UPgrading to the AP Racing Endurance 325mm kit from Essex Motorsports

Flatirons Tuning Tech Tip - Upgrading to the AP Racing Endurance 325mm kit from Essex Motorsports

After many years of reliable service, the time has come to upgrade the brakes on the 2003 WRX Project car. The brake kit we chose is the 325mm AP Racing Endurance brake kit put together by Essex Motorsports, and in this video we will go into all the details about this kit that helped is make our decision.

Remember, you can't go fast around the track unless you can stop fast too!

Thanks for watching!

If you would like more information, here is a link to this kit on our web-site:

Here is a summary of the key points discussed in the video:

The Relationship Between Tires and Brakes [00:06]
Tire Traction is the Limit: A brake system's effectiveness is entirely limited by the traction of your tires.

Skinny/All-Season Tires: If you install a massive big brake kit but run skinny or high-treadwear (e.g., 600 treadwear) all-season tires, the brakes will simply engage the ABS very quickly without actually stopping the car much faster.

Sticky/R-Compound Tires: Conversely, running very aggressive summer tires or R-compound slicks provides so much grip that stock brakes might struggle to even engage ABS. In this scenario, you need a brake upgrade just to take full advantage of the grip your tires provide.

The Problem with the Previous Setup - Subaru 4-Pot calipers[01:27]
The Old Setup: The 2003 WRX project car was previously running a 2.0L engine (~240-250 whp) with Subaru 4-pot front calipers (Hawk DTC-30 pads) and an H6 rear rotor upgrade (Hawk HT-10 pads). This setup was perfectly balanced for the power level and the 225-width R-compound tires.

The Issue: After upgrading to a 2.5L engine, the car carried significantly more speed. Despite adding brake cooling ducts, the extra heat generated by slowing down from higher speeds proved to be too much for the old setup.

The Damage: After a track day, the front brakes were making a horrendous noise and required excessive pedal pressure just to stop at a normal traffic light. Upon inspection, the rotors were warped, the external dust boots on the 4-pots were completely burned away, the paint had burned off the pads, and the pad material was completely glazed.

Why I Upgraded to the AP Racing Endurance Kit [03:31]
To prevent overheating issues from happening again, the host upgraded to the Essex Motorsports AP Racing Endurance Kit. This kit was chosen for several distinct motorsport-focused advantages:

Superior Rotors: The kit utilizes a 32mm thick, 72-vane AP Racing J-hook endurance rotor. This adds significantly more thermal mass and cooling capacity compared to the standard WRX rotors.

Weight Distribution: Even though the brake rotor is 1-inch larger in diameter, the total weight of the braking system did not increase compared to the old 4-pot setup. The mass was simply moved out of the heavy cast caliper and into the rotor where it is needed for heat capacity. It is also significantly lighter than a standard Brembo setup.

Motorsport Calipers: True motorsport calipers do not have external rubber dust seals, which eliminates the risk of them burning up under high track temperatures (as happened to the 4-pots). Additionally, Essex Motorsports can fully service and rebuild these calipers domestically in the US.

Thick, Cost-Effective Pads: The pads for this endurance caliper are significantly thicker than standard Brembo or StopTech pads. Because they are a standard racing shape, they are actually less expensive than comparable pads for OEM calipers.

Long-Term Value: The initial higher cost of the AP Racing kit is easily offset over time. Because the pads are cheaper, twice as thick, and run cooler, you will save a substantial amount of money on consumables after burning through 4 or 5 sets of track pads.