Street Friendly (And California Legal) GD Subaru STI Build! Part One

If you are a follower of MotoIQ, you are probably familiar with our way of building cars.  We tend to build innocuous-looking cars stuffed full of race car technology to build really hardcore sleepers.  There are a lot of inherent compromises in everyday practicality for attributes like ride comfort and general NVH when you build a car like this.  For this car, we are going to take a different approach,  We are going to build something more refined with very little impact on daily comfort, something like what the factory would do if they were to build a hotter model.  For our base, we are going to use a 2005 STI which is a fine, fun daily.  We are going to practically enhance it but not do anything that will have annoying attributes or affect its street legality, even in stricter than strict California.  In this first segment, we are going to go through the car’s brakes and shifting with some stuff from Hawk Performance, DBA, and Cobb Tuning.

First, it’s time to upgrade the brakes, here Jason removes the wheels to get going.

The STI comes with pretty decent brakes from the factory.  Big Brembos on all 4 corners, 4-piston calipers on the front, and two-piston rear calipers.  We are not going to go total ham with a big power increase and huge R Compound tires so a mild enhancement is good enough. The stock Brembos work well but the OEM pads are dusty and tend to wear the rotors quickly.  Big racing-inspired brakes would be an expensive overkill and tend to be noisy with more squeaks from less noise preventing hardware with rattle from floating rotors.

For rotors, we used DBA 4000 series slotted OEM replacement rotors.  The DBA rotors are made of XG150 iron alloy with good frictional pad compatibility, dimensional stability, and thermal properties.  The rotors use DBA’s unique kangaroo paw pillar vanes for good heat dissipation and have pre-applied stripes of thermal paint applied for judging your brake system operating temperature.  The DBA rotors have corrosion-resisting e-coating on non-braking surfaces.  We have had really good luck with DBA rotors for track day use on performance cars.  They are vastly better than no-name aftermarket replacement OES rotors available from undercar parts distributors.

For pads, we ran Hawk PC or performance ceramic.  Hawk PC pads are designed to have a consistent high coefficient of friction across a wide temperature range.  They are not a high temp race pad that doesn’t work at low temperatures!   They are a little better than stock performance brake pads but they make way less dust, are very quiet and have excellent rotor wear properties.   The pads are good enough for light track use but for serious track use with a street car, the HP Plus pad is a better choice.  For a daily driver pad, it’s hard to beat the PC compound.

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