Restrictions in the exhaust system robs horsepower and torque especially on turbocharged cars. Thus, removing as much exhaust flow restrictions will increase horsepower and torque significantly. The factory catalytic converter found in the factory downpipe is a big culprit of this and is a major exhaust flow restriction. The factory catalytic converter is made up of catalyst material formed into "honeycomb" weaves. Exhaust gas must pass through these tiny "honeycomb" weaves on their way to the exhaust system thus causing a major exhaust flow restriction. It also causes turbulence after the catalytic converter which causes the exhaust flow to slow down (which increases restriction). By replacing the factory downpipe/catalytic converter with our Competition Series 4" Catless Downpipe, more power is unleashed! Our dyno testing has shown around 14-16whp average peak gains and upwards of 24wtq peak gains! While peak horsepower is nice to look at on dyno charts, what's more important is the power curve. If you look at the dyno charts, torque hits MUCH earlier and harder. The torque curve is BROADER throughout the RPM band. More usable power. You have more time spent in the RPM band with higher horsepower and torque. This equates to faster turbo spool up (less turbocharger lag) and better throttle response. Bottom line, faster. You will feel the difference instantly.
Our Competition Series Catless Downpipe is constructed out of 100% 304 grade stainless steel and utilize mandrel bent piping. They are 100% TIG welded by our in house fabricators and built in the USA. The factory turbocharger turbine housing utilizes a 4" V-Band flange which we have duplicated and CNC machined cut out of billet 304 stainless steel. Stainless Steel CNC machined O2 sensor and laser cut brackets are TIG welded using stainless steel rods. The O2 sensor is positioned at the factory location. Since the outlet of the turbocharger is 4" and the factory exhaust system is 2.5", the factory downpipes reduces size using short transitions from 4" before the catalytic convert and 2.5" afterwards. Due to space needed for the cataylic converter, the factory downpipes reduce in size using very short transitions. Since our catless downpipes delete the cataylic converter, we have more space. Thus, we use very long transitions. These longer transitions allow the exhaust gas time to smoothly transition from the larger piping to the smaller. This results in less exhaust turbulence and backpressure which again improves throttle response and increase turbocharger spool times (less turbocharger lag).
The factory downpipe utilizes a flex bellow section that allows the exhaust system to move. This eliminates undue stress on the exhaust components like the exhaust system, downpipe, turbocharger and exhaust manifold. Many of our competitors do not feel it is important to keep this. While you do not see any adverse affects right away, over time, the stresses caused by not having a flex section and having a rigid exhaust system will cause premature wear and tear. Any stress failures like cracks will form quicker than usual on exhaust manifolds and exhaust components. Also, without a flex section, the exhaust system cannot properly deflect impact. Especially on lowered cars, whenever the exhaust system contacts the ground, the entire system gets pushed up. Without a flex, you can imagine how much stress is put into exhaust components like the exhaust manifold when the exhaust is pushed upwards. We fully understand that durability of our products is important. Thus, like BMW, we incorporate a flex section into our downpipe. Our flex sections are 100% stainless steel (cheap flex sections only have stainless steel center braids and steel caps) to ensure corrosion resistance.
Our downpipes are designed to fit perfectly with either the factory exhaust system or your aftermarket exhaust system. There are no compatibility issues whatsover. The downpipes will come by default with either brushed or polished finish.
Optional Ceramic Thermal Coating
The purpose of ceramic coating downpipes is to keep heat from the exhaust gases inside the downpipe from radiating out. This keeps underhood temperatures lower and less heat absortion by nearby parts/surfaces. Another added benefit is that by keeping in heat (energy) in the exhaust gases inside the downpipe, exhaust flow velocities stay up, resulting in lower backpressure. The ceramic coating also adds additonal corrosion resistance. We utilize the best ceramic coating possible. Our thermal coating can resist up to 2000F of heat.
Optional Additional O2 Sensor Bung
An additional O2 sensor bung can be added so that you can easily add a wideband o2 sensor and gauges so that you can monitor air/fuel ratios. The additional O2 sensor bung will come pre-installed with a plug so that you do not need to run the o2 sensor right away.
Optional EGT (Exhaust Gas Temperature) Bung
An additional 1/8" NPT bung can be added so that you can easily add a EGT sensor and gauge. The optional EGT sensor bung will come pre-installed with a plug so that you do not need to run the EGT sensor right away.
- Horsepower gains of 14 to 16whp average (gains will vary based on modifications of your vehicle).
- Higher Max Horsepower Curve.
- Torque gains of 16wtq average (stock boost) up to over 24 wtq (Software upgrade) (gains will vary based on modifications of your vehicle).
- Higher Intial Torque Curve. Torque curve hits faster and higher and longer.
- Better throttle response and faster turbo spool up times.
- Mandrel Bent 4" piping. Smooth transition to the exhaust system.
- 100% Stainless Steel Construction
- 100% TIG welded for better quality welds
- Precision CNC machined turbocharger V-Band flange.
- Stainless steel flex section like factory that allows proper exhaust movement and flexibility.
- Mirror polish or brush finish
- Available with high temperature black thermal coating to reduce underhood temperatures.
- Optional - Additional O2 sensor bung for wideband O2 sensors (comes with pre-installed plug)
- Optional EGT sensor bung for EGT gauges (comes with pre-installed plug)
- Compatible with the factory or aftermarket exhaust systems.
- Track tested durability.
- Includes all hardware for complete installation.
- Limited Lifetime Warranty.
BMW F22 228i
BMW F30/F31 328i
BMW F32/F33 428i
WARNING: Please note that certain aftermarket exhaust systems may not comply with applicable US (including California) laws and regulations, and may therefore be prohibited for use on highways or roads, or on roads or vehicles otherwise subject to emissions control requirements. California prohibits the use of any aftermarket exhaust system that modifies, removes or replaces original equipment catalysts, unless CARB has issued an Executive Order as to such part or system.
WARNING: May contain items that are found to have compounds and/or chemicals known to the State of California to cause cancer, birth defects, and reproductive harm.
For more info, please visit https://www.P65Warnings.ca.gov.