How to Build a 500+WHP BMW N63 for Under $1,500

BMW has shown their commitment to the BMW N63 engine. It was first released in 2008 and remains in production as of 2020. The twin turbo 4.4L V8 N63 received a few updates along the way. 2012 saw a large improvement (N63TU) with the addition of valvetronic, revised turbos, lighter pistons, forged rods and crank, etc. Once again, in 2016 the engine was updated and coined the N63TU2. This time around the N63 received twin-scroll turbos. Finally, in 2018 it received larger twin-scroll turbos and a fuel injector upgrade, to name a couple.

With all of these updates, the most powerful N63 variant is making 523hp and 553 torque straight from the factory. Highly impressive. However, it doesn't stop there. Even the early model N63 engines can eclipse 500whp with a few simple bolt-on mods. Later models with the larger turbos and better fueling may see power in excess of 600whp. In this guide, we will examine the tunes, mods, and bolt-ons to launch your N63 to 500-600+whp.

BMW N63 N63TU and N63TU2 Mods

As stated above, a tune and a few simple, cheap bolt-ons can push the N63 to 500-600+whp. Tunes are typically the starting point for modding the N63. A mere $600 tune alone may unlock up to 100whp. Mix in some bolt-ons and you've got a car pushing upwards of 150+whp over stock. The most common and beneficial mods include:

  1. Tune
  2. Air Intake (more for sound - not big power gains for the $)
  3. Catless Downpipes
  4. Upgraded Intercooler
  5. E85 Fuel

As these are basic bolt-on mods, even novice DIY'ers can tackle most of the above items. Without further ado, let's break down these mods one by one to take your BMW N63 50i to the next level.

1) BMW N63 JB4 Piggyback Tune

Whether it be the N63 or any other turbo BMW engine, we highly recommend Burger Motorsports (BMS) JB4 piggyback tune. The JB4 is loaded with awesome, unique features. Data logging features, on the fly map (tune) changes, adjustable fuel control, boost by gear, meth injection support, etc. The list goes on and on.

Additionally, the JB4 is quick plug and play installation. It is compatible with E85 mixtures and allows the use of back-end flash (BEF) maps. BEF tunes can be stacked with the JB4. This enables users to design custom tunes to their liking while maintaining all of the JB4's features. BMS also offers excellent customer support as an added benefit.

We really don't have a bad thing to say about the JB4. Combine that with horsepower gains of 100+whp and it's hard to go wrong with the JB4.

N63 JB4 Cost: $599

N64 JB4 HP Gains: 80-120whp (tune only. Depends on specific N63 variant)

Buy Here: BMW N63/N63R/N63TU JB4 Tune

2) BMW N63 Performance Air Intake

For most turbo BMW engines this is our second recommended mod following a tune. Although, in the case of the N63 this mod may not be worth it to some. The OEM intake design on the N63 is very efficient. Performance air intakes only offer performance benefits if the engine is struggling with air flow. This should not be an issue on a stock turbo N63.

Although, a performance intake may add a few horsepower for those pushing stock turbos towards their upper limits. Regardless of power, the intakes are almost worth it for the sound alone (open intakes/filters). If they were a couple hundred dollars we would absolutely recommend them for sound. However, most of the N63 intakes range from about $500-$1,000+.

It's a lot to spend to hear some louder turbo noises and maybe gain a few horsepower. They do sound phenomenal though.

N63 Intake Cost: $447+

N63 Intake HP Gains: 0-5whp

Buy Here: BMW N63 Performance Intake

3) BMW N63 VRSF Catless Downpipes

Catless downpipes (DPs) are an excellent mod to extract massive power from the N63. Catalytic converters in the OEM downpipes are simply too restrictive for the N63 turbos. The drop in pressure from pre-turbo to post-turbo plays an important role in a turbos ability to spool and build boost. Too much back-pressure after the turbo results in additional turbo lag.

Remove the cats from the DPs, and the turbos are able to reach their full potential. Not only does this result in impressive horsepower gains, but the turbos also spool much quicker. Your butt-dyno will approve of this mod, and it may even make the car feel faster than the tune did. Power gains of 50+whp are possible on the N63. When combined with quicker spool and instant torque the catless downpipes are truly an excellent mod.

It doesn't end there, either. The big question remains - are catless downpipes too loud? The simple answer - no. Your N63 will sound louder on cold starts and develop a deeper, aggressive note under full throttle. However, catless DPs are hardly noticeable cruising on the highway or around town. Emissions testing is definitely one drawback, though.

N63 VRSF DPs Cost: $450

N63 VRSF DPs HP Gains: 40-55whp + quicker spool and massive torque

Buy Here: BMW N63 VRSF Catless Downpipes

4) BMW N63 Intercooler Upgrades

We'll keep this short as, unfortunately, there are not many options. However, the stock intercoolers on the various N63 engines are pretty efficient as is. Alpina and Dinan offer some aftermarket intercooler options. The downside? Alpina intercoolers are tough to track down, and Dinan is a fortune.

Upgraded intercoolers generally do not offer significant performance benefits for moderate driving. A few full throttle pulls with time to cool down between suffices. Although, the stock intercoolers can become overwhelmed from tracking and/or extensive full throttle pulls. This causes some power loss as IAT's increase and the engine becomes "heat soaked".

We recommend avoiding intercoolers on the N63 platform, unless you are really pushing the engine to its upper limits. The benefits simply do not justify the cost.

5) BMW N63 E85 Mixtures

E85 mixtures are highly recommended not only for the N63, but also for any performance engine. E85 has countless benefits, especially when pushing the N63 past stock boost levels. First, it burns cooler than gasoline. This results in lower temperatures within the cylinders. Second, it burns at a stoich of 9.765 compared to 14.7 for gasoline. As such, more fuel must be injected into the cylinder.

Cooler burn and more fuel result in a lower chance of knock or pre-detonation. This allows the N63 to run more boost and possibly more aggressive ignition timing. Therefore, E85 is generally safer for the engine, runs cooler, and adds power. All great things.

E85 also has a few downsides that should be noted. Fuel efficiency decreases (though it should even out given the lower cost of E85 vs 91/93 octane). Your tune must also compensate for the E85 mix. The JB4 tune is able to accommodate up to 30% E85. Anything higher would require the use of a back-end flash tune.

N63 E85 Cost: ~Same price as 85/87 octane gas (lower fuel economy)

N63 E85 HP Gains: 10-50whp (depends on tune and specific E85 mix)

BMW N63 500+WHP Supporting Mods

While the N63 comes from the factory ready to make 500+whp with some basic bolt-ons, there are a few "supporting" mods that should be mentioned. Unlike most other turbo BMW engines, the stock charge pipe is surprisingly not much of an issue. As such, we'll skip that and discuss a few basic items.

1) BMW N63 Spark Plugs

Again, unlike most turbo BMW engines, the N63 runs well on OEM spark plugs. We do recommend upgrading to 1-step colder spark plugs on modded N63's, but it is not required. However, a tuned and modded N63 will still burn through spark plugs rather quickly. Prior to modifying your N63, we recommend replacing spark plugs if it has not been done in the past ~30,000 miles. Once tuned, it is advised to change the spark plugs every 15,000-30,000 miles.

BMW N63 OEM Spark Plugs

BMW N63 1-Step Colder Spark Plugs

2) BMW N63 Ignition Coils

Similar to spark plugs, a tuned N63 will develop a habit of eating up ignition coils. We advise replacing every 25,000-40,000 miles on a tuned N63. You may consider replacing them prior to tuning and modding.

BMW N63 OEM Ignition Coils

BMW N63 500+WHP Summary

The N63 is quite unique compared to most other turbo BMW's. Coming from the inline 6 BMW engines we are so used to upgraded intercoolers, charge pipes, and air intakes being the norm. However, the N63 is a bit different. Intercoolers and air intakes generally do not provide enough benefit to justify the cost. However, they may be necessary or beneficial for those looking to push stock turbos to their upper limits or opt for upgraded turbos.

Otherwise, a tune, catless downpipes, and E85 mixtures are enough to thrust the N63 to 500-600+whp. Definitely an impressive accomplishment for the N63 engine. These basic mods can be had for right around $1,100 and truly take the N63 to, and beyond, the next level.

Check out our post about the 5 most common BMW N63 problems.

What are your thoughts and experience with the N63? Drop us a comment and let us know!

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7 thoughts shared

  1. Comment author image

    Jameson kilpatrick

    says:

    If you want the fastest most reliable tune you go to heatsync performance euro also known as H.P.E. Tuning they have put cars with downpipe intake and tune only into the 10s and they have gotten my 7 series moving out I have 12k miles with the tune and not a single issue I have everything on this write up plus some HEATSYNCPERFORMANCEEURO.com

  2. 2014 x5 5.0 (4.4) – 630+ HP
    I up sized the air filters to the F85 X5M which just about doubles surface area of the air intake at the same time I flashed BM3 (BootMod 3) stage 1. This mod unleashed a lot of power on the car and really made it feel strong. The stock plugs were in need of immediate replacement after the mod as I would get some misfires or stumbling under heavy load.
    After that mod, I went another step colder on the plugs, installed the VRSF catless downpipes and upgraded to BM3 stage 2, 93 octane. OMG this SUV is a beast! Not many cars can match the acceleration which is near 3.1 zero to 60 with launch control with 630+ hp
    I just added the xHP transmission mod as the final mod I will likely do on the beast. Now it has much fast shifts which are quite noticeable. Fast enough to improve acceleration times even further.

    The catless downpipes were a huge win for improving power, but more importantly very noticeable turbo spool speed is much faster. I wasn’t sure if it would be that noticeable but it you notice immediately. Since i have no cat’s I enabled cold start delete so the cold engine doesn’t rev. I have to think this is better for long term reliability of the engine.

    The downpipes allow you and other drivers to hear the turbos spool up quite easily (they’re almost silent when stock), then the engine roars and sounds like a race car to the people you pass with their windows open. It’s not too loud with very moderate sound levels, especially when just cruising.

    This SUV is a sleeper with massive power on tap at any speed. I don’t know about the JB4 mods, but the BM3 is awesome when coupled with the downpipes. I highly recommend the BM3 with catless downpipes for an awesome bang for the buck.
    And yes, it’s faster than an X5M and an M3

  3. How restrictive are the stock DPs on their own? As in, just the pipe with the cat-core knocked out? Are the aftermarket pipes a bigger diameter or do they just have a more open mesh in the cat?

  4. Comment author image

    JAMES TULLIS

    says:

    Thank You, I just bought a 2012 WHITE X5 WITH 57,000 MILES. The first 3000 miles were mostly 80 mph between Costa Mesa and Las Vegas before the Oakland California trip. I loved the power and the get out of my way power where I had to set a speed alarm at 92 mph to alert me of the additional power just under my foot.
    To read your honest thoughts reassured me I bought a affordable race truck…Thank You for your explanation of common items