BMW N54 engines have long been known to deliver great performance with a few basic bolt-on mods. Simple bolt-ons for the N54 can push the engine to 400-450+whp with relative ease. Downpipe (DP) upgrades are among the best mods to take the 3.0L twin turbo engine to the next level. In this guide, we compare N54 catless and catted downpipes, discuss pros and cons, and list some of the best DP upgrades.
BMW N54 Downpipes Upgrade Performance
Catalytic converters (cats) are an important part of an exhaust system to help reduce emissions. They're great for that reason. However, cats are very restrictive which leads to worse performance. The pressure drop from pre to post-turbo is essential for spooling the N54 twin turbos. Therefore, reducing back-pressure after the turbos helps with faster spool and building more boost.
Removing the entire exhaust system would offer the biggest benefits. However, that's not the most reasonable proposal. Upgraded N54 downpipes are the next best option. DP's offer the best gains compared to the rest of the exhaust since they bolt right up to the turbos. Catless and high-flow catted downpipes are an excellent way to reduce back-pressure and free up plenty of power.
N54 Upgraded DP Pros
- 15-25whp (10-15whp w/ catted DP's)
- Similar torque gains
- Quicker turbo spool
- Better top-end power
- Exhaust sounds
The big power and torque gains are likely the top selling point. Power gains depend on many different factors, so not everyone will pick up 15-25whp. Regardless of exact N54 hp gains downpipes remain one of the best bolt-on mods. They offer so many different benefits for a low price. Quicker turbo spool and better top-end power are two notable benefits. Another important one - DP's are generally easier on the engine and turbos. The reduction in back-pressure helps lower WGDC, get rid of heat faster, etc.
Catless and high-flow downpipes with cats will provide similar benefits. Though, catless N54 DP's are the best bang for your buck option. They offer more performance and generally cost less.
Cons of Downpipe Mods
Both catless and high-flow catted downpipes are generally illegal. High-flow catted downpipes may pass emissions in some states, but tampering with OE emissions equipment may still be illegal. N54 downpipe mods are really only intended for off-road use.
That said, high-flow cats are the best option for those concerned with emissions. They are more likely to pass emissions and visual inspections. Those running heavy E85 mixes may still pass emissions with catless. However, the visual inspection will fail due to the lack of cats in the downpipes.
N54 Catless DP's Sound
Last quick topic before moving onto some of the best N54 downpipes. Sounds with exhaust mods may be a concern to some. DP's offer a deeper aggressive note while under heavy throttle. You'll likely hear a little more turbo noise, too. Cold starts will also be quite a bit louder than stock.
However, once the N54 warms up the downpipes are hardly noticeable. Idle inside the car will sound stock. Moderate cruising and driving will result in OE-like sounds as well. Dig into the throttle, however, and the exhaust wakes up and will be a decent bit louder than stock.
Catless downpipes will generally sound louder than high-flow cats. We think it's a good balance of sound if you leave the rest of the exhaust stock. Deeper, more aggressive note when you want it under heavy throttle. Otherwise, we believe most N54's sound stock while cruising or idling once warm.
Best BMW N54 Downpipes
Alright moving onto a few of the downpipes we believe are the best options for the N54 engine. Please note - this is by no means an exhaustive list. The N54 has been around for a while, and there are tons of downpipe mods available. However, these are a couple options that we believe provide a great balance of price, quality, and performance.
1. VRSF N54 Downpipes Upgrade
We're big fans of bolt-on mods from VRSF, and almost solely run their products on a few of our N54 engines. VRSF's balance of price, quality, fitment, and performance are tough to match. They've sold thousands of upgraded downpipes for the N54 135i, 335i, 535i, Z4, etc. That means they're also a highly proven choice with a great warranty to back the DP's. VRSF offers a lifetime warranty against any defects or fitment.
They also offer both catless and high-flow cat options for the N54. High-flow options come at an additional cost, but they're very well priced compared to other catted options. As with almost any N54 catless downpipes, expect power gains in the ballpark of 15-25whp. It's really hard to go wrong with N54 VRSF DP's.
Price: $269.99 ($429.99 for high-flow cats)
Buy Here: BMW N54 VRSF Upgraded DP's
2. Turner Motorsport 3" High-Flow Catted DP's
Turner Motorsport offers a 3" high-flow option for BMW N54 downpipes. They're a bit pricier than VRSF, but still a fair price for catted downpipes. This options been around for quite some time, so it's another good option all around.
Ultimately, we find it hard to recommend much other than the VRSF options. There are cheaper options out there, bigger brand names, etc. However, we believe VRSF offers too good a balance between price, quality, performance, etc.
Anyways, these Turner high-flow N54 downpipes are a solid option for a fair price. If you're not sold on VRSF then these make for a great choice.
BMW N54 Downpipe Upgrade Summary
Downpipes are one of the best basic bolt-on upgrades for the N54 twin turbo engine. Aside from a tune they were our favorite mod since DP's offer so many benefits for a great price. Power gains of 15-25whp are likely enough to convince most people. However, the benefits don't stop there.
N54 DP upgrades offer faster spool, better top-end power, and are generally easier on the turbos and engine. All of these pros do come with the downside of legality concerns for street-use N54's, though.
We believe VRSF offers the best all-around N54 downpipes. Their balance of price, quality, performance, and proven results are tough to match. However, the N54 is an old engine with lot's of aftermarket options available.
What N54 DP's do you run? Which are you considering?
Leave a comment and let us know!