Audi A3: Begining Performance Mods for S3

This article applies to the Audi S3 8V (2013-Present).

Your Audi S3 is a superior sport sedan designed for the enthusiast driver, but there are still basic mods to improve torque and horsepower, as well as reduce unsprung weight, to enhance the competitive performance of this capable platform. For a better appreciation of performance modifications, we will be discussing the following terms:

• Sprung Weight: The frame and body of the S3, and everything in it, that is riding on the suspension springs.
• Unsprung Weight: The parts of the S3 suspension that are not supported by the springs. This includes the drive axles, brakes, wheels and tires. Unsprung weight has inertia that resists changing direction; such as suspension motions and quick steering transitions. The brake rotors, wheels and tires are rotating unsprung weight, that sap engine and brake performance in the effort to spin them faster and slower. As a general rule, adding one lb of unsprung weight has the performance effect of adding seven lbs of load, with rotating unsprung weight being the most detrimental.

Beginning Performance Mods Components Breakdown

APR Carbon Fiber Engine Intake

DIY Cost – $510

Professional Cost – $750

Skill Level – Easy; requires basic tools, with good access under the hood and no jacking is needed.

With a high flow, reusable filter and tuned airflow, the APR Carbon Fiber Intake System boosts your S3's horsepower and torque, and announces your arrival with an aggressive intake snarl. The APR system's cold air, ram inlet mates up to your stock grill and the volute chamber distributes ram air pressure evenly around the filter for maximum airflow and filter service life. The glossy 2 x 2 carbon fiber weave adds engine-bay class that will make you want to lift the hood, whenever your S3 draws spectators.

Some versions of the EA888 engine have secondary air injection, which operates on certain cold starts. When activated by the computer, the SAI pump draws filtered air from the airbox and pumps it into the exhaust manifold, where the additional oxygen burns and lights off the catalytic converter more quickly. If so equipped, some S3s may have an SAI inlet hose attached to the side of the stock airbox. The APR carbon fiber airbox does not have a fitting for the SAI hose, so APR provides a small filter which is attached to the SAI hose and the hose is then secured with zip-ties, as shown in Figure 2.

For drivers who enjoy additional power and aggressive sound from their turbo-charged intake system.

AWE Tuning SwitchPath Cat-Back Exhaust

DIY Cost – $1,850

Professional Cost – $2,200

Skill Level – Moderate to Difficult; involves jacking the S3 onto jack stands and exhaust system disassembly. An assistant may be helpful.

When you have to drive your boss across town to see clients, the AWE Tuning SwitchPath exhaust purrs quietly. But alone on the back roads, put your foot down and unleash your S3's free-breathing, vigorous howl. The SwitchPath is dyno-tested to free up as much as 17 horsepower and 23 ft-lbs of torque, as measured at the crank shaft. The T304 stainless steel pipes are 3" in diameter and mandrel bent for uninterrupted flow. The AWE system will reuse your Audi exhaust valve actuator motors, which will be swapped over during installation. As an added benefit, you can finish your S3's appearance with quad exhaust tips in Chrome Silver or Diamond Black, for slower drivers to admire briefly as you pull away.

For drivers seeking more acceleration and throaty sound under open throttle.

ECS Tuning Four-Wheel Brake Upgrade

DIY Cost – $1,475

Professional Cost – $,1900

Skill Level – Moderate; requires jacking the S3 and knowledge of brake system assembly.

Your S3 is equipped with 13.4" vented front rotors and 12.2" vented rear rotors. Single-piston calipers provide clamping force at all four wheels. Total unsprung weight of the upgradable brake parts is 42.1 lbs at each front wheel and 24.6 lbs at each rear wheel. Basic upgrading of the rear brakes is limited to using high performance rotors and pads, by the integral electromechanical parking brakes mounted on both rear calipers.

However, big brake kits often use larger, heavier components, which can dramatically increase rotational unsprung weight and sap the extra power you just made with the APR intake and AWE exhaust. Conversely, the best way to improve your S3's performance is to reduce unsprung weight with lighter rotors, improve friction with high performance pads and reduce fade with high temperature brake fluid.

• The ECS Tuning 2-piece floating rotor with aluminum hat, bolts directly on. Its aluminum hat reduces unsprung weight and its curved, directional vanes improve cooling performance over OEM.
• EBC RedStuff Kevlar brake pads improve both hot and cold friction, for lively street performance and their low dust formula greatly reduces the well-known OEM brake dust problem.
• Because stainless steel brake lines do not flex and expand under pressure, they provide a firmer and more responsive brake pedal.
• Brake fluid is designed to absorb moisture. When subjected to extreme temperature in the calipers, that moisture boils, creating compressible vapor and causing dangerous brake fade. The dry boiling point is measured with new fluid, and the wet boiling point is measured after the fluid has absorbed 3.7% moisture, which typically takes two years. Motul RBF 660 brake fluid has a dry boiling point of 617°F and wet boiling point of 401°F, providing greater protection from overheat fade than the Audi B000-750-M3 fluid, which boils dry at 509°F and wet at 338°F.

For drivers who appreciate outstanding stopping power and a very responsive brake pedal.

Scheduled Maintenance

If you Autocross your S3, the maintenance schedule should include brake caliper bleeding before every race, and brake inspection after every race.

Common Questions

Are EBC RedStuff pads suitable for racing?

RedStuff Kevlar enhanced pads are designed for spirited street use and occasional Autocrossing. For extensive track driving, racing pads should be used.

What do the S3's stock brake components weigh and what are the Audi part numbers?

• Front caliper: 10.5 lbs. (Left 8V0-615-123B, Right 8V0-615-124B. Painted black, single piston with S3 emblem)
• Front bracket: 5 lbs. (Left 8V0-615-125B, Right 8V0-615-126B. Painted black)
• Front rotor: 23.6 lbs. (1K0-615-301AD, 340x30mm. Minimum thickness 27mm)
• Front pads: 5 lbs per wheel. (8V0-698-151C)
• Rear caliper: 5.9 lbs. (Left 8V0-615-423E, Right 8V0-615-424E)
• Rear bracket: 2.4 lbs. (Left and Right 8V0-615-425B)
• Rear rotor: 15 lbs. (1K0-615-601N, 310x22mm. Minimum Thickness 20mm)
• Rear pads: 1.25 lbs per wheel. (3Q0-698-451)

Common Issue

Brake Pads and Dust

The OEM brake pads are well known to generate lots of dust. Additionally, for autocross racing, dedicated racing brake pads are designed to be most efficient when hot and they will make a lot of dust. Mitigate the corrosive effects of brake dust by protecting your wheels with ArmorAll Wheel Protect or Opticoat Pro. Otherwise, switch to dual-use pads such as RedStuff, which are designed for both cold and hot friction and low dust in daily use.

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