The Honda K20 engine has certainly made a name for itself over the years. And is often very heavily praised within the JDM community. It’s relatively cheap, extremely durable and reliable, can handle a bunch of power, and is very easily swapped into any engine department as it is quite small. Due to this, people can get a little creative without having to worry their engine will blow up, so people have started installing large superchargers to the K20, the result? An abundance in power!!

Honda K20 Engine

The K20 is part of Honda’s K-series and is made up of a line of four-cylinder, four-stroke engines. Like the B-series engine, the K-series also came with the famous Variable Valve Timing & Lift Electronic Control (VTEC). The power of the K-series varies between 150-316hp depending on engine specification and year of manufacturing. The typical K20A2 engine available in the EP3 Honda Civic Type R (2001-2006) came with 200hp in stock form.

The K20 has been in production for a long time. The first K-series launched for the Japanese Domestic Markets in 2001 and is still in production to date. And although the newer engines have their naturally aspirated life behind them, the general idea of the K20 remains. It’s reliable, cheap, and can make some good power without having to lose your wallet.  

But this list will not focus on the new K20, this list will only include the old-school naturally aspirated K20, except these particular ones have some superchargers attached to them. Enjoy!

Supercharged K20A Swapped Lotus Exige

This Lotus is a special little blue gem, not only is it regularly used for track driving, but it also has a supercharged K20A for an engine. The 1.8L supercharged I-4 2ZZ-GE engine the Exige comes with from the factory is no slouch, in fact, it is really good. It would have to take an extremely good engine in order for someone to even deal with an engine swap, to begin with, such as the K20A!

This Exige redline at 9,000 RPM and has about 320 hp at its expense, and considering this particular car weighs less than 900 kg (1,980 lbs.) you can imagine this Lotus certainly shreds some lap times.

In order to make this power, the K20A has forged internals, upgraded injectors, and most important of all, an Eaton M62 supercharger. And to put the power down has a 5-speed sequential transmission (Quaife QKE8J).

Take a listen to this fabulous supercharged K20 engine!

Supercharged K20 Honda EG Hatch

This must be one of the most tastefully done Honda EG hatches in the U.S. Everything about this build just seems right, nothing is really overdone, it is just kind of…perfect.

Most K20 swapped Civic tend to be a little too fast for themselves. Many tend to remove the majority of the interior while at the same time boosting power to 400 hp+. The result is a lot of wheelspin, all the time.

This build has gone the supercharger route, as it seems like a more logical option as the supercharger more or less “enhances” the K20 whereas a turbocharger completely changes the way the car drives.

The K20A2 swapped into this Civic utilizes a CTE supercharger which together produces about 300 bhp at 8,600 RPM.

The beauty of this build is that it keeps a full interior, it has electric windows, A/C, and all the comfort accessories you could really want. So, although this small little hatch has over 300 hp there is almost no wheel spin at all. And combined with the comfort features you’ve got yourself a winner.

To add to the experience, the previous owner swapped the old transmission for a 6-speed from an RSX Type-S.

A funny feature is that the owner re-wired the check engine light, so instead of showing you when something is wrong with the engine, it lits up when it’s time to change gear!

450HP Supercharged EP3 Civic Type R

The owner of this EP3 has owned various different Type R’s throughout the years, including a turbocharged EP3 with over 500 bhp+. And although that may be fun for a while, it is not nearly as usable as with a supercharger as the owner found out.

With a turbocharged engine, you basically have zero power until a certain RPM when all power comes in at once, resulting in burnt rubber. A supercharger however has a more linear powerband, so although you have similar power you’ll not experience as much wheel spin. And that is how this lad drives around in an FWD 450 hp EP3.

Attached to the K20A2 is a Rotrex Supercharger kit, that comes with all surrounding necessities to make the supercharger work at full capacity. Along with the kit comes 1,000 cc injectors, a radiator, a boost pipe as well as a map sensor. All internals are still stock and power is achieved at 8,600 RPM, which is a little more than the factory 8,250 RPM red line.

The owner must have some really large jewels considering driving a 450hp FWD EP3 on small backroads in the countryside of Britain doesn’t sound all too safe. With all the rain they get in Britain, I can’t get the picture out of my mind of someone understeering into a field or even worse, oncoming traffic. But hopefully, they take it carefully.

420HP Rotrex Supercharged Civic Coupé

This build certainly stands out there. The first thing you are greeted by is the sheer amount of sound coming out of this K20 engine. And as it passes you, you’ll notice the ridiculous large spoiler in the rear and widened wheel arches. And if you get even closer, you’ll notice the stripped interior, racing bucket seats, as well as the full roll-cage installed. Goes without saying that this is a race car. And although it is road-registered it is only for tax reasons as it barely gets driven outside the track.

The British owner of this magnificence actually does real racing in it. And before they supercharged it was actually very successful, placing 1^st in 2019. As they added a Rotrex supercharger to the mix, power increased to 420 hp, and thus they had to join a new racing Group, unfortunately not as successful this time placing 5^th at best.

But during the right conditions, this car is incredibly fast. Even though it weighs less than 1,100 kg (2,425 lbs.) and has over 400 hp, if the conditions are right (dry) a pair of semi-slicks will totally diminish any wheel spin.

It’s not every day you see a purpose-built race Accord with a supercharged K20A2 swap.

Supercharged K20 Swapped Mazda RX-8

This one is unique in many ways. First of all, it is an RX-8 powered by a 1.3L rotary Wankel engine. Secondly, the K20 is not the ordinary K20A, or K20A2. It is a more modern one the K20Z4 from the third generation Honda Civic Type R (FN2) and makes stock 200hp. But with an Eaton TVSD1320 supercharger, it almost doubles the power to about 360 hp. A nice boost considering the predecessor (RX-7) had 280hp compared to the stock RX-8 190-240hp.

There is always the debate on whether swapping out the Wankel engine from a rotary-powered car is the right thing to do or not. You could argue the RX-7 13B-REW engine shouldn’t be swapped despite its flaws since it is so unique and actually makes good power. But in the case of the RX-8 Wankel RENESIS engine, there is nothing really that makes it good. It no longer has a turbo, it is very unreliable, and doesn’t sound near as good as the 13B-REW Wankel. We’d say swapping out the ole’ RENESIS rotary engine is justified.

And here we have a live example that this swap was indeed a good choice. This RX-8 all of a sudden got way more reliable, it got a well-needed power boost, the sound stayed the same, if not improved upon, and you’ll likely own one of the most unique K20 swapped cars in the world.

Perhaps you’re interested in knowing more about why the Mazda RX-8 receives a lot of backlashes from the car community? Then you can read more here.