The S58 3.0 inline-6 has already proven to be the most capable production turbo engine from BMW. It's still a relatively new engine in the G80 M3 and G82 M4. Flash tunes aren't even available yet, so this post may be a bit premature. However, we're too excited about the future of the BMW S58 engine with basic bolt-on upgrades. As new info is available in the future we will update this article. For now, let's jump in and discuss the basics to building a 700+whp S58 M3 & M4 with simple tuning and engine upgrades.
Best S58 Bolt-on Engine Upgrades
A few of the best mods for making massive power on the BMW S58 engine include:
These upgrades alone can take the S58 engine into the 700whp ballpark. As far as we're aware no one is making 700+whp on S58 M3/M4 stock turbos quite yet. However, they are still new engines and it's going to take time for tuning and other developments. RK Tunes already took a G80 M3 to 670whp. There are also a few 600+whp examples on low E85 blends without all of the basic bolt-ons.
We wrote about S58 tuning potential in this article. While the video is long - check out the Red Bull drift brothers linked in the previous article. They took the S58 to about 1,050hp with turbo upgrades and minor head work. This was done on PUMP GAS, so we're not even talking about race fuels or E85. Point is - the BMW S58 engine has massive potential.
Anyways, many won't push the S58 to its limits. 700WHP is serious power on stock turbos, and that will keep many entertained for a good while. It's a short list of mods to get the S58 3.0 twin turbo M3/M4 engine to those numbers. We'll break down the above S58 upgrades, and dive into some more mods and info at the end of the article.
S58 Reliability With High HP Mods
If 700whp sounds like a lot of power on a stock 3.0L engine block, internals, and turbos that's because it is a lot. How will all of these upgrades affect long-term reliability? Can the S58 really handle 700+whp? Fair questions. This kind of power with so few mods is nearly unheard of, and very few engines are capable of anything close to what the S58 can accomplish.
Again, it's still early for the G80 M3 and G82 M4. No one has exact data yet and even once info is out there it's never a perfect science. Time will certainly give us a much better idea. However, on paper, it seems like the BMW S58 engine is up to the challenge.
Check out the S58 tuning potential article since we talked about this topic a little bit there. If you dive into the specs of the S58 it's truly incredible. The engine is essentially a race-spec, emissions legal engine. Less the crank hub issues the older S55 is a pretty stout and reliable engine. This newer engine is a totally different animal. As of now, we suspect the S58 will still deliver excellent reliability and longevity even at 700+whp (with a quality tune, proper fueling, supporting mods, etc).
1. BMW S58 M3 & M4 Tuning
Flash tunes aren't quite yet available for the S58 engine in 2021+ M3 or M4 models. It will take time to crack to DME/ECU for flash tunes. Fortunately, piggyback tunes are a lot easier to develop quickly. Burger Tuning already has their S58 JB4 available in beta/testing stages. The JB4 is one of our favorite BMW tuning options, and we run them on all of our modded BMW's.
Anyways, tunes are the foundation to making big power. An S58 tune alone can offer power gains in the 70-100whp and 80-100wtq. Mix in some better fuels like E85 and power gains can exceed 125whp and 150wtq. More on this later when we discuss E85, race gas, and methanol injection.
It's also essential to have a tune to maximize the performance of other S58 upgrades like dual cone intakes and downpipes. We'll add more tuning info here once there are new developments and info. For now, we think the JB4 is by far the besting S58 tuning option.
3.0 Inline-6 Twin Turbo Tune Benefits
Some benefits of running a tune on the G80 M3 and G82 M4 include:
- 70-125+whp gains
- 80-150+wtq gains
- E85 compatible maps
- Control boost by gear
The benefits of an S58 JB4 tune are a lot more extensive than what's listed above. Of course, most will opt for a tune for the massive power and torque gains. As discussed, tunes also allow you to reap the full benefits of other bolt-on upgrades for the M3 & M4. Otherwise, there are tons of other performance, functionality, and other benefits.
JB4 tunes allow you to data-log and keep an eye on engine performance and data. You can set boost limits by gear, run E85 blends, and so much more. If you're looking for more power from the S58 a tune is definitely the best starting point. It's the single best bang for your buck mod.
JB4 Price: $799
Buy Here: BMW S58 JB4 Tuner
2. S58 Performance Intake Upgrades
Next up on the list of S58 M3 & M4 mods is a performance intake. Air intake upgrades go by many names like cold air intakes, performance intakes, and air intake systems. The list goes on and on. In the twin turbo BMW world many of us simply know intake upgrades as dual cone intakes (DCI). They're common intakes for good reason. Dual cone intakes offer excellent flow and sounds at a cheap price point.
Anyways, the purpose of S58 intake upgrades isn't to pull colder air. Temperatures at the intake have little to 0 effect on the intercoolers ability to cool the air. Open intakes - like DCI's - will pull slightly warmer air, but it doesn't have a negative impact on actual IAT's after the intercooler.
BMW S58 intake upgrades are simply intended to flow air more efficiently. After all, if you're making more power and more boost then you need to support the extra air-flow. Dual cone intakes are a popular option on twin turbo BMW engines, such as the N54 and S55. It's a proven system that's likely to be the go to choice on the S58 M3 and M4.
We're not aware of any DCI systems on the market quite yet, but some are in development currently. We'll have all the necessary updates once some products start rolling out.
S58 Dual Cone Intake Performance Gains
Running dual cone intakes on the S58 3.0L twin turbo engine offers the following performance benefits:
- Quicker turbo spool
- Turbo/induction sounds
Above is a dyno from Burger Tuning showing S58 power output. The second 609whp run was on a JB4 with an E30 fuel mixture. Last is 626whp with the same mods and the addition of their prototype S58 intake. Power gains of 15whp and 10wtq. Gains may be higher on more aggressive tunes, turbo upgrades, etc. However, on less aggressive tunes you may only pick up 5-10whp. Still, solid power gains.
You may also notice slightly quicker turbo spool with S58 intake upgrades. It will probably be minimal, though. Lastly, dual cone intakes really free up a lot of turbo and induction sounds. We think it sounds awesome on N54 and S55 engines, so we expect the same results on the G80 M3 and G82 M4.
DCI Price: ~$200-500+
Buy Here: Check back later!
3. S58 M3 & M4 Upgraded Downpipes
Downpipes are probably our favorite turbo engine modification outside of tuning. The S58 downpipes (DP's) bolt directly to the turbochargers and OEM parts feature restrictive catalytic converters or particulate filters. It creates a lot of back-pressure right behind the turbos. They're great for emissions reasons, but not so good for performance.
On turbo engines the rest of the exhaust system won't offer much power or performance gains. However, S58 downpipes should offer excellent horsepower. We're interested to see more info on power gains in the future. However, downpipes on engine like the N54 or S55 can offer about 10-25whp and 15-30wtq. We suspect results will be similar on the S58 M3 & M4.
This is also an excellent mod for engine and turbo longevity. Reducing back-pressure with upgraded downpipes helps lower temperatures. Less pressure also makes the engine and turbos job that much easier. All in all, S58 downpipes are a great upgrade to make more power and do so reliably. The downside is that exhaust mods may be considered illegal and fail emissions inspections.
BMW S58 Catless vs High-Flow Downpipes
We will have a S58 DP guide in the future that delves a lot deeper into this topic and more. However, it's important to quickly distinguish between catless and high-flow catted downpipes. The goal of downpipes is to reduce back-pressure. Catless options will do the best job at that and offer the best performance. They're also generally about 1/2 the price of high-flow cats.
However, catless downpipes will quickly fail emissions. Visual inspections won't work, either, since it will be visible the engine lacks the primary converters. High-flow catted downpipes will pass emissions in some states, but are still considered illegal (along with exhaust mods in general).
DP Performance & Power Gains
Benefits of downpipe upgrades for the BMW S58 engine can be extensive. A few upsides of DP mods include:
- Faster turbo spool
- Lower back-pressure, EGT's, etc
- Awesome exhaust sounds
Again, M3 & M4 results with downpipes are limited so power gains are still a bit up in the air. We suspect they'll be good for at least 10whp and 15wtq, though. You'll definitely pick up low-end torque and faster turbo spool thanks to lower back-pressure. Reducing this helps lower exhaust temps and is healthier for the engine and turbos.
You'll also notice more aggressive exhaust sounds on cold starts and heavy throttle. The nice thing about S58 downpipes is that the engine sounds stock-like once it's warmed up. You hardly notice a difference on warm idle or cruising around. However, dig into the throttle and the M3/M4 will offer a louder, more aggressive exhaust note.
Buy Here: Check back soon!
4. BMW S58 Fueling Mods
Our main focus here is on ethanol (E85) blends. However, fueling is a topic that's best covered from a holistic point. Running higher quality fuels on twin turbo engines can unlock a lot of power. E85 generally offers the most impressive gains, but race gas and water-methanol injection are other great options.
Ethanol offers so many performance benefits that it's tough to cover everything in one section of one article. Many understand turbo engines, like the S58, are very octane hungry. Full E85 has a rating of roughly 108 octane. It also burns cooler than gasoline and burns at a lower stoich. This means you need to flow more fuel, and that greatly reduces the chance of engine pre-detonations. However, it's also very demanding on the BMW S58 fuel system since it requires more flow. Back to this point in the next section.
Anyways, E85 is a high octane fuel that's very resistant to detonation. All of this means massive power gains for the S58 3.0L engine. Power gains on lower E30 or E50 blends can be in the ballpark of 20-50whp. Full E85 can make an extra 50-100+whp depending on S58 supporting mods. It may require some fuel system upgrades to get there, though.
*RK Tunes made 670whp on a G80 M3 with only a JB4, 100% E85, and some "secret RK sauce". They did install port injection for safety and headroom.
Fuel System Upgrades For E85
BMW S55 engines in the older M3 & M4 can run full E85 on stock turbos. However, it's really pushing the limits. The S58 engine receives a similar setup with dual high-pressure fuel pumps. However, it's a system rated for over 5,000psi - a huge upgrade over the S55's fuel system. We think the S58 will hold 650-700whp on 100% E85.
It might be pushing the limits if it's even possible. We always recommend building in headroom, so if you're shooting for big power on full E85 then it makes sense to consider port injection. These setups can be very expensive, and we'll have more info on S58 fueling upgrades as things develop.
S58 Supporting Mods & More Upgrades
We do have some general points to discuss in this section. However, this is just as much a place-holder for future topics and mods. Time will tell what or if any additional mods or supporting mods become commonplace on the S58 3.0 inline-6. Some other potential mods for the S58 include:
- Charge pipes
- Heat exchanger / intercooler
- Fuel system upgrades (port injection)
The list could go on and on. This articles primary focus is on the basic bolt-on mods to make 650-700whp on S58 stock turbos. We'll have tons more content coming in the future as the M3 & M4 aftermarket continues developing. Anyways, the above mods are some other considerations.
700+WHP S58 M3/M4 Summary
We did warn that this S58 upgrades article is a little premature. The G80 M3 and G82 M4 have only been out for about 6 months now, and there still aren't too many around. Despite it being so early the S58 is already capable of 650+whp on stock turbos with basic bolt-on mods. It's truly an incredible engine from top to bottom that has massive tuning and modding potential.
A tune, intakes, downpipes, and better fueling are the keys to making big power with the S58 M3/M4. These will become the most common mods, and will likely push many into the 650-700whp ballpark. With more tuning advancements, developments, and testing we believe we'll start to see some S58's making 700+whp on stock turbos. Throw on some upgraded turbos and it's likely 850-1,000+whp setups will show up.
This post will be updated as more data, info, and parts are available. We'll also have tons more content coming such as S58 upgraded turbo guides, fueling mod guides, and individual bolt-on upgrade guides. S58 engines are shaping up to be one of the most capable production engines in the world. We're excited for future developments, so check back for new S58 content!
Are you considering a S58 M3 or M4? If so, what mods are you planning?
Leave a comment and let us know!