How Much BMW N20 Horsepower Have?. Because the preliminary release of the N54 in 2007, BMW has earned a reputation for developing a line-up of turbocharged engines that can significant power gains with a tune and standard bolt-ons. The N20 was BMW’s very first turbocharged, direct-injected 4-cylinder engine. From the factory the greatest version of the N20, found in 28i versions, is ranked at 241hp and 258tq. Nevertheless, real life dyno testing recommends those numbers are somewhat underrated with the engine producing similar numbers to the wheels.
Depending on the presumed drive-train loss, this would put the N20 in the ballpark of 275hp and 290tq at the crank. A stout performance for a stock 4-cylinder, nevertheless, as we understand with almost any turbocharged engine, there is a great deal of untapped power that some basic mods can let loose. The concern is– can the stock elements manage the newfound power?
A Look Into the BMW N20
There seems to be a fair bit of details drifting around online forums that the BMW N20 is a reasonably weak motor. For some factor, it is challenging to discover any solid evidence the N20 is really as weak as some suggest, however that is not to state the engine is perfect. It has been plagued with a major issue involving the timing chain, which in some cases may cause complete engine failure. BMW upgraded the timing chain in 2015, which seems to have solved the issue for the most part. We will compose a more thorough post regarding the timing chain issues in the future, but for now let’s analyze the more exciting elements of the N20.
As specified, the engine is underrated from the factory and currently supplies reputable performance for a fuel-efficient 2.0 L engine. Nevertheless, for some enthusiasts, a little additional power can go a long way. Like other turbocharged BMW engines, the aftermarket industry is littered with tunes and basic bolt-on modifications.
Common mods include tunes, air consumption (CAI), catless downpipes (DP), and upgraded front mount intercoolers (FMIC). Normally, when all mods are integrated the engine might be referred to as full bolt-on (FBO). An FBO N20 engine with a little E85 mixture is capable of producing upwards of 350hp and torque. The question stays– can the N20 actually manage that much power?
As a disclaimer, it is important to note that putting a particular number on the ceilings of the stock internals and block is tough. The N20, as with any engine, may can producing greater numbers than the engine can endure in the long-run during “glory runs” on the dyno. Additionally, every N20 is different. Some might be able to produce power and torque considerably above stock levels without issues, while other engines may let go rather. With that being said, lets dive into the normally accepted ceilings of the N20.
N20 Tuning Prospective
The safe upper limits of the N20 seem somewhere in the lower-mid 300whp and wheel torque variety. This is roughly where you will wind up with full bolt-ons and some E85 in the N20, and the basic consensus is few owners are pressing their cars beyond this limit without updated rods at the least. You may be able to press the car a bit harder on the stock engine, but here are a few things to think about:
- Limit increase from stock turbos to 22psi
- Usage data logging to your benefit– watch for lean conditions
- Oil starvation under difficult braking or cornering
On a stock turbo N20 it is highly recommended to keep boost in the lower 20’s with 22psi being towards the greater end of the safety margin. Additionally, the N20 is understood to have concerns with running a bit too lean. When pressing the engine towards it’s limitations as lean conditions are more likely to cause engine knocks, this is worrying. Last but not least, difficult cornering and braking may trigger the N20 to go through a period of oil starvation. Certainly, on a stock motor oil hunger is still a terrible thing, however, increased power may lead to more substantial issues due to oil hunger.
The Importance of Having the Right Tune
I think some consider the N20 a weak motor, because it is more finicky than the 6-cylinder N54 and N55 engines. There are lots of N54/N55 owners and tuners who have no idea what they’re doing. They toss a couple of mods on the car, show up the boost, discard some E85 in the tank, and let it rip. The engines hold up extremely well on stock turbos as they are merely not making enough power or torque to do considerable damage without major abuse. In my viewpoint, the N20 is a reasonably capable engine from the factory and carries out well for a small 4-cylinder, however, they do require a bit more attention and understanding than their equivalents.
It is extremely crucial to guarantee you are running the best tune on your N20. You can not simply toss on some bolt-ons, E85, and crank up the tune to be as aggressive as possible. Guarantee you have the ideal supporting and cooling mods, and your tune is appropriately representing the mods you are running. For example, running an updated FMIC will assist in keeping IAT’s to a minimum, consequently minimizing the change of engine knock. In addition, upgraded sustaining elements for heavy E85 mixtures will assist the fuel circulation and reduce the likelihood of the engine running too lean. Simply put, keep the tune modest and do not press things too far. The additional 10hp from an aggressive tune is not worth the significantly increased threat of blowing the motor.
General Impressions
The N20 has actually earned a reputation for being a weak BMW engine, a track record that I think is incorrectly necessitated. I am not stating it is as capable as the N54, N55, B48, S55, etc but is that what anyone would expect from the engine? It is a 4-cylinder 2 liter engine that was created with entry level BMW designs, not a 6-cylinder engine created for mid-range or higher end models. If the N20 could really deal with 500whp without breaking a sweat why would any lover get excited about the 425hp M3 or 300hp N55?
Related: DIY Electric Water Pump Replacement for BMW N54/N55 E-Series
The N20 does exactly what it was designed to do, and after that some. A tune and easy bolt-ons can propel the engine into 300+hp and torque territory; reputable performance which remains pleasurable and fuel-efficient to day-to-day drive with sufficient power on tap to have some excellent fun when called upon. Nevertheless, the N20 does have its limitations which might be a concern when seeking to press things too hard.
Equip your N20 with full bolt-ons and the appropriate supporting mods and a conservative tune. Do this and you will likely have a wonderful experience driving an engine that is powerful, dependable, responsive, fuel-efficient, and an all-around satisfying driving experience. Deal with the N20 like its BMW’s twin turbo S55 engine discovered in the M3/M4, then you may sign up with the crowd of owners grumbling the N20 is too weak.
