We are extremely excited to present our 135i / 335i 3" Hi-Flow™ downpipes, now with Magnaflow race cats! The only TRUE 3" catted downpipes currently on the market! In addition to an intoxicating and exotic sound, these downpipes add significant power and virtually eliminate turbo lag, making the fabled N54 engine even more responsive!

Our Hi-Flo™ 3" Downpipes w/Race Cats Feature:

The only TRUE 3" catted downpipes currently on the market! 3" tubing until cat-back flange - all systems currently on the market reduce to 2.5" much closer to the turbocharger.

100% hand crafted in the USA from premium 304 Stainless Steel (cats are made from 409 Stainless) - flanges and O2 bungs included!

Water-jet cut 304 Stainless cat-back flanges, and CNC'd 304 Stainless V-Band flanges.

Magnaflow 3" metal substrate race cats

100% TIG welded, argon back-purged.

Set of our exclusive bomb-proof exhaust gaskets included.

Grade 10.9 Metric Hardware (145,000PSI tensile strength, C32-C39 Rockwell, Zinc Plated), and Nord-Lock positive locking re-usable washers included.

Factory location O2 bungs

Available with a 2000°F ceramic coating. Coatings come with a 3 year warranty against corrosion and rust to original owner.

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 1600°F. Such temperatures will  also rapidly deteriorate the polished finish.

NO CEL on pre 29.2 Progman cars - post 29.2/MSD81 testing is currently being completed, but due to the superior quality of the cats, we expect no issues.

More information on AR Design Ceramic Coatings

The coatings AR Design offers are capable of withstanding temperatures of 2000°F. In addition they offer excellent chemical and corrosion resistance and possesses 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, iconel 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°F coatings are available in the following colors:

Satin Grey Ice, Satin Titanium, Satin Blue, Satin Fresh Blast, Satin Grey, Satin Black.

Call for pricing on ceramic coating.