VRSF N55 Catless Downpipe Review: Best Value BMW Mod?

VRSF N55 Catless Downpipe Review: Best Value BMW Mod?

If you’re looking for an upgrade that truly transforms your BMW, you’re in the right place.

Today, I will be reviewing the VRSF N55 Catless Downpipe.

Having installed and tested this downpipe on my own BMW M135i, I’m excited to share my experiences!

Whether you want to boost your car’s performance or just want that aggressive exhaust note, this downpipe might just be the best value mod you can add to your BMW.

Let’s get started!

Overview: VRSF N55 Catless Downpipe

Let’s start with an overview of the VRSF N55 Catless Downpipe:

For those who may not be familiar, a downpipe is part of your car’s exhaust system. It connects the turbocharger to the exhaust, and its design and construction have a significant impact on your car’s performance and sound.

This particular downpipe is designed for N55 engines, found in various BMW models.

VRSF offers this downpipe in two variations: catless and catted.

The catless version, which I’ve personally tested, is all about maximizing performance. It is completely open from the inside:

Without the catalytic converter, exhaust gases flow freely, reducing back pressure and allowing your turbo to spool up quicker.

The result is a noticeable bump in horsepower and responsiveness.

The catted version offers a more balanced approach. It has a 200-cell high-flow catalytic converter, which allows for significant performance improvements while reducing emissions compared to the catless option:

The high-flow catalytic converter ensures that exhaust gases are cleaner, yet it’s designed to minimize the restriction of the OEM catalytic converter.

This means you still get a notable increase in horsepower and responsiveness, albeit slightly less than the catless version, but without the potential legal and environmental concerns.

While the catted version will still improve the exhaust note, it won’t be as aggressive as the catless version.

The VRSF N55 Downpipe is constructed from SS304 grade stainless steel, which is a type of steel known for its durability, resistance to corrosion, and ability to withstand high temperatures.

The downpipe is made with mandrel-bent tubing, which creates smooth bends and a consistent diameter throughout the pipe.

Smooth flow equals less turbulence, which translates to better performance.

Plus, the precision CNC machined flanges ensure a perfect fit, eliminating any worry about exhaust leaks.

Installing the VRSF Downpipe on a BMW M135i

Installing the VRSF downpipe is surprisingly straightforward, especially if you’re accustomed to doing some simple DIY jobs on your car.

In my experience, you can expect it to take about an hour, although this can obviously vary based on your experience level and work environment.

Firstly, remove the underbody panels to access the OEM downpipe.

Once exposed, you’ll notice the downpipe is held in place by metal clamps on either side, secured with nuts.

Over time, these can become quite stubborn due to heat exposure. If they’re resistant, a few persuasive taps with a hammer can loosen them up.

Here is a comparison of the OEM downpipe with catalytic converter and the catless VRSF downpipe:

Next, turn your attention to the O2 sensors. These components need to be transferred to your new VRSF downpipe.

With a 7/8″ (22 mm) wrench, you can detach the sensors. Handle them with care, as they can be sensitive.

Here is how the VRSF downpipe should look before the installation, with the O2 sensors and the metal clamps:

With the OEM downpipe disconnected, the installation of your VRSF downpipe is the opposite of the removal process.

Ensure that the metal clamps encircle the V-band flanges snugly for a leak-free connection.

Here is how the installed VRSF catless downpipe will look under your car:

8 Benefits of a VRSF Catless Downpipe

Still wondering why you should upgrade to a VRSF downpipe?

Here is an overview of the benefits it offers:

  1. Increased horsepower and torque. By removing the restriction of a traditional catalytic converter, the VRSF catless downpipe allows exhaust gases to flow more freely, reducing back pressure. This leads to a better turbo spool and an increase in both horsepower and torque. The car definitely feels stronger after the catless downpipe install. The OEM downpipe with catalytic converter is incredibly restrictive and I definitely believe when VRSF says that the downpipe adds an extra 20-25 horsepower with a tune.
  1. Louder exhaust sound. Another noticeable change after installing the VRSF catless downpipe is the sound. The catless downpipe makes the exhaust sound a tad louder, but it’s not huge if you leave the stock exhaust installed. The main difference is that the exhaust sound becomes a bit more raspy, and the pops and bangs are a little bit louder.
  2. Faster turbo spool. The reduced back pressure also contributes to quicker turbo spooling.
  3. Choice between catless and catted downpipe. VRSF offers both catless and catted versions of their N55 downpipe. If you don’t need the catted downpipe for emission regulations, I would recommend choosing the catless downpipe for optimal sound and performance.
  4. “No Hassle” satisfaction guarantee. Purchasing a VRSF downpipe comes with peace of mind with the “No Hassle” satisfaction guarantee. This assurance includes a promise of perfect fitment. If you encounter any issues or are not fully satisfied with the fitment or performance, VRSF is dedicated to resolving your concerns.
  5. Ceramic coating service. If you want to improve the performance of your VRSF downpipe even further, VRSF offers an optional ceramic coating service. This coating, made from Cerakote High Temperature Ceramic, is designed to withstand temperatures up to 1800°F. It provides an additional layer of protection against heat and corrosion. Additionally, it helps reduce heat transfer to the engine bay, potentially lowering intake air temperatures:
  1. Durability and longevity. Made from high-quality SS304 grade stainless steel, the VRSF catless downpipe is built to last. It’s resistant to corrosion and can withstand high temperatures.
  2. Lifetime warranty. VRSF believes in their downpipes so much that they offer a lifetime warranty!

Tip: If you like this review, also check my VRSF Intercooler review or VRSF Charge Pipe review!

FAQs about downpipes

Any more questions about downpipes? Check out these FAQs!

What does a VRSF downpipe do?

A VRSF downpipe replaces the restrictive factory downpipe in your BMW, allowing exhaust gases to flow more freely. This helps reduce back pressure, which can lead to faster turbo spooling, more power, and a more aggressive exhaust sound.

Are all N55 downpipes the same?

Yes, all F-series BMW models (1-, 2-, 3-, and 4-Series) with the N55 engine have the same downpipe. However, models produced up to 07/13 have a 3.5″ V-band flange inlet on the turbocharger side. Meanwhile, models produced after 07/13 have a 4.0″ V-band flange inlet on the turbocharger side.

How much horsepower does a downpipe add?

A VRSF downpipe can typically add around 20-25 horsepower when combined with a proper tune.

Does a downpipe hurt the turbo?

No, a downpipe doesn’t hurt the turbo. In fact, reducing the back pressure helps the turbo operate more efficiently. Just make sure the downpipe is installed correctly.

Can I run catless downpipes without a tune?

You can technically run catless downpipes without a tune. However, after some time, you will get a check engine light on your dashboard. You can get this removed by visiting a tuner or doing it yourself using BM3 or MHD Tuning.

What are the disadvantages of a catless downpipe?

The main disadvantage of a catless downpipe is that it increases emissions, potentially causing your car to fail emissions tests in regions with strict regulations. It also produces a stronger exhaust smell since the catalytic converter is removed.

Does a catless downpipe make the turbo louder?

Yes, a catless downpipe makes the turbo noises more pronounced. You will notice louder turbo spooling sounds and a more distinct blow-off noise when you let off the gas.

Does a catless downpipe make the exhaust louder?

Absolutely, a catless downpipe typically makes the exhaust sound louder and more aggressive. You’ll likely notice an increase in volume and a deeper tone, along with more pronounced pops and bangs if your car is equipped for that.


Alright, let’s wrap this up!

VRSF calls upgrading your BMW with a VRSF N55 Catless Downpipe the best bang-for-buck mod available, and I agree. Especially if you pair it with a tune!

The perks are clear: more power, quicker turbo response, a beefier exhaust note, and top-notch quality that’s built to last.

Plus, VRSF guarantees that you will be happy with your upgrade.

If you have any further questions, let me know in the comments below!

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