BMW S58 Downpipes Upgrade Guide

The BMW S58 is an incredible engine capable of making 750+whp on stock turbos with basic bolt-on mods. Among the best bolt-on upgrades are a set of catless or high-flow catted downpipes. Upgraded downpipes help reduce backpressure and improve turbo spool, which results in impressive performance gains. In this guide, we discuss S58 downpipe upgrades including power gains, sound, catless vs high-flow, and more.

S58 Downpipe Performance Gains

• 15-25+whp gains
• 15-25+wtq gains
• Faster turbo spool
• Louder spool & exhaust sounds
• Lower backpressure
  • Less stress on engine & turbos

Lower backpressure should truly top the list as the biggest benefit of downpipes. It’s the reduction in backpressure that allows for the massive performance gains. The drop in pressure from pre to post-turbo plays an important role in a turbos ability to spool and build boost as the exhaust gases accelerate to escape to lower pressure air. Ultimately, a reduction in backpressure makes the turbos job easier and results in quicker spool, more boost, and more power.

Additionally, S58 DP’s help reduce stress on the engine and turbochargers. Moving the hot exhaust gases past the turbos and out of the exhaust faster helps lower exhaust gas temperatures and reduces exhaust gas reversion. Both great things for keeping the engine healthy and happy.

Upgraded S58 downpipes offer gains of roughly 15-25whp and wtq. Generally, gains will be on the lower-end with stock turbos and conservative tuning. However, those pushing the limits of the stock turbos or running upgraded turbos may see power gains of 25-30+whp.

Catless vs High-Flow Catted

Before buying S58 downpipes, it’s important to understand the difference in catless and high-flow catted options. Again, the main goal with downpipe upgrades is reducing backpressure. As the name suggests, catless pipes completely delete the catalytic converters (cats). It’s these cats that are the real issue in creating excessive backpressure.

However, you don’t need to delete the cats to still see performance gains and benefits. S58 high-flow downpipes replace the restrictive OEM cats with much higher-flowing catalytic converters. Basically, the cats are less dense which allows exhaust gases to pass through quicker.

S58 catless downpipes offer the biggest reduction in backpressure and the best performance gains. High-flow catted downpipes will offer slightly less performance with the benefit of remaining emissions legal. Catless downpipes are only intended for M2, M3, or M4 vehicles that are not road-legal or actively registered.

Downpipe Sounds

Downpipes offer a louder, more aggressive exhaust note primarily on cold starts and under heavy throttle. The S58 will also be slightly louder on a warm idle or while cruising, but the change in sound is very minor – especially inside the car. It’s a good balance as you’ll notice the turbo spool and exhaust at heavy throttle. However, the sound isn’t overly intrusive or droning for normal cruising and daily driving.

That said, things can start to get loud quickly if you modify the rest of the exhaust. It’s something to consider if you want a brutally loud and awesome M2, M3, or M4 exhaust note. However, if you’re worried about the S58 being too loud then it’s best to just stick with the downpipes.

As a final note – much like with performance – S58 catless downpipes will offer louder, more aggressive exhaust notes. High-flow DP’s still add some awesome noise, but since cats are still in place it will muffle a bit more sound.

Best S58 Downpipes Upgrades

With the background info out of the way, it’s time to talk about some of the best BMW S58 downpipes. Our main focus here is on downpipes that provide a great balance of price, quality, and performance. It’s hard to describe exact DP sounds with words, so if sound is your primary reason for downpipe upgrades is sound then check out some YouTube videos.

1) VRSF S58 Catless Racing Downpipes

As for any other modern turbo BMW engine, we highly recommend VRSF bolt-on mods. VRSF has been around since the early N54 days and they have proven to build quality products that deliver great performance at great prices. That’s no different for their S58 catless racing downpipes. They’re 3″ downpipes made from T304 stainless steel and feature mandrel bends and TIG welding.

VRSF downpipes also offer smooth bends and a full 3″ design to maximize flow and performance. Power gains with the VRSF S58 downpipes will generally fall in the ballpark of 20-25whp and 20-30wtq. For $569.99 these downpipes offer a great balance of price, performance, and quality.

The only downside is VRSF currently only offers catless downpipes for the S58. Again, these are only intended for off-road vehicles without an active registration. If you’re looking for high-flow catted downpipes then VRSF isn’t an option, but there are still tons of great DP’s available.

Price: $589.99

Buy Here: VRSF S58 Downpipes for M2, M3, M4

X3M & X4M Downpipes

2) MAD High-Flow Catted Downpipes

Mastery of Art & Design (MAD) offers high-flow catted downpipes featuring Euro5 200 CEL catalytic converters. They’re also made from quality T304 stainless steel and feature smooth bends for optimal flow. At $689 the MAD S58 downpipes are one of the best values for high-flow DP’s around.

ARM Motorsports is another great option for 200 CEL high-flow cats. They’re right around the same price as MAD and also feature quality construction like the previous two options. Ultimately, both MAD and ARM Motorsports are great picks for those interested in high-flow catted downpipes.

Price: $689.00

Buy Here: MAD High-Flow DP Upgrade