Swaybar Rear 22mm
PSP-SUS-232
Prevent plow and improve handling with a PERRIN rear swaybar for 08 and newer WRX/STi
Install Difficulty Rating
Keep that Subaru Flat in the Turns!!
The only way to make your car turn, stop or go is if the entire available tire patch is hitting the surface at hand. The factory included what many regard to be a whimsical attempt to increase cornering with puny sway bars on the front and rear. PERRIN™ sees the need for far larger and stronger sway bars and now offers two choices for both ends of your car.
For street enthusiasts that simply want to attack the drive to work with more gusto, the 19mm upgrade is the ideal choice. While dedicated track hounds will delight in the increased snap now available from our 22mm offering. Each size and each end also incorporates 3adjustment holes to help you custom tailor your suspension to your specific needs and driving habits. Made from solid steel and heavily powder coated to prevent the rigors of salty roads that wreck havoc with less worthy products. All kits include polyurethane pocketed bushings to prevent tedious re-greasing and all necessary hardware fora clean, and painless installation.
Percentage Increase in stiffness over OEM WRX Rear 15mm Sway bar
Setting #1 Setting #2 Setting #3
PERRIN 19mm 205% 260% 340%
PERRIN 22mm 380% 480% 490%
Percentage Increase in stiffness over OEM 2009 WRX Rear 16mm Sway bar
Setting #1 Setting #2 Setting #3
PERRIN 19mm 158% 200% 260%
PERRIN 22mm 293% 372% 482%
Percentage Increase in stiffness over OEM STI Rear 18mm Sway bar
Setting #1 Setting #2 Setting #3
PERRIN 19mm 99% 125% 160%
PERRIN 22mm 185% 230% 305%
Look under your WRX. Go ahead, we’ll wait…. See that little sway bardown there? Replace it with a PERRIN Performance sway bar and wepromise better cornering, reduced body role and greater control overyour suspension. PERRIN Performance™ Sway Bars are bigger in diameterand come with multiple end-link attachments, giving you 5 possibleconfigurations.
How does a sway bar work?
First understand that a tire has flat contact patch. If the contactpatch is not parallel to the ground, the contact patch gets smaller. Inturn traction is lost. As the car makes its way through a turn, theweight of the car, causes the car to lean. As the car leans, the designof the suspension geometry makes the tires contact patch becomeunparallel to the ground. In turn loosing traction.
Suspension designers used camber to help counteract this, along withunequal control arms. But a large part of keeping the tire parallel tothe ground during cornering is controlling how much the car leans. This is where sway bars come into play. During cornering the sway baracts to keep the chassis from leaning. In turn this helps keep thetires parallel to the ground. Stiffening up the springs on the cardoes the same thing, but in turn makes the ride much harsher. Swaybars are like stiff springs but only become effective while cornering.
Swaybars connect both left and right control arms with a torsion bar.As the control arms move up and down together, the bar moves withthem. During this state the sway bar has no effect. Only when thecontrol arms move in opposite directions does the sway bar come intoplay. During a corner, the outside arm moves up and the inside armmoves down, in turn causing the sway bar to twist. The opposingdirections of the arms are counteracted by the sway bar and the swaybar tries to keep the arms from moving in opposite directions. In turnkeeps the car from leaning less, and give you more traction!
Why do I want this?
That is easy to keep the contact patch as flat to the ground aspossible! Both front and rear sway bars do different things to cars. Both front and rear sway bars increase traction to the outside tire(the one with the most load), but a balance of front to rear can changehow the car handles.
All cars are designed to have a slight amount of understeer. This isdone for safety reasons. Understeer is the effect when you go into acorner, and your turn the wheel, but the car goes straight. This isalso known as pushing or plowing. In contrast Oversteer is when you gointo a corner, and the car turns more than you steer. This is alsodescribed as the rear end feeling like it is sliding out slightly. Toomuch oversteer and you will spin out in a corner. Too much understeerand the car will not turn through the corner, and go straight off theroad.
Generally people prefer neutral handling or a slight amount ofoversteer. With the choices in bar sizes and endlink settings, anyonecan find the perfect match to their driving style.
Hollow vs. Solid
Given both are designed to produce the same rate or stiffness, theyboth do the same job. But in order to get a hollow bar to produce thesame rate, a very large diameter is needed. And for those wantingsomething with a high rate or stiffness, you won’t be able to find thisin a hollow bar. Another benefit hollow bar makers try to sell is theweight. The difference in weight is very very small. To give anexample, a rear WRX PERRIN sway bar weighs 10.8lbs. Even if you removethe entire bar, the savings isn’t much. If weight is that critical,you can always remove your spare and save more weight. All PERRIN swaybars are made with solid 4140 Steel bar. This provides the best in bothstiffness and durability, and creates a bar that will last forever.
Sway bar Settings
All PERRIN swaybars comes with multiple endlink connections. Thisallows the end user to customize the stiffness of the bar. All PERRINswaybars come with at minimum 2 settings. These 2 settings can provide3 actual different setting with crossing the endlink connections. Our3 setting swaybars can provide 5 different setting by doing the samething. Below are some basic calculations of % change from OEM toPERRIN 19mm and 22mm bars. The crossed endlink calculations are notmentioned below, but can be figured as they will fall in between therates mentioned. The sway bar settings can allow for significantchanges in sway bar functionality, with out having to go buy anothersize bar.
Fits ALL WRX and STi 2008 and newer Sedan and H/B
Download Instructions:
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