Both of these products promise the user some form of programming to complement commonly available modifications and the ability to do some custom tuning. More on this as feedback becomes available from more users of either system.

Now that you have stepped up your game in the power department, you better continue to improve the handling of your Civic Si with a strut/shock upgrade or make the move to "real" coilovers. Some type of improvement in suspension dampening with a level of adjustabiltiy would be nice. You usually get this with coilovers in addition to being able to adjust ride height and corner balance the weight of the car. Somewhere along the way, you should consider some form of camber adjustment to allow adjustments to improve handling and tire life...especially after lowering your Civic Si.

Still have some money left to spend on your Civic Si?

Superchargers from Comptech, Jackson Racing and soon Kraftwerks can put some boost into your K20Z3 and take it to the next level.

Turbos more your style? Seems like new turbo kits for this engine come available weekly.

At some point soon, you should consider a clutch upgrade that will be able to handle the power levels that these new mods will take you to. While you are doing the clutch upgrade, consider a lightweight flywheel for quicker revs.

Boost not for you? No problem! There are many parts now available to build an "all motor" K20Z3.

I hope you find this helpful and entertaining. I have only scratched the surface of the high performance aftermarket parts offerings for the FG/FA Civic Si. Now that this car has been in production for 4 model years, there are many fine, used examples out there waiting to be modified. Also, as more of these cars are built, more manufacturers of parts will consider offering parts for them.

Check out my website for more Civic Si performance parts and tuning information at http://www.newedgeperformance.com/index.asp?PageAction=VIEWCATS&Category=138

Tony D
New Edge Performance