How to Install Raceseng S1/S2 Pulley Kit on Subaru BRZ
Difficulty: Difficult
This write up will be a guide to the brave ones who decide they want to remove and install pulleys on their Subaru BRZ or Scion FR-S. The un-sprung difference in weight of the pulleys make a noticeable difference for the engine's responsiveness. It is definitely an affordable and fun mod.
Note: Since we are installing the S2 kit, we had to remove the two idlers. IF you are installing the S1 kit, you DO NOT need to remove the two idlers as they do not come in the kit.
Step 1
Place the transmission gear into the 6th gear position and apply the e-brake. If it's an automatic, please check the factory service manual for the proper locking procedures.
Refer to our BRZ Intake Removal Guide to remove the intake for an easier install.
Also, before taking any pulley's off, do not forget to take a picture or draw out the orientation of the belts, so they can be re installed properly.
Step 2
Use a 22mm socket and a 1/2 inch drive with a breaker bar to loosen the crankshaft bolt.
You may need to use 100 ft/lbs to get it loose. The engine will have a slight give, but just pull on it and it will eventually loosen.
Step 3
While the serpentine belt is still on the pulleys, use a 10mm socket with a ratchet to loosen the water pump pulley.
There are 3 bolts. Do not lose these bolts, as they are essential to the drive-ability of your vehicle.
Step 4
With a 10mm socket or wrench, remove the alternator cover before attempting to remove the alternator pulley bolt.
Once removed, use a 24mm socket and impact gun to now remove the loosen the alternator pulley bolt.
It is advised to use an Impact Gun for the alternator pulley removal because there is no other way to hold the pulley from spinning. The torque from the impact gun will remove the nut from the alternator without spinning it.
Step 5
With a 14mm socket and wrench, slowly turn the tension pulley clockwise until the belt is removable.
With the 14mm socket, loosen the bolts to both idler pulleys.
Step 6
Once the pulley's are loose, and all the bolts are loose, you can go ahead and slip the belt off of the pulleys.
Although the belt is loose, do not remove it, as you do not want to forget the orientation of the belts.
Step 7
With all the pulleys loose, now remove each one: the crank pulley, water pump pulley, alternator pulley and both idler pulleys.
Note: When removing the crank pulley, do not allow the crank pulley hub to back out of the timing cover. If this occurs, you will need to align the internal keyway with the crankshaft before assembly.
Step 8
Dont forget to keep all of the hardware together, as you DO NOT want to lose any of them.
These chubby pulleys are ready to be stored, and replaced with the lighter aftermarket ones.
Step 9
The removal of the stock idlers is not necessary for the S1 kit. Since we are installing the S2 kit, we have to remove the stock idler pulleys.
Carefully place everything in one place to keep the pulleys nice and neat. Depending on how you keep your hardware, its always good to organize them as well.
Disconnect the battery for your safety.
Step 10
Set the water pump pulley on the water pump and make sure the orientation is correct.
Use the blue thread locker on the threads of the bolt to keep it from coming loose.
With the water pump pulley on, thread in the bolts, but do not completely tighten them yet.
Step 11
Take the o-ring from the factory pulley and install it on to the crank pulley.
Then line up the crank pulley to the keyway and hand tighten the bolt with the thread locker on the threads into place.
Step 12
Now install the alternator pulley but do not thread the nut on yet.
Put blue thread locker on the threads of the alternator and thread on the nut for the pulley.
Step 13
If you ordered the S2 kit, you will now install the idler pulleys.
Put the blue thread locker on the bolt for the idler pulley
Then line up the holes and put the bolt through them. There are two idler pulleys that need to be installed, Repeat the process for the 2nd one.
Step 14
Install the belts in the order your removed them, making sure to leave the alternator belt last to slip over.
Step 15
Tighten and torque all the pulleys to the recommended specs.
Note: For the crank pulley, torque to 94 ft/lbs.
Place the vehicle in Neutral gear position and rotate the crank to make sure the belts are seated properly before turning on the vehicle.
Reconnect the battery and start the car with the E-brake on and in neutral.
Step 16
The difference in weight is 5.05 lbs. Imagine spinning something that is 7 lbs vs. 2 lbs. The difference is what the engine has been released of and can now spin a lot easier and quicker.
The car should be more responsive and perkier. A whole loads of Fun.
The installation of the light weight pulleys on the motor will definitely perk them up a bit. Just be sure that everything is torqued down, that way the engine runs smooth and well.