Finally a proven, high-flow downpipe solution for your C5 A6 2.7T. The ar design 3" downpipes increase the diameter of the piping almost 1 full inch over stock downpipes, making them the largest tubes that will fit on the S4. Not only does the increased 3” diameter minimize backpressure to allow for quicker turbocharger spoolup, and free up horsepower (over 30awhp gains on a PJK04 S4 from “piggie” pipes), they also add an intoxicating, aggressive sound. The optional race cats further reduce the flow restriction caused by the stock catalysts.

You can opt for either high flow race cats (emissions friendly in most states) or test pipes (no cats) for off-road and track use. We also offer a V-Band setup that allows you to swap between test pipes and high flow race cats in just minutes.

Features:

• 100% Hand Crafted in the USA from premium 304 stainless steel - flanges and O2 bungs included!
• 3” Mandrel bends
  
• ½” thick 304 Stainless, and CNC'd 304 Stainless V-Band flanges.
  
• 100% professionally TIG welded, and argon back-purged.
  
• Available with a 2000°F ceramic coating. Coatings come with a 3 year warranty against corrosion and rust to original owner.
• ar design backs our downpipes with a lifetime warranty against any manufacturing defects given to original owner.
• We do NOT grind/polish our welds as some other manufacturers do. Grinding welds compromises the strength of the weld, and can lead to weld failure! Especially critical in applications exposed to temperatures in excess of 1200°F. Such temperatures will also rapidly deteriorate the polished finish.
• Available for MANUAL transmission vehicles only
  
• Will bolt up to most aftermarket cat-back systems
  
• Option for high flow race catalysts, test pipes or both

More information on our Ceramic Coatings

The coatings we offer are capable of withstanding temperatures of 2000°F. In addition they offer excellent chemical and corrosion resistance and possess excellent thermal barrier characteristics, providing a dramatic reduction in radiated heat. This means reduced under-hood temperatures, accelerated exhaust gas velocity and a longer life expectancy for the downpipes.

Ceramics stand above all other thermal barrier coatings currently being used in combustion chambers. Ceramics have characteristics shared by no other product, providing an unrivaled layer of thermal protection to piston tops, aluminum heads, stainless, inconel and titanium valves. Ceramics "move" heat, reducing detonation and increasing the effective oxidation of fuel. When polished, it provides a highly reflective surface that further aids in improved flame travel. Unlike previous ceramic coatings, ours is not subject to cracking and flaking, which can lead to extensive engine damage. In fact, Ceramic coatings actually strengthen the coated part. The cured "Cermet" provides a cap of material that can withstand far more heat. During testing when sufficient heat was applied to a piston to melt the aluminum, the Ceramic did not melt, rather it held the softer aluminum together.

The Satin Ceramic Exhaust Coatings we offer are the most advanced exhaust system coatings available. They are a very durable ceramic-reinforced coating available in various shades. When properly applied, it becomes the most effective thermal barrier coating available, increasing performance while extending component life, and has been tested to over 2000°F without lifting, cracking or flaking

2000° coatings are available in the following colors:

Please add 2-3 weeks to delivery time for coated downpipes, or call to see if we have your choice of color available in stock.