Add drive train rigidity and precision to throttle input to your Subaru with the PERRIN Performance Diff Lock Down System. This kit consists of two kits in one, the DLS and SLS. The DLS (differential lock down system) consists of 6 urethane bushings to lock down the rear differential support beams. This helps remove movement from the rear differential under extreme conditions such as drag racing and road racing. Under these conditions the drive train (diff included) will twist and move around before it starts to turn the wheels causing a squishy or spongy feel at the point of initial acceleration. The PERRIN rear diff lock down (DLS) locks the differential by stiffening up the front and rear mounts for zero movement so when you push on the gas, the car goes with no delay.
Also included in the kit is the PERRIN (SLS) Subrame lockdown kit. The rear subframe on the 02-07 WRX and STI is mounted to the chassis with rubber bushings. Under extreme conditions like road racing where high cornering forces are seen, the subframe moves around causing a loose feeling in the car. This also can cause the alignment of the wheels to change, also causing a feeling of looseness.
As you can see both the SLS and DLS goes hand and hand and can make a noticeable difference on your 04-07 STI. Fitment:
The ALTA Performance Group™ has been a pioneer and market leader in the performance aftermarket since our inception more than 10 years ago. Using the finest materials and labor, found here in the United States, you are assured that PERRIN™ stands for quality and value. Our customer service, sales and technical staff is always available to help you with questions or concerns. From live instant chat messaging on the website, to e-mail or phone, we pride ourselves on the unique levels of customer service we provide that are simply not found elsewhere in the aftermarket today.