The BMW N20 2.0L 4-cylinder is a great engine overall. They're sporty, efficient, and fairly reliable engines. A tune and simple bolt-on mods can also push the N20 beyond 300whp. Those looking to push things to the next level will need to consider an N20 turbo upgrade. However, pushing the N20 engine too far doesn't come without risk. In this article, we discuss N20 turbo upgrades along with the risks and costs that come along with more power and boost.
*Vargas Stage 1 Turbo pictured above
BMW N20 Engine Limits
We've talked about the limits of the N20 in a few other posts. Unfortunately, the N20 does not have a great reputation for strength and durability once pushing above 325-350wtq. Putting upper limits on an engine is never easy, so it's a rough estimate. Anyways, the N20 can hit those numbers on the stock turbo. The rods and pistons are known to have occasional issues above that. Point is - an upgraded turbo on the N20 can push the engine to and beyond its breaking point.
However, turbo upgrades have a few benefits to engine safety. There are also other ways to avoid damaging your BMW N20, and we'll circle back to this point in a moment. For now, let's highlight a few of the benefits of larger turbos.
N20 Upgraded Turbo Benefits
- Shift the power curve right
- Less low-end torque / slower spool
You'll notice we quoted the N20 engine limits in torque and not power. That's because torque is the measure of force and that is more directly tied to the stress the engine is under. A larger turbo can actually make less peak torque, but still have more power. This is known as shifting the power curve right. A larger turbo probably can make higher peak torque, though. It will require some tuning to keep the N20 within a safe range.
Turbo upgrades often sacrifice a little spool and low-end torque in favor of more power up top. Low-end torque is very hard on an engine. The pistons are moving slower, which subjects the cylinders to greater stress. It's also more time for the cylinder to potentially pre-detonate, which is never good news when pushing the limits. That said, most upgraded N20 turbo can still push the engine to and beyond its limit.
Reducing Risk of Engine Damage
This somewhat ties into the above. Focus on shifting the power curve right and limiting low-end torque. A lot of this comes down to tuning, which is one of the most important factors. Here is a list of a few things to do to help prevent blowing the N20 engine at higher power and boost:
- Proper supporting mods
- E85 or WMI
It's not an exhaustive list by any means. Nonetheless, a well set-up, conservative tune goes a long way in ensuring the safety of the N20. Supporting mods like cooling, downpipes, etc also help. Knock out any maintenance prior to upgrading the N20 single turbo. E85 and water-methanol injection reduce the risk of the engine knocking or pre-detonating.
Finally, data-log frequently. You want to ensure the N20 isn't leaning out, having too many major timing pulls, etc. This is all pretty basic stuff that should be done for any forced induction engine that's pushing the upper limits of the engine. Alright - with all that info out of the way - let's move onto the more exciting stuff.
**Even if everything is done right there is still risk of blowing up the N20 with turbo upgrades. Understand the risks before going down this road.
Best BMW N20 Turbo Upgrades
Below we'll dive into a few of our favorite turbo upgrades available for the BMW N20. This isn't an exhaustive list as many options exist and we don't have time to cover them all. Nonetheless, we'll list a few N20 turbo kits we believe offer a great balance of price, quality, and performance.
1) N20 Pure Turbo Upgrades (325-375whp)
Pure Turbo is well known for their work in the BMW world. They build some great turbo upgrades for most of the modern turbo BMW engines. Unfortunately, Pure never posts many technical details about their turbos. However, the stage 2 turbo for the N20 appears to be a stock frame turbo with larger compressor and turbine wheels.
Pure shows a dyno of the N20 stage 2 turbo making 382whp and 440wtq. As a stock frame turbo that may be pushing the limits a little. However, we believe the Pure N20 turbos should be good for about 325-375whp. Much above that is likely beginning to push outside the efficiency range of these turbos. Nonetheless, Pure makes solid products for a fair price. It's hard to go wrong if you're looking for an N20 turbo upgrade.
Buy Here: N20 Pure Stage 2 Turbo
2) N20 Dinan "Big Turbo" (325-350whp)
This is an interesting one. Many BMW enthusiasts are likely familiar with Dinan. Their products are typically pretty pricey in part due to warranty reasons. However, at $1300 this is actually a very reasonable option for N20 turbo upgrades. It's hard to go wrong with the Dinan brand, however their products are usually a little less performance oriented. That might be a good thing for the N20 due to the upper limits of the engine, though.
Dinan claims their N20 Big Turbo Upgrade is good for 345 horsepower. It's a stock frame turbo with a new stock turbine wheel. On the other end, the compressor wheel is upgraded to help move more air. A completely stock turbo on the N20 can support just over 300whp. As such, we suspect with the proper mods and fueling the Dinan Big Turbo will support about 325-350whp. It might not be a ton of power compared to stock, but the turbo price is right. It's also a reasonable ballpark for power without absolutely maxing the N20's limits.
Buy Here: N20 Dinan Turbo
3) N20 Vargas Stage 1 Turbo (325-350whp)
Vargas is another company well known for their BMW turbo upgrades. The price of $1,300 is pretty enticing, too. Sticking with the theme, Vargas starts with a brand new stock N20 turbocharger. It's then custom cast to accept a custom billet compressor wheel and stock turbine wheel. In essence, it's a very similar offering to the Dinan option discussed above but lacks the upgraded turbine wheel that Pure offers.
As with the Dinan N20 turbo, we suspect the Vargas Stage 1 offering will support about 325-350whp with proper mods and fuel. 350whp is exactly what Vargas claims on their website. Another solid option all around if you're looking for turbo upgrades on the N20.
Is Upgrading the N20 Turbo Worth It?
We're touching on this last since it's a very subjective question. To be clear - whether or not it's really worth it is for each person to decide individually. However, it's hard not to at least bring this up for a few reasons. Again, the N20 is really starting to push the limits even on a stock turbo. These upgrades will subject the engine to more stress and increase the risk of damage.
Also, add up all of the supporting mods, tuning, turbo cost, etc the all in cost can start getting pretty high. At that point the N54 and N55 engines (among other options) may become cheaper options if power is the end goal. Even just a tune and a small E85 mix on those engines can push into the ballpark of 350whp. Maintenance may be more expensive, but it will likely cost $3-5k+ to get the N20 to 350whp. The cost of buying the cars up-front is pretty similar.
We can see situations where an upgraded turbo N20 makes sense and is worth doing. However, info and data on N20 upgrades is pretty limited for a reason. People looking for power typically opt for the larger, more capable inline-6 engines.
BMW N20 Upgraded ST Summary
The N20 is a solid all around engine from the factory. A tune and basic bolt-ons can push the N20 to 280-300whp and 325+whp. However, that's already pushing the limits of the small 2.0L engine. Those looking for more power may consider turbo upgrades, but should understand the risks that come with it. Proper tuning, mods, fueling, and data-logging go a long way in keeping the engine safe. However, some risk is still there.
Pure, Vargas, and Dinan offer some excellent turbo upgrades for the N20. The Pure Stage 2 turbo is slightly more capable as they mod both the turbine and compressor wheel. Dinan and Vargas use stock turbine wheels with larger compressors. A little less capable, but also a bit more cost friendly. They're all great options to help boost the N20 to new heights that it simply can't reach with the stock turbo.
Are you considering an N20 turbo kit?
Drop a comment and let us know!