Perrin Performance has introduced a lightweight accessory pulley kit for the Scion FR-S and Subaru BRZ engines. And it couldn’t have come sooner as we prep our own Project FR-S for the upcoming race season, click here to follow Project FR-S.
The precision balanced pulleys are CNC machined from 6061T6 billet aluminum and replace the stamped steel OEM alternator and water pump pulleys. The kits are available in anodized red or black.
With a combined .584 lbs mass reduction over the OEM pulleys, the Perrin kit equals a 30% reduction in rotating mass, which frees up horsepower. The precision balancing also minimizes unwanted engine vibration.
One of the most common questions we often field regarding underdrive pulleys is “Do Underdrive Pulleys Really Work?” And the answer is a resounding yes, by decreasing the amount of parasitic drag on your crankshaft pulley and engine you are freeing up horsepower and torque.
We’ve seen gains from 6 all the way up to 14 on our Dynojet 448X but your results may vary. However it’s not all roses and fun in the world of underdrive pulleys. Which brings us to the second most asked question when it comes to underdrive pulleys.
Q: What kind of problems can underdrive pulleys create?
This will really depend on your car and the situations regarding how you drive the car and where you live. If your car is equipped with aftermarket stereo systems and requires a large draw, you may experience problems with charging. Alternately, if your vehicle is older, equipped with a smaller battery or a weak charging system the underdrive pulleys may compound or increase your problems.
Raising your idle by way of your tuning computer, changing values in your ECU or just artificially raising the idle using a Idle screw can offset some of these charging problems.
Q: I installed aftermarket underdrive pulleys and now my car is overheating!
As with the situation regarding your vehicle’s charging system, a poorly designed cooling system or fan design may lead to your car overheating with aftermarket pulleys. If pulleys are the only thing you have changed on your vehicle, you may want to look into installing a lower thermostat to help with the cooling on your vehicle.
Coolant must also stay in the radiator long enough to lose heat before returning to the motor so you can actually move coolant too fast. Both these issues can be solved by using underdrive pulleys.
Perrin is stepping up to the plate to provide top notch components for your Scion FR-S or Subaru BRZ. Regardless of whether or not your FRS is forcefed, these Perrin components build on the name and excellence of Perrin products overall.
Part #: PSP-ENG-120BK (Black) MSRP: $177.00
Part #: PSP-ENG-120RD (Red) MSRP: $177.00
These pulleys can be paired with the Perrin lightweight crank pulleys (PSP-ENG-101BK [Black]/PSP-ENG-101RD [Red]) and can be installed in 30 minutes with basic hand tools. Some special tools are required such as an impact wrench to zip off the alternator pulley and a crankshaft dampener puller if your installation requires removal of the crank pulley / harmonic balancer.
Perrin Performance offers a 5 Year (60 month) warranty on the pulley kits, and we’ll be shipping these with the arrival of our first shipment on 6-7-2014!