Upgraded intakes are our first mod recommendation for people just getting into modding their BMW's, but also for people looking to push crazy horsepower. An upgraded intake is the building block to further modification as it provides the engine with the additional air capacity needed for high-horsepower applications. Additionally, it's a great bang-for-the-buck mod if you're just looking for a little extra power, sound, and performance.
Upgrade options for the N20/N26 engine are slightly more limited than some other engine platforms, but there are still a number of great products on the market. We'll walk through the performance benefits of upgraded intakes, then dig into intake styling, and our favorite products on the market.
N20/N26 Upgraded Intake Performance Benefits
- 8-15whp and wtq gains (depending on the system)
- Cool intake sound on acceleration
- Improved turbo efficiency and faster turbo spool
- Better throttle response
- 40-60% increase in volumetric air flow
A lot of people will upgrade their intakes for the sound benefit alone - the extra air being sucked in creates a cool sound that is noticeable from inside the cabin, but not too loud or annoying. However, there is also a noticeable power increase from the larger volumes of air that are flowing into the engine. More air flow equates to higher air pressure in the intake plenum which results in more combustibility and more power.
Combo-ing a Tune with an Intake
The best performance results for an N20 with an intake come when you couple the intake with a flash or piggyback tune. While you can expect around the range of 5-8whp from an intake on a stock car, when you add a tune with it, you can expect closer to 12-15whp. Additionally, the intake compliments the tune and helps the tune provide larger power increases than it otherwise would.
A turbocharger works by compressing air. When you add a tune, you usually increase the boost pressure (psi) of the turbo. This means that the turbocharger needs to compress more air before it sends the air into the engine. If you don't have an upgraded intake, the turbocharger will be have to work harder to compress the same amount of air flow to significantly increased pressures. With an intake, you're now sucking more air into the turbo, which naturally increases air pressure, so now the turbocharger doesn't have to work as hard - hence the increase in turbo spool caused by an intake.
Overall, a tune is the 2nd modification step we recommend after a tune. You can rune a tune without an intake, but it puts extra strain on the turbocharger and will limit the performance benefit of the tune.
N20/N26 Intake Upgrade Options
There are primarily two types of intake systems you can buy for the N20/N26: open-air systems and box systems. Open-air systems use cone-shaped filters that sit open (if you didn't guess) in the engine bay. Most of the open air systems for the N20/N26 will have heat shields or covers that block heat from the engine block to keep intake air temps low. Box systems use a filter (either cone or square) that sits within an enclosed box - very similar to the stock intake.
The stock intake is a box system with a square filter inside of it. The box itself restricts the quantity of air that it can hold and also has a smaller filter. With that, the two ways to increase air flow are: 1) remove the air box, or increase its size, and 2) increase the size of the filter for more flow.
Generally speaking, open-air systems will flow more air than closed-box systems and provide better horsepower gains.
Here are the N20/N26 intake systems I'll cover in more depth:
- Injen open-air intake
- Injen Evolution (box intake)
- MST Performance
- aFe Momentun "Cold-Air Intake"
The Injen N20 air intake is one of the most popular on the market. It's known for being one of the louder systems, and sounds great. It uses an open-air style, but has heat shields behind it, and on-top for for heat prevention. The rear shield protects the intake from the heat on the engine block and the cover shield (pictured below) that protects it from hot air hanging around at the top of the engine bay.
Here is a picture of the top cover, which looks pretty cool in my opinion.
At ~$350 this is one of the more affordable intake options for the N20 and N26. With this system, you'll get the same increased turbo spool, throttle response, and sound as all upgraded intakes and approx. ~12whp and ~12wtq gains when coupled with a tune.
Horsepower Gains: ~12whp (10-15whp claimed)
Torque Gains: ~12wtq
Price per whp: $29.17 per 1whp
The N20/N26 Injen Evolution is a box system that features a cone-shaped filter inside of an enclosed box, with a heat shield covering the top of it. Surprisingly enough, Injen claims better horsepower gains on this closed box system compared to the one mentioned above. Dyno results claim 14whp and 15wtq on what looks to be a stock N20 without a tune.
The box and cover will make this one of the quietier systems, so if you are looking for more sound, go with the above system or the MST Performance one below. Overall, the reviews on this system are good, however, it is less popular than the above Injen system as most people want the added sound benefit.
Horsepower Gains: 14whp
Torque Gains: 15wtq
Price per whp: $27.14 per 1whp
The MST Performance intake for the N20/N26 is a similar design to the Injen open-air system. It uses a large cone filter, with a more compact heat shield housing. While the system appears to look more like a box system, it is more similar to an open-air system as the "box" is simply a heat shield wrapped around the filter and doesn't provide the air pressurization that a box system would.
MST Performance is newer to the BMW space, but their products have received great reviews so far. With dyno claims of 13whp, the system makes good power gains, comparable to other intake options mentioned here. Overall, this is a great system that has gotten great reviews so far in the N20/N26 community.
Horsepower Gains: 13whp
Torque Gains: 10-15wtq
Price per whp: $34.62 per 1whp
4. aFe Momentum Cold-Air Intake N20/N26
The aFe Momentum is a true closed-box intake for the N20 and N26, most similar to the stock intake. Like the other systems here, it uses a cone shaped filter that is enclosed within a fully-sealed box. aFe claims a 42% increase in air flow compared to the factory intake system, with 10whp and 14wtq power gains.
If you view the two links, you'll notice the system is sold with one of two filters: the Pro Dry S filter and the Pro 5R oiled filter. Most people get the dry filter with their N20/N26 as an FYI.
Horsepower Gains: 10whp
Torque Gains: 14wtq
Price per whp: $40-$50
N20/N26 Intake Conclusion
There is a lot of hooplah on the forums about intakes not adding any power on the N20 and N26 engines, and that it's just a sound mod. A lot of people say just use a K&N drop-in filter and save the $$, or keep the stock system unless you are going to upgrade your turbo.
The N20 and N26 do have really strong OEM intake systems - however, in our opinion, an upgraded intake is still worth it IF you plan on upgrading your car further with a tune and other mods. If you don't plan on adding a tune, sticking with the OEM intake system is completely fine. With that being said, a lot of people still want the added sound from the intake, so here is our thoughts on sound:
- Injen open-air: loudest
- Injen Evolution: quietier
- MST Performance: louder
- aFe Momentum: quietier
When it comes down to choosing a brand, they really all do the same thing and they are all great intakes. It really comes down to brand preference and sound preference. The injen open-air is probably the most popular on the market, but there is nothing wrong with the other systems. Also, I will note that there are other systems out there on the market, these are just some of the more popular and more afforable options.