MR2-S Honda K20 K24 Swap

Bigger, better, faster!

The 2ZZ will always be the easiest and cheapest engine swap upgrade for the MR2-S but for those who want more, especially those who want outstanding Naturally Aspirated torque and power, we bring you the Honda K swap.

What’s a K?

Do some reading on WIKIPEDIA for in-depth info. Honda’s K engines came out in the early 2000’s and set the standard for 4-cylinder performance. The two engine variations that we specifically support are:

K20A2 (200hp/142 ft-lb) / K20A (up to 217hp)
Comes from 2002-06 Acura RSX Type S (US market) and 02-06 Honda Integra Type R (overseas)

K24A2 (205hp /165 ft-lb) – MWR’s favorite for street driven cars
Comes from 2004-08 Acura TSX and some overseas performance variants of Accord and Odyssey

We will just call these two K20 and K24 from here on for the purposes of this article. There are many other Honda K engines out there. Some are fairly interchangeable, like the lower power variants from those same years. Some people even build K20/K24 hybrid engines to save money- see the Honda forums for info on that. Newer stuff like the current Type R turbo 2.0L uses a completely different generation of electronics, all different mounts, different bellhousing pattern… not at all compatible with any of our swap parts.

The Honda K series transmission is an upgrade over the Toyota C series transmission and it bolts directly to the Honda K engine of course so we use them in all of our swaps.

Swapping info:

Mounting: both engine and transmission options supported by MWR work with the MAP Mount Kit or Innovative Mount Kit.  K24 requires addition of MWR K24 Mount.

Engine Management (ECU): the stock Honda ECU has an immobilizer. Easiest and best solution is to get one with HONDATA software installed. This removes the immobilizer (making it usable) plus adds full tuning capability via laptop. Works for K20 and K24 engines. Usually engines don’t come with an O2 SENSOR and you’ll need the correct Honda type.

Wiring: You will need 2002-04 RSX CHARGING and ENGINE wire harnesses. If you are installing a K20A or K20A2 (RSX Tpye S 02-04) then your engine may come with these harnesses (and a core ECU). Any other engine and charging harness will NOT work.  You will also need this ADAPTER HARNESS which plugs right in. With this wiring combination you’ll have full engine functionality, a working OBD port and working gauges (except for charge light and coolant temp, you must add an aftermarket gauge for coolant temp).

Air Conditioning: If you have a Hondata ECU and the harnesses mentioned above then you can add the AC CONTROL MODULE and AC BRACKET for a fully functional AC system. Uses your original MR2-S AC compressor and lines for easy install. Make sure to get the right BELT.  If installing without AC, you need this BELT.

The K power steering pump must be removed and replaced with this IDLER PULLEY ASSEMBLY.

Engine: The K20 comes with a cable style throttle body, all set. The K24 comes with an electronic throttle – you must install a K20 intake manifold and throttle body or use an adapter to install a cable type Honda throttle body to your K24 manifold.

For the 02-06 RSX/Integra 6-speed transmission – use this shift ADAPTER.  Other transmissions are possible but some fabrication will be needed to make the cables work.  You’ll need a INSANE SHAFTS Intermediate Shaft or standard K-series INTERMEDIATE SHAFT. And of course you’ll need swap axles: MAP .  For either transmission you need this SLAVE CYL HOSE and, if you don’t have one, a standard Honda SLAVE CYLINDER.

Plumbing: we’re working on instructions for this. If you are installing a K20 it makes things MUCH easier if you use the K24 THERMOSTAT HOUSING . Most people find the standard MR2-S radiator adequate but for a high power build and race track use you can install any standard MR2-S upgrade radiator. This BREATHER FILTER fits the valve cover well, simplifies the air inlet construction. We will soon offer an air inlet pipe with filter. The Toyota fuel pump and regulator work fine for the Honda engine, just connect the Toyota fuel hose to the Honda fuel rail.

Exhaust: you’ll need the PPE HEADER. After that comes the PPE CAT PIPE or PPE CATLESS PIPE. The K engines need to breathe so the exhaust should be full 2.5″; PPE offers SINGLE and DUAL outlet 2.5″ muffler systems to complete the exhaust system.

Looking for clutches, flywheels, alternator, or many other handy replacement/upgrade parts you may need during the install? We’ve got IT ALL.

Are you bravely converting your SMT MR2 Spyder to manual operation at the same time? You’ll need this KIT