240SX Engine Swap

Why are so many people swapping this engine into their cars? To answer that you have to take a good look at the 240SX. Rear wheel drive, sophisticated multi-link independent rear suspension, near perfect front / rear weight balance give this car light, tossable, very impressive handling. The 240SX’s road race very competitively, often able to make up for lack of power in every turn, consistently catching up against some impressive rivals.

With plenty of aftermarket suspension support you can really get a world-class handling package put together for a reasonable amount of money. Considering that a used good condition 240SX can be found for under $5000, the entry price is way below and the performance potentials far exceed other similar performance options.

So the handling is all set, what about the power? Due to marketing decisions, the US never got to see the 180SX / 200SX / Silvia with the high-performance engine the car was designed to exploit, the SR20DET. Instead, we got the KA24 engines, SOHC in 89 and 90 and DOHC from 91 up.

SR20DET engine
SR20DET engine

The SR20DET engine came in the 180SX / 200SX / Silvia S13, S14 and S15 models. The transmission and rear differential are the same for all the models, so they are factory designed to withstand the power from the SR already. The engine bolts right in to the 240SX, so does the transmission. There are several things that need to be done custom, but not a lot. The electrical system wiring is not very difficult.

The SR20DET also responds very well to modifications. Stock boost can be safely increased to about 14 psi (really pushing it), the turbo can be upgraded, and JWT makes a custom injector / ECU / MAF upgrade. Not to mention the tons of mods available for the engine in Japan. In Japan, the Silvia is extremely popular so there is a huge market for modifications and parts.

The Nissan 240SX has many parts available for engine swaps. Motors and their body kit accessories are readily available from Japan. The Nissan Silvia and 180SX are a great source of upgrade parts for your 240SX. Some parts are available from locally available online retailers in North America.

The SR20DET is the most common motor swapped into the 240SX. It is lighter than the original engine available in North America. It offers better handling and more power, as well as having usually traveled less mileage. The other motor options have benefits and disadvantages as well. Instructions for the installation of the SR20DET are readily available through numerous online sources.

A 240SX engine swap is a great idea for replacing a higher mileage stock KA with an engine that has twice the power and less than half the mileage. You will finally put “the shoe on the other foot” and start winning against cars that are much faster. They’re in for a surprise at the next set of lights. Imagine beating the pesky LT1 camaros in your neighborhood. Won’t that make you feel good? Winning is an awesome feeling. And you will be able to keep it up with all of the Nissan 240SX engine upgrades available.