Some were pessimistic about the B58's tuning potential; especially after N55's took a step down from the N54. Fortunately, the B58 has exceeded the expectations of many. There are already a handful of B58 engines pushing into the 700-800+whp range. It makes sense the B58 is progressing quickly given the N54 and N55 helped the tuning and aftermarket scene. Nonetheless, it's still impressive. Look no further than an upgraded turbo to push the B58 into the 500-800+whp ballpark. In this guide, we will discuss some upgraded turbo options along with the expected power, risks, and cost of each.
*B58 Doc Race turbo kit pictured above
How Much Power Can the B58 Handle?
It's important to understand the B58's limits before diving into the upgraded turbo discussion. Though, it's challenging to put exact numbers on upper limits. The B58 is still a relatively new engine. It will take time and more B58's pushing 700+whp to roughly understand the limits. However, there are a few things we can make educated guesses about, referencing experiences from the N54 platform. Additionally, there are general concepts that apply.
First and foremost, torque is generally harder on engines. We're guilty of sometimes quoting limits in horsepower, too. Heck, we referenced wheel horsepower in the last paragraph. However, it's not the best way to quote an engines limits - torque is more appropriate. We know 600 wheel torque is a relatively safe limit on the N54. We also know the B58 is equally as strong - if not stronger - on paper. Additionally, B58's pushed beyond that mark seem to be faring well.
There are also many other factors at play. Where is the B58 making that torque? 600 torque at 2,500 RPM's would generally be tougher on the engine than 600 torque at 6,000 RPM's. Back-pressure, especially in the manifold, also plays an important role.
Regardless, we feel the B58 has plenty of strength to hold up at 600 wheel torque with proper tuning. There is of course still risk. Anyways, that's plenty of torque to build some seriously powerful stock engine B58's. Ultimately, for those looking to push the envelope we would recommend a built engine.
B58 Upgraded Turbo Setups
Alright, with that out of the way we'll jump into the more exciting stuff. Throughout this post, we'll break down the upgraded turbo setups based on the following goals:
- 500-600whp Upgraded Turbo
- 600-750whp Upgraded Turbo
- 750+whp Upgraded Turbo
We often recommend people leave a little headroom for their goals. As such, the power numbers we state for each turbo are generally an efficient top range. If you're looking to make a consistent 700whp then you probably don't want a turbo that's absolutely maxed at 700whp. Leave some room, but don't go too overkill. You also probably don't want a turbo capable of 900whp if you never plan on pushing beyond 600whp. That will simply introduce unnecessary lag.
The above points are just something to consider prior to buying an upgraded turbo. Know the goals for your B58 and opt for a turbo option that safely meets those goals.
500-600WHP B58 Turbo Upgrade
These power goals are pretty modest for the B58 engine. While the stock turbo can make nearly 500whp there are still many benefits to upgrading. A quality upgraded turbo should make 500whp with greater efficiency and reliability. Additionally, you should see more dramatic improvements on the top-end. We suspect the 500-600whp range is a great target for most.
The turbos in this section may sacrifice a small amount of spool in favor of the better overall power band and top-end. However, they're going to be the closest to OEM spool when compared to the larger turbos later in this post. Supporting mods will be less demanding. These setups will also keep you in a relatively safe power and torque range on a stock B58 engine. Overall, these turbos will extract more from the B58 without going too overkill.
Recommended B58 Supporting Mods for 500-600WHP
- Downpipe & Intake
- Custom tune
- Charge pipe injection for meth or E85
Not too bad of a list. An upgraded downpipe and intake are basic bolt-ons and many looking to upgrade their turbo likely already have these mods. Otherwise, a custom tune is highly recommended to dial in the setup. Due to fueling limitations, we recommend opting for the Fuel-It charge pipe injection (CPI) kit. This will allow you to run either meth injection or higher E85 mixes to meet fueling demands. We prefer E85 rather than relying on meth as fueling. However, either option is solid and will help extract the full potential of these setups.
500-600WHP B58 Turbo Upgrade Options
1. B58 Pure Stage 1 Turbo (450-500whp)
The Pure stage 1 turbo was developed pretty early on in the world of B58's. In 2016, they made 481whp and 437wtq with only an intake, JB4, and meth on regular 93 pump gas. These numbers aren't overly impressive given the stock turbo capabilities as of 2020. We're assuming Pure Turbos has tweaked the design since then, but cannot say with certainty.
Nonetheless, with downpipes and tuning advancements since 2016 we suspect the Pure stage 1 turbo is capable of ~500whp. Again, nothing crazy. However, they may be a solid option at only $1,195 for those looking to make the power with what should be a more reliable turbo at 450+whp.
2. B58 VTT GC Turbo (525-575whp)
As with Pure Turbo, Vargas Turbocharger Technologies (VTT) has been in the BMW turbo game for some time. A few months back, VTT showed the GC turbo making a consistent 590-600whp and torque. They were running some basic bolt ons with an upgraded HPFP on E50 fueling (no meth). Impressive results - especially at this price point. Also, the turbo eclipsed 500wtq at a mere 2800-2900 RPM's and spool should be even a bit quicker on the street.
Similar spool to OEM with peak power and torque coming in around 600 to the wheels is tough to argue with. It's likely they could be pushed a bit over the 600whp mark. However, as we mentioned earlier, we're quoting these a bit lower to allow for some headroom within goals. Anyways, the VTT GC turbo has shown promising results at a solid price.
600-750WHP B58 Turbo Upgrade
Some of the turbos in this section will begin pushing the upper limits of the B58 engine. Again, the limits still aren't fully known. However, there is no question pushing much past 600wtq is beginning to enter unknown territory. A lot of these turbos will still make big power on the top-end. Though, they're also capable of making impressive mid-range torque. Consider a built engine, limit torque, or accept the greater risk.
Additionally, venturing much beyond 600whp comes with other challenges. Putting the power down in lower gears won't be easy on street tires. Limited slip differentials will help, but they're not cheap. You may also be nearing or surpassing the limits of the factory 8AT. If you plan on launching your B58 then upgraded axles may also be in order. The list of supporting mods becomes much longer.
Recommended B58 Supporting Mods for 600-750WHP
- Full bolt-ons (DP's, intake, intercooler, etc)
- Port injection
- Built engine
- Extensive tuning*
Downpipes and an intake are highly recommend bolt-ons. An intercooler/heat exchanger may be debated since the OE cooling system is very capable. However, at over double the stock power output things will definitely get hot on repeated pulls. A CPI kit will likely still get the job done. However, we like the idea of full port injection, especially as you approach 700+whp. We touched on axles, wheels, and tires above; none of this is absolutely required. However, if you want to launch the car and successfully put the power down then they're highly recommended mods. The same can be said for the built engine. It's not required, but for engine safety we're more comfortable in recommending a built engine. Also, dialing in the tune is going to take some extensive effort and work.
600-750WHP B58 Turbo Upgrade Options
1. B58 Pure800 Turbo (600-700+whp)
Pure is making the article once again; this time with their Pure800 B58 turbo. Their own car managed a staggering 742whp and 608wtq. It was, however, done on some serious fueling mods. They were running E75 fuel and meth injection with an upgraded HPFP and port injection. We really like the results, though. These turbos held some serious torque on the top-end resulting in 742whp. If you're planning on making big power on a stock B58 this is exactly what you want. Peak torque is barely higher that the VTT GC's we previously mentioned - yet the Pure800's pick up an extra 140whp.
Pure Turbo makes some excellent quality products and the Pure800 comes at a very reasonable price point. With proper fueling and supporting mods this turbo is well suited to 600-700whp. Of course - as evidenced by Pure - they've got a bit of room on top of that too.
2. B58 Doc Race Top Mount Turbo Kit (650-???whp)
As you likely noticed, Doc Race turbo kits are not cheap. However, Doc Race truly builds some top of the line turbos kits. Rather than custom fabricating B58 turbos they opt to go with the big brands. This kit uses an EFR9174 turbo from Borg Warner. Their turbo kit also comes with all components for a complete install and conversion to the top-mount layout. It's still a newer offering so we don't have too many details. We do know Doc Race builds awesome turbo kits and once more of these are in use they will definitely perform.
The Borg Warner EFR9174 turbo is available in different sizes with the ratings of 600-1000hp. Doc Race put down 662whp and 572wtq with this kit. They're generally good at offering different size turbo options. As such, we suspect they will release some kits capable of 800-900+whp as the B58 progresses. The price may be tough to swallow. However, if you're familiar with N54 single turbos or other Doc Race products then you know their turbo kits do not disappoint.
3. B58 BigBoost Stage 3 Turbo Kit (700-800+whp)
BigBoost certainly made an impression with their B58 turbo kits. We believe they were the first to reach 700, 800, and 900whp with the B58. As with Doc Race, BigBoost uses turbos from the big manufacturers. This kit with the Master Power 6164 turbo made over 800whp. However, it was done on a built motor. We highly recommend following in those footsteps if you really want to push this turbo to the limit. We're not as familiar with BigBoost compared to some of the other companies we've listed. However, it's tough to argue with these results.
750+WHP B58 Upgraded Turbo
We'll skip the long spiel about built B58 engines and supporting mods. Reference the recommended supporting mods from the previous section. Instead of recommendations they now almost become requirements. If you don't upgrade up-front you'll end up doing it down the road anyways. If you launch an 800whp B58 it's not a question of if you snap an axle, but rather when you do. Same with the engine itself.
These are seriously powerful setups with highly capable turbos. It's definitely beginning to reach unknown territory. Not too many have ventured into the 750-800+whp range yet. It's mostly been limited to aftermarket companies and test cars pushing this limit.
750+WHP B58 Upgraded Turbo Options
1. B58 VTT GC+ (750-850whp)
Vargas Turbo Tech is also making another appearance on this list. They claim their GC+ turbos are good for 850whp. However, data and information is limited as they're a relatively new offering. A customer test car made 850whp and 893wtq on a dynocom. This was of course done on a built engine. We're not familiar with dynocom as the typical dynos are Mustang dynos and dynojets. As such, we're not fully confident in the numbers since we don't know how the dyno reads relative to others.
Nonetheless, it's a very promising result. Vargas has been in the industry for a while, so they definitely know what they're doing. We fully believe these turbos are capable of 850+whp, but we would like to see some more results.
2. B58 BigBoost Stage 4 Turbo Kit (800-900+whp)
Price: $3,750 - $4,050
As we mentioned previously, BigBoost is impressing with their highly capable turbo kits. This stage 4 kit also runs a Master Power turbo, but this time around it's a 65mm turbo. This kit just barely eclipsed 900whp, which is highly impressive. It took the N54 years and years to get to that kind of power. It's cool to see the B58 achieve this milestone so quickly.
Again, we're not too familiar with BigBoost. We do know their results are impressive and they're undoubtedly pushing the B58 platform forwards. This kit definitely isn't for the faint of heart. However, if you want to be a part of pushing the B58 forward then look no further.
B58 Upgraded Turbo Summary
In its young career, the B58 is already smashing expectations and improving leaps and bounds in the tuning world. An upgraded turbo is definitely a necessity to push the B58 to and beyond its limits. Given earlier B58's are just recently coming out of warranty we suspect things will progress even faster. Either way, an upgraded turbo is capable of pushing the B58 into the 500-900whp ballpark.
Before opting for an upgraded turbo it's important to understand your goals. Choose a turbo that safely meets your power goals, but don't get too excessive. Modest 500-600whp setups do not require too many supporting mods and can be had for a reasonable price. As we progress to larger, more capable turbos the supporting mods add up quickly. Again, we're truly impressed with the B58. There should be some exciting improvements and developments in the coming years. Mod away and have fun!