SKU: 54716119246

Competition Series 4.5" Catless Downpipe for the B58 (6 Cylinder) Engine

Sale price$245.25 Regular price$272.50
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Ships within 48 hours · Estimated delivery Aug 11 - Aug 16

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Description

Competition Series 4.5" Catless Downpipe for the B58 (6 Cylinder) EngineOur new Competition Series 4. 5" Downpipes for your 2016+ 240i 340i 440i 540i, 2015+ 740i 840i, 2017+ X3 X4 X5 X6 X7 M40iX & Z4 M40i six cylinder B58 turbo engine! Key Features: Made in the USA! Manufactured in house. Fitment for the new BMW B58 Engine Higher Max Horsepower Power Curve Higher Initial Torque Curve. Torque curve hits faster, higher, and longer Better throttle response and faster turbo spool up times Mandrel Bent 4. 5" piping. Smooth

Our new Competition Series 4.5" Downpipes for your 2016+ 240i/340i/440i/540i, 2015+ 740i/840i, 2017+ X3/X4/X5/X6/X7 M40iX & Z4 M40i six-cylinder B58 turbo engine!

Key Features:

  • Made in the USA!  Manufactured in house.
  • Fitment for the new BMW B58 Engine
  • Higher Max Horsepower Power Curve
  • Higher Initial Torque Curve.  Torque curve hits faster, higher, and longer
  • Better throttle response and faster turbo spool up times
  • Mandrel Bent 4.5" 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
  • Brush Finish (standard) or optional Polish 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

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 4.5" Catless Downpipe, more power is unleashed!  You will feel the difference instantly. While the 32whp and 16wtq gains are awesome, one of the best aspects of the downpipe is that the gains are not just peak gains. Examine the dyno graphs and you will notice the powerband shifting to the left. What this means is that turbo lag is reduced with power coming on faster. Gains are throughout the powerband as well. Your car will feel like a totally different beast. As if it had woken from it's sleep!

SO WHY 4.5" PIPING? The new turbochargers on the B58 engines utilize a much larger 4.5" outlet compared to the 4" outlet on the older N55 engines. If we ran a 4" downpipe flange inlet so that we can use 4" tubing, a "step" would be formed between the turbocharger outlet and downpipe inlet. Exhaust gas for the turbocharger would hit this "step" and a lot of turbulence would form at this point and cause backpressure. Backpressure this close to the turbocharger would greatly affect performance. Thus, to ensure that we get unobstructed flow from the turbocharger outlet to the downpipe inlet, we had to CNC machine a new 4.5" flange to match. This allows a seamless transition and eliminate any possible turbulence which would cause backpressure. Though this presented another challenge for us as 4.5" tubing is not readily available and hard to source. Our motto "Performance, No Compromise" prevailed at the end and through hard diligence and many phone calls, we finally found a source for the material.  Even though the material was considerably more expensive than standard 4" stainless steel, we wanted to give our customers the best by producing the best product possible.

Our Competition Series Catless Downpipes 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 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 4.5" and the factory exhaust system is 3", the factory downpipes reduces size using short transitions from 4.5" before the catalytic convert and 3" afterwards. Due to space needed for the catalytic converter, the factory downpipes reduce in size using very short transitions. Since our catless downpipes delete the catalytic 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. Also, since we utilize a larger 4.5" pipe right after the turbocharger, turbo backpressure is significantly reduced. This results in less exhaust turbulence and backpressure which again improves throttle response and increase turbocharger spool times (less turbocharger lag). 

Our downpipes are designed to fit perfectly with either the factory exhaust system or your aftermarket exhaust system. There are no compatibility issues whatsoever.  The downpipes will come by default in Brushed Finish.  We also offer a Polished Finish as an option.

OPTIONS

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 absorption 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 additional corrosion resistance. We utilize the best ceramic coating possible. Our thermal coating can resist up to 2000F of heat. It is available in black only (all the other colors cannot withstand the high levels of heat).

Additional O2 Sensor Bung - An additional O2 sensor bung can be added so that you can easily add a wideband O2 sensor and gauges for you to 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.  This is not required for a normal standard installation.

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.  This is not required for a normal standard installation.

CAUTIONThis product is intended for OFF ROAD COMPETITION USE ONLY. Not legal for use on pollution controlled vehicles upon public road/highways. THIS PRODUCT IS FOR SALE FOR ALL 49 STATES EXCLUDING CALIFORNIA.  In addition to vehicle use verification, a Vehicle Compliance Waiver needs to be signed.

THIS ITEM IS NOT FOR SALE, INSTALLATION, OR USE ON LICENSED VEHILES IN THE STATE OF CALIFORNIA. 

The item is for sale for international customers without restriction.

Please contact us at [email protected] or call us at (626) 334-6609

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 54716119246

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Donna A.
Massapequa, US
★★★★★ 5
Very comfy sheets, nice fabric
Size: Full, Color: Oatmeal
I wasn’t expecting such good quality forthis price. They’re very soft, but of fairly thick fabric. I’m sleeping great on them. The pockets are deep enough for an 8” foam mattress plus my 3” topper. Will be getting another set for the second bedroom.
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H. Simon
Omaha, US
★★★★★ 5
Great Sheets!
Size: Twin, Color: Oatmeal
Super soft, wash up beautifully, seem well made — very happy! It’s very hard to find 100% cotton t-shirt type sheets and these are really lovely.
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Chris
Louisville, US
★★★★★ 3
Weirdly textured
Size: King, Color: Dark Gray
I have bought and loved jersey sheets in the past, that have all been as soft as a well worn cotton t-shirt. These arent soft. They have the stretch of jersey, but not the soft smooth texture that they should have. Even after washing a few times these are one of my least favorite sheets I've ever bought on Amazon.
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Reviewed in the United States on May 30, 2026
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Nyfan1
Grantham, US
★★★★★ 5
Soft, Breathable Sheets That Feel Great to Sleep On
Size: Twin, Color: White
This Amazon Basics jersey sheet set was a really good purchase. The cotton material is soft, stretchy, and breathable — it feels like sleeping in a comfortable T‑shirt. The fitted sheet has a nice snug fit that stays in place, and the flat sheet is lightweight without feeling flimsy. The fabric washes well, doesn’t pill, and stays soft after multiple loads. It’s a great everyday sheet set for anyone who likes that cozy, relaxed jersey feel. Overall, comfortable, easy to care for, and great value for the price.
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Christopher
Boise, US
★★★★★ 5
The Perfect Sheets To Lie On While Writing Amazon Reviews
Size: Full, Color: Light Gray
As I write this, I am laying on an adjustable full sized bed by Hofish and a 10.5" comfort foam mattress by Classic Brands. I know I sound like I am an Amazon plant, but I swear I am not. I'm not even a stockholder anymore. This is the most awesome bed stylings combination I have had in many, many years. In fact, it is the best I have ever owned and it is beat only by some ritzy resort I stayed at on vacation like 20 years ago, though I admit I was pretty drunk the entire time so my memory might not be the most accurate. But getting back to today... these sheets are great. I washed them twice - I'm not a neat freak, I am just amazingly disorganized and easily distracted while doing laundry, so tonight they went though two wash cycles and one dry. And then I put them on the bed. While these sheets are not deep pocket sheets, they don't need to be with this mattress. There is enough room and border for them to tuck and wrap with the elastic to give a strong grip under the mattress, which is important as the adjustable frame continually put the sheets and mattress though its repeated adjustable calesthenics-type positioning. The other two sheet sets I have used since I got this bed have struggled poorly with this. In the day or so and at least a dozen position changes, these sheets stay in place with no popped corners to exposing the bowl as the head and feet rise. Of course, till will tell if it lasts, but so far they are the best of the batch of sheets in my closet. As for texture, they are awesome. I'm a dude. I don't really know what thread count or knit or whatever really means. But these sheets feel like a well-washed favorite, quality rock & roll concert t-shirt. And not one of these glitter puff stupid new groups, like a real rock band from the 80s that now charges $250 for a concert ticket and $60 for a t-shirt...but that group you saw back then, paid $10 for the shirt and you STILL have it and love to wear it because it is perfectly molded to your body, soft and reliable. The kind of shirt you will wear under your suit at work and just grin not just for mental middle finger to corporate dress codes, but because the t-shirt is just that great of a feeling. Well, that is what these sheets feel like. And now you get to sleep in it. It is that awesome. In LA right now we are having a nasty heat wave, but these sheets don't seem to bake me even with my stuttering AC. The flannel sheets I love seem to trigger the butt sweats as soon as I lay down in this heat, but no such problem with these. So really, I'm absolutely happy with these things. I am going to order more in other colors as soon as Amazon gets them back in stock. Great price, great quality, great comfort, great fit, great deal. It is that simple.
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Reviewed in the United States on September 3, 2017

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