Seats

As important as your car's suspension and just as influential in its handling, your driving seat is of important to you being able to control your car and maneuvering it the way you want it to. Although some may argue there are better things to spend your money on first, the seat is definitely in the top 10 list of things you must replace if you are serious in being able to drive your car. A big reason for this would be because you won't be able to control your car properly because you keep slipping out of your factory seat while going around turns. The factory seat was designed for comfort and ease of entering/exiting the car, holding you in place while to fly around a turn at over 60kph.

There are two types of bucket seats available as upgrades to your car interior/handling.
-Full Bucket: Holds you firmly in place in the turns. Same style as seen in race cars.
-Reclining Bucket: Holding capability is a lot better than factory seats, but less than the Full Bucket. Much more comfortable and easier to live with than a full bucket. Capable of reclining.

There are a variety of companies specializing better holding sports seats available. In Japan, the two biggest brands are Bride and Recaro. Both brands make seats of the highest quality, and both have large and loyal user/customer bases supporting them.

Bride is most well known for their Zeta line of Full Buckets and the Brix Reclining Bucket. Recaro on the other hand, the SP-G Full Bucket and the SRIII Reclining Bucket.

Commonly heard opinions on the two competing brands is that the Recaro SP-G is more comfortable than the Bride Zeta, however the Bride has much better holding capability than the Recaro.

Being an owner of an older model Bride Zeta II, I like the looks of it and am satisfied by its comfort. I have been able to go on long 3 ~ 4hr drives without getting uncomfortable. I have never owned a Recaro before but have sat in one at the recent Tokyo Auto Salon, and I have to say, the few second sit-down in their newer model Full Bucket made me want to switch over.

Bride and Recaro are highly recommended and before making a purchase I highly suggest trying each out before making a decision.

Check out what we have to offer HERE

LSD Limited Slip Differential

The Limited Slip Differential (LSD) is the device that sends the power from the engine drivetrain to the wheels. Unlike the differentials coming from the factory, these differentials don't limit the amount of power transferred to one tire or the other. Instead, LSD's send power to both left and right side equally, resulting in a sportier ride, and faster acceleration.

In the Aftermarket tuning world, there are three types of LSD's:
1 Way
2 Way
1.5 Way

The 1 Way LSD is commonly recommended for drivers of competing in traditional racing. The LSD is engaged, sending power to both wheels during acceleration, however that power deliver stops when you let off of the gas.

The 2 Way LSD is engaged at all times regardless of whether or not the the throttle is on or off. The type of LSD is recommended for FR platforms and on the rear of 4WD platforms. The 2 Way is favored among drivers into Drifting and those who like to cruise up and down the mountainside with a tail happy car.

The 1.5 Way LSD is designed to have the best of both worlds. It is engaged during acceleration and is mildly engaged (not completely like the 2 Way) when the throttle is off.

Depending upon the type of things you do or wish to do with your car, you will need a specific LSD from the listed and explained types above. Great brands to get your LSD from include but aren't limited to: Kaaz, Cusco, ATS and others.

Check Out a few examples of Limited Slip Differentials HERE

Meters and Gauges

Making changes to your car is what tuning is all about. When switching out exhaust pieces for larger diameter replacements, or switching out injectors for better fuel delivery, you are changing the amount of power your car produces or amount of fuel it is able to drink. To help monitor the vitals of your engine, companies like HKS, Trust, Apex'i make meters/gauges to help you keep track of your temperature, pressure, and boost levels. The necessity and popularity of aftermarket meters/gauges are so high, there are companies that specialize in strictly making gauges. Some examples of these companies include Defi, Pivot, Stri, and others.

The following are the most common meter/gauge types available:
-Boost Pressure
-Oil Pressure
-Fuel Pressure
-Oil Temperature
-Water Temperature
-Exhaust Temperature
-Tachometer

Check out a few examples here: HERE

Tires

The four chunks of rubber keeping your car on the road and going where you want them to go...

Like everything else on the car that can be interchanged with good and even better parts, tires can be bought in various tread patterns, sizes, brands, and application types. For the performance enthusiast and serious circuit racers, there are the Sports and Racing tires, also commonly called Street Radials and S Tires.

Like Wheels tires also a coded jumble of numbers and letters to decipher to figure out what it is you are buying.
For example: 215/45ZR17 87W
215: The tread width of the tire
45: The height of the sidewall (side of the tire)
ZR: The construction quality of the tire. In this case, the tire is a Z-Rated Radial able to go to speeds beyond 240km/h without falling apart.
17: The size wheels the tire is compatible with.
87: The Load Index...
W: a repeat of the construction quality/speed durability.

If this description didn't really do it for you, go HERE for a better description + charts.

When looking around for sports tires in Japan, the well established brands are the first to come to mind first. Bridgestone/Potenza, Yokohama/Advan, Dulop/Direzza, Falken/Azenis, and Goodyear. However, with the high price for tires (Drifting especially), there is a growing market for cheaper alternatives from other parts of Asia. Federal, Nankang, Hankook, Achillies ATR, and others have been able to establish themselves as reliable brands, perhaps not quite being able to match the Japanese tire makers' quality, but are able to make up for that with pricing. Among Drag Racers, importing of American tires are common. Nitto, Hoosier, and Micky Thompson are common brand favorites among the list.

Depending on what you are using your car for, street/drag/drift/rally/circuit, there is a tire out there being made specifically to fit your needs.

Check out a couple examples HERE

Coilovers/Suspension

The legs of your car. The suspension is as important as the engine to making your car a great driving machine. It is what keeps your car on the road and assists your steering to controlling the car when flying around turns and on the straights.

A single coilover is composed of the following:
-Upper Mount: The plate which bolts onto the frame of the car. Also adjusts camber for Strut type suspension.
-Spring: Supports the weight of the car. Springs come in all sizes and Spring Rates (measure of how hard a spring is. Normally shown in kgf/mm measurements.)
-Lower Seat: Holds up the bottom of the Spring. Height adjustment is made with the raising and lowering of the Lower Seat in Coilover Suspension kits that are not Fully Adjustable.
-Bracket Lock Seat: Instead of raising/lowering the Lower Seat in your standard suspension to raise/lower the ride height of your car, the Bracket Lock Seat does the job without having to worry about messing with the spring in Fully Adjustable Suspension Kits.
-Damper: A case filled with oil and gas. A piston floating within the Damper is pushed down and rises up, resulting in "dampening."

There are many types of Coilover Suspension kits out there to choose from for any and every application. From the circuit only kit for the GT race machine to the family friendly van, there is something for everyone.

Check Out examples of Coilover Suspension Here

Wheels and Rims

"If a car was a woman, the wheels would be her tits." Anonymous

Every tuned car has to sit on a decent set of wheels/rims. Like every other aspect of car tuning, there are a wide selection of wheels available at your disposal. Lightweight, Forged, Cast, One Piece, Two Piece, Three Piece, Chrome, Bronze, etc. mix and match and you get endless possibilities. I haven't even started to mention offsets! With makers like Rays Engineering, SSR, Work, Watanabe, and others, you are bound to find something that both you'll like. When purchasing wheels, there are obvious things you need to know.

The Size. How big are the wheels you want to purchase?

The Width. Width is normally labeled as J or JJ. Wider the wheel, the bigger/wider the tire you'll need to wrap'em in, meaning more money. On the good side though, increased traction, stability, and better looks when coupled with streched tires (wrapping big wheels with small tires)

The Offset. How far the wheel face (the part with the design) is from the center of the wheel. The closer the wheel face is to the outside, the higher the positive offset and vice versa for negative offset.

The Bolt Pattern (commonly labeled as P.C.D. or Pitch Circle Diameter). This is the specifications of the part of the wheels that goes onto your car's wheel hub bolts. The number of hub bolts and space between them determines the P.C.D. you need for your car.

As an example, 17 x 7.5J 5 114.3 +48 means:
17in wheel
7.5J wheel width
5-Lug with a 114.3 bolt pattern
+48 offset

Know the specifications of your wheels and also how wide of a wheel/rim or low of an offset you can put underneath your fenders before buying wheels/rims. That way you will be more satisfied with your ride instead of having the headache of not being able to fit crazy sizes or being mad because you bought too conservative an offset, thereby killing the overall look of your car.

Check Out examples of Wheels and Rims Here

Exhaust

Like the Front Pipe and Outlet Pipe, replacing your car's Stock OEM Exhaust or Muffler is a great basic upgrade to freeing up horsepower and getting a better sound out of your car.

Another great thing about the exhaust is that it counts as both a power upgrade and an exterior modification. The rear of your car will look more aggressive with the addition of the exhaust sticking out from underneath your rear bumper.

And now for the sound. The way your car will sound and feel will depend on which you choose out of the abundant exhaust out there. Exhaust pieces come in a wide variety of shapes and materials. The exhaust tip shape can come in the popular Canister-style, the quieter, uglier Oval-type, and the simple looking Straight-type. Then you have the Main Pipe which is connected to the catalyzer and runs towards the exhaust tip. Piping diameter will be larger than Stock to add power to the car while resonators aka pre-mufflers will also be welded in to reduce the overall sound coming from the exhaust...or not. Composition material commonly is Steel, Stainless Steel, Titanium, and if going custom, even Aluminum!

Those who want ear splitting sound, Full Straight Exhaust. For those who want a little bit of oomph in their ride minus the sound, there are exhausts packed with glass fiber wool and resonators to keep sound to a minimum.

Because I love my car's exhaust note, a full straight exhaust is for me. No muffler, no resonator. The uninterrupted, raw sound of an car is amazing to hear and reminds me every-time why I love cars.

Check Out examples of the Exhaust/Mufflers Here

Intercooler and Intercooler Kits

The intercooler is an integral piece of equipment within the turbo charger system. It acts as a heat exchange for the compressed air that is forced through the raging hot turbine. Most all intercoolers in Japan use air as the agent for cooling however there are some that use water to transfer the heat from the intercooler core.

There are three types of Intercooler kits that are made here. They are denoted by the mounting location. FMIC which means Front Mount Intercooler Kit and has the intercooler mounted in the front of the car behind the bumper. TMIC which is Top Mount Intercooler Kit and finally SMIC, or Stock Mount Intercooler Kit. The difference is that some SMIC intercooler kits are not top mount.

The compressed air flowing through a tuned turbo system to your intake can reach over temperatures of 100 C. The thing that makes this a bad situation is that warm air is more prone to detonation, knock or pre-ignition. So the warm air is less dense and not good for performance and the large turbine you run the hotter your intake air is going to get.

Things to consider when selecting an intercooler are; not all intercoolers are created equally and bigger is not always better. Intercoolers come in many different styles and there is a fine technology behind a core and its cooling capability. It is possible for you to buy a cheap intercooler kit that has a larger core and have it be less effective than a good Japanese intercooler of lesser size. Some factors to consider is internal passage size, internal passage design, weight and core size. The Trust Greddy Spec R intercoolers are our most popular intercooler kit.

Intercooler Kits can be found here.

Turbo Down Pipe Front Pipe and Outlet Pipe

A Turbo Down Pipe (known as a Front Pipe here in Japan) with an outlet pipe is a great way to start tuning your turbo equipped car. As the same with the intake you want to remove restrictions to the exhaust gasses running out of the turbo so that the turbo can spool up faster and more freely.

The outlet pipe is the elbow pipe that directly connects to the turbo and vents down. This pipe is a short pipe and will often have an O2 mounting hole in it. There are two types of front pipes. The first front pipe style is a pipe that connects to the outlet pipe and goes to the catalytic. There is another front pipe and this is the type that includes the outlet pipe in it so it looks like the two of the above pipes connected as a full unit with no bolts and flanges connecting them. This style is the style that you get when you order big turbine kits but lately this style has been made available for stock turbines as well.

The OEM setup is constrictive and will not allow your turbo to flow to its full potential. It is an easy swap, relatively cheap and there are many that can be used with your stock turbo. A very popular set up for the beginner tuner is to go with a down pipe and outlet pipe, exhaust, suction intake kit, boost controller, and AFC.

Turbo Down Pipes come in steel, stainless steel, and titanium. Although we like titanium if you are drifting or road racing they are fragile and you will most likely damage it if your car is lowered. We recommend stainless steel units from Trust. Tomei outlet pipes are very nice as well.

These Turbo Down Pipes, Front Pipes, Outlet Pipes can be found here

Turbo Charger and Turbo Kits

A non turbo engine is inefficient as it looses a large about of the energy produced through heat and exhaust. A turbo can be used to harness that energy and recycle it back to the engine. This was a great discovery for the racing and performance enthusiasts world.

With that in mind the turbo has some basic components and is a very simple mechanism on its basic workings. A turbo charger has a compressor side (cool intake side) and a turbine housing side (hot exhaust side). The turbo charger simply compresses the intake air and forces it in to the engine by use of the exhaust gas being forced out of the engine. A turbo charger is composed of two fans attached to the same rod essentially. One fan is in the exhaust housing and it spins as the exhaust gasses pass past the blades. The impeller (fan) in the exhaust housing is connected to a shaft that runs thorough the center cartridge of the turbo and in to the compressor housing side. The shaft rotates at speeds in excess of 100,000 rotations per minute (RPM) and is cooled by oil. The compressor housing houses another fan called the compressor wheel. This wheel forces air in to the intake piping and thus the intake is pressurized. This pressure is referred to as boost. The more exhaust gas is forced out of the engine the more boost the turbine will produce. The amount of pressure (read here engine RPM) it takes to make boost is considered turbo lag.

There are determining factors to max boost and turbo lag such as housing sizes, impeller and compressor wheel sizes and housing design to name a few. A turbo charger is a very integral part to high horsepower tuning because it harnesses lost energy from the engine exhaust and in a way recycles it to the intake system. Turbos vary in sizes and design and there are many makers around the world. Japanese turbos and turbo design tend to be some of the best in the world.

To view JDM Turbos and Turbine Kits click Turbo Charger

Suction Intake Kit

The intake system of your car while effective as a stock system it is hardly up to the task of supporting higher horsepower and performance upgrades. It is important when tuning this system of the car to remove as much resistance while maintaining the integrity of your filtration system and allowing for smooth air flow.

There are a variety of kits available ranging from ones that just swap the stock filter with a more performance based and higher flowing one to those that replace all the stock intake piping and air box. The piping is most often aluminum and the boxes are as well. There are sometimes variations in the high end boxes in which they incorporate carbon fiber. No matter what they are made of they all allow for more air to be fed to the engine with less resistance and with them installed your engine will feel more responsive when you suddenly hit the gas.

It is important to remember that more air in the intake will only increase performance to a point. It will also lean your Air Fuel mixture out. Therefore it is good to accompany an intake kit with an AFC or other engine management that will allow for setting the mixture of you car to match the increased air intake. RHDJapan recommends Trust Greddy Airinx and HKS Super Reloaded suction kits.

You can check these JDM products here Intake Kit

Spark Plugs

Spark Plugs are a very important part to tuning your engine. Many tuners here in Japan say that in countries where gas quality is less than here in Japan, ignition and spark plugs have even more importance in tuning. The key factors to high horsepower is good quality gas, good ignition, and ignition timing and because good gas is not always accessible you will definitely need good spark plugs.

The Spark Plug has a two major requirements, one is to provide a good spark and the other is to keep cool. If a spark plug becomes too hot due to high boost or high compression it may cause detonation or knock. Detonation, knock, or also called pre-ignition will destroy your engine and should be avoided like the plague.

Spark plugs are rated with a heat range from 6 to 10. This is not the case with the Wankle engine as rotary engines are rated at 9 to 11. A heat rating of 6 is for stock piston engined cars and 10 is for highly modified cars. While there is no specific formula we can offer in determining what plug heat range you need most mildly tuned piston engines use one heat range higher than the stock 6. The most popular and widely used plugs here in Japan are the HKS M Series plugs. There are many other types of spark plugs out there and many different types of engine tunes so it sort of comes down to personal choice for many. We always recommend HKS M Series over all others.

You can view these JDM parts Spark Plugs

Plate Clutch Kits

The clutch system is a very important part to your drive train technology as it acts as the first transfer point for engine power on its way to be converted to rear wheel power.

There are two rotating parts to a clutch; the clutch plate assembly, and the flywheel pressure plate assembly. The flywheel pressure plate assembly is attached to the crank and spins regardless of whether the clutch pedal is in or out. The clutch plate assembly is connected to the spline gear that has the tip poking out of the transmission bell housing side. This part when the clutch pedal is depressed does not spin with the flywheel assembly.

What should you consider when you are purchasing a clutch for your car? There are many factors when considering a clutch kit for your vehicle. Flywheel weight, pressure plate clamping force, clutch disc material, clutch disc springs, clutch surface area are all important. Flywheel weight will determine how fast your engine revs go up and how much torque can be transferred to the transmission. Pressure plate clamping force is a determining factor in how much power the clutch can handle before slipping. Clutch disc material will determine how responsive and sticky your clutch engagement feels. Clutch springs in the plate help to dampen the initial shock of the clutch disengagement which will dampen the initial force on the transmission (springs help your transmission live longer). Clutch surface area determines the gripping area of the clutch disc which relates to how much power a clutch can hold as well as how abruptly it disengages. More clutch surface area can be achieved by using a bigger clutch such as the OS Giken C series clutches. Another way is by adding more plates to the clutch assembly. We recommend OS Giken clutches as they are the absolute best quality out there.

These JDM parts can be found here Plate Clutch Kits