How to Build a 700HP+ BMW S63tu for Under $1,500

The BMW S63tu is a 4.4L twin turbo V8 found in 2012-2017 M5 and M6 models. It produces an astounding 560hp and 500 lb-ft of torque from the factory. Even better, like many BMW engines, the S63 is also underrated. Aftermarket dyno tests show the S63 around 530whp and 520wtq. Nor does it end there. Wake up this beast with a simple tune and bolt-ons. The S63 is capable of blowing way by the 700whp barrier on stock turbos.

S63tu Mods & Bolt-ons for 700+whp

Alright, here is the thing. S63 engines are absolute animals. Unfortunately, the S63tu is so good it leaves the DCT transmission in the dust. Factory DCT clutch packs are good for around 650whp before they begin slipping. A tune only S63 can push this kind of power. To go further, you may consider upgrading to Dodson clutch packs. The issue? Dodson clutch packs are going to run you a cool $4,000+. Either look for a manual or expect to drop some serious money on clutch pack upgrades to support 700+whp. Nonetheless, here are the mods to make upwards of 800whp:

• Tune
• Catless Downpipes
• Meth Injection
• Intake & Chargepipe Kit

That’s really all there is to it. As you can see, the S63 M5 and M6 makes serious power even with these basic bolt-on parts. If you’re on stock clutch packs then you may want to opt for tune-only. Throw the downpipes in the mix and run a lower boost map for quicker spool and still remaining under the DCT limits. We’ll discuss each of these mods throughout the remainder of the post.

This guide covers both the BMW M5 and M6. However, we also have a guide dedicated specifically to the M6 S63.

Spark Plugs & Ignition Coils

Before jumping into the actual S63tu M5 and M6 performance mods we must diverge to discuss important standard maintenance items. Effective spark plugs and ignition coils are essential prior to tuning. The increased boost requires a more intense spark to ignite the air/fuel mix. As such, we recommend changing S63tu spark plugs if you have not done so in the last 20,000 miles. Same deal for ignition coils with more than 40,000 miles on them.

OEM S63TU Spark Plugs

NGK 1-Step Colder Spark Plugs

OEM S63TU Ignition Coils

Tune only S63’s may opt for either OEM or NGK spark plugs. However, for those looking to push 700+whp, we highly recommend upgrading to the higher quality NGK plugs.

If you would rather consume this content via a video, check out our How to Build a 700+ WHP S63TU video below:

BMW S63tu Tunes

Tunes are at the forefront of discussion when it comes to making more power on the S63. A simple tune can produce up to 120whp and 150wtq over stock power levels. Additionally, a tune is required to reap the full benefits of any other S63tu bolt-on mods. For under $1,000, the power gains are insane.

S63tu Flash Tunes vs Piggyback Tunes

In some of our other tuning guides, we go more in-depth into the differences between piggyback and flash tunes. We’ll give a brief overview. However, it’s less important to cover with the S63. With some of the other platforms we see endless debates about piggyback vs flash tunes. Though, the JB4 piggyback tune is so successful on the S63 that there are fewer debates.

Flash tunes re-write the DME. They change all tuning parameters from fuel flow to ignition timing. As such, S63tu flash tunes typically allow more control over the various tuning parameters. On the contrary, S63tu piggyback tunes are basically advanced boost-controllers. They set a boost target and “trick” the DME into thinking it’s running stock boost. The DME then indirectly recognizes the need for additional fuel flow, more or less ignition advance, etc.

Ultimately, we recommend opting for the S63tu JB4 piggyback tune. Piggyback tunes do have their limits. Fortunately, stock turbo S63’s will not exceed such limits. However, if opting for upgraded turbos we recommend running the JB4 stacked with a back-end flash tune.

1) BMW S63tu JB4 Tune

We love the JB4. Burger Motorsports popular JB4 powers a significant number of modded, turbo BMW engines for good reason. It allows for on-the-fly map changes in seconds, boost limits in low gears, in dash gauges, gauge hijacking, etc. Point is, the S63tu JB4 is loaded with awesome features. Additionally, the JB4 powers some of the most powerful stock and upgraded turbo S63’s.

The JB4 alone adds up to 120whp and 150wtq on the S63tu engine. For a mere, $700 it’s hard to argue against the JB4. Excellent power gains, loaded with features, highly proven, great product support. The list goes on and on. Great mod for all S63tu powered M5 and M6 BMW’s.

S63tu JB4 Price: $699 (optional $35 wired connection or $140 wireless smart phone kit)

S63tu HP & TQ Gains: Up to 120whp and 150wtq on tune-only S63’s

Buy Here: BMW S63tu JB4 Tune

2) BMW S63tu Flash Tunes

Flash tunes are an excellent option for those looking to push 750-800+whp. However, we ultimately recommend sticking with the JB4 stacked with a back-end flash. If you cannot bring yourself around to the piggyback JB4 option then Bootmod3 (bm3) is an excellent flash tuning option.

Like the JB4, Pro Tuning Freaks S63 bm3 flash tune comes loaded with excellent features. However, it comes it a bit pricier at $895. Additionally, some opt for custom flash tunes when going this route. Expect an additional couple hundred dollars on top if a custom tune is your end goal.

S63tu bm3 Price: $895 (additional if opting for custom flash)

S63tu bm3 HP & TQ Gains: Up to 140whp and 160wtq on race gas maps

BMW S63tu Catless Downpipes

Below is a quick rundown on S63 downpipe upgrades. We also have full guides for upgraded S63 downpipes and F90 M5 downpipe upgrades.

Catless downpipes are an excellent mod for the S63tu M5 and M6 engine. Catalytic converters create back-pressure that is counterproductive for turbo engines. Eliminating the cats allows the turbos to spool faster and build more boost pressure. They also help hold more boost on the top-end of the rev range. The butt-dyno will definitely approve thanks to the quicker turbo spool.

We recommend going with VRSF catless downpipes as they provide an excellent balance of price and quality. Expect gains up to 40-50hp. Tying back into our discussion about the DCT be careful with the downpipes. A tune and catless downpipes may put you well past the “safe” limits of the DCT. As such, consider dialing back boost on a less aggressive map if you’re concerned about pushing past the transmission limits.

VRSF S63 Catless Downpipes Price: $599

S63 VRSF Catless Downpipes HP & TQ Gains: 40-50whp & 45-60wtq

BMW S63tu Methanol Injection

Normally, we recommend modded BMW’s run E85 mixes. However, it’s not quite as straight forward on the S63 due to fuel trims. Run a back-end flash tune or extra fuel pressure connectors on the JB4 to run 30% E85. Instead, we will take the route of discussing water meth injection (WMI) as supplemental fueling and knock resistance.

Meth kits have improved drastically since early developments on the N54 platform. Though, we should still note meth injection comes with its own risk. We do NOT recommend meth injection without additional research. Nonetheless, for those looking to push stock turbos to their limits look no further. Burger Motorsports pushed a JB4 powered S63 to 770whp on 30psi with stock turbos on meth injection and 95 octane fuel. Certainly impressive numbers on stock turbos.

S63TU BMS Meth Injection Price: Starting at $429

S63TU Meth Injection HP & TQ Gains: 50-70whp and 60-80wtq

Buy Here: BMW S63tu BMS Meth Injection Kit

BMW S63tu Intake & Chargepipe Kit

While the performance benefits of the S63 dual cone intakes can be debated, we believe it’s worth it for the sounds alone. Peak power gains may not appear overly impressive with the intakes. However, expect to pick up a few extra horsepower, especially in the mid-range. Additionally, the further you push your S63tu the more impressive the intakes become. You may only net a few horsepower with a tune-only. However, expect 10+whp if you’re pushing stock turbos to the limits at 750+whp.

Note – the chargepipe (CP) does not provide any power benefits. However, it’s a good preventative mod to have. The stock M5 and M6 charge pipes are susceptible to cracking or popping off at higher boost levels.

S63tu Intake & CP Price: $599

S63tu Intake HP & TQ Gains: 5-15whp and 5-15wtq

Buy Here: S63 Intake & CP Kit

BMW S63tu Tuning & Modding Summary

There is no denying the S63tu is one heck of a performance engine. This 4.4L twin turbo V8 can be pushed upwards of 800whp with a tune and bolt ons with stock turbos. Those are truly insane numbers. Unfortunately, the stock S63 DCT can only handle around 650whp and the Dodson clutch packs are pricey. Nonetheless, there is no shame in making 650whp with a $700 tune only.

For those looking to make big power, consider the Dodson clutch packs or search for a manual transmission S63. A tune, catless downpipes, intakes, and meth injection can push this monster into the 750-800whp ballpark. These are power numbers most of us can only dream about. For the S63 M5 and M6, it is reality. Mod away and enjoy!

What are your thoughts on the S63tu?

Too much power? Check out our N63 500+whp post