The Subaru Impreza WRX STI gets all the attention. The rallying. The Group A homologation. The wing. The noise. Understandably so — the STI is one of the greatest performance cars ever made. But while everyone was watching the Impreza, Subaru was quietly putting essentially the same drivetrain into a larger, more comfortable, more practical car and getting almost zero credit for it. The Legacy B4 BH5 deserves to have its moment.

The BH5 Legacy B4 launched in 1998 and is the version most enthusiasts refer to when they talk about the Legacy B4. It ran until 2003. The RS/B4 variant specifically is what makes it worth discussing: a 2.0-litre EJ20TT twin-turbo boxer engine, symmetrical AWD, and a chassis tuned to be a proper driver's car rather than just a comfortable family saloon.

The EJ20TT: Sequential Turbocharged Boxer

The EJ20TT in the Legacy B4 is a sequential twin-turbo setup — a smaller primary turbo operates up to about 4,000 rpm, then a larger secondary turbo comes online for the upper rev range. This setup reduces turbo lag while maintaining top-end power delivery. The result is an engine that pulls from remarkably low rpm and then continues pulling hard all the way to the red line.

Factory output is 280 PS at 6,000 rpm — the Japanese cap that every manufacturer hit. Actual output on a healthy example is typically slightly higher, around 290-300 PS at the wheels on a stock tune. The EJ20 responds well to modifications: upgraded intercooler, exhaust, and ECU tune can push a BH5 to 350 PS without touching the internals.

The boxer layout gives the Legacy an extremely low centre of gravity compared to inline or V-configuration engines. Combined with symmetrical AWD and a well-sorted suspension, this produces a car that changes direction with a stability and planted feel that catches you off guard given its size.

Why It's Better Than You Think

The Legacy B4 is larger than an Impreza. It's more comfortable. The interior is quieter and the ride is less demanding. This made it a driver's car that could also be a daily driver without driving you insane — something the hardcore STI occasionally struggles to be on bad roads.

The B4 also has a proper boot. Four large doors. Adult-sized rear seats. All the things that make a car actually usable for more than track days and mountain roads. Subaru managed to package genuine performance car hardware inside something that's practical enough to use every day.

The RS spec adds Bilstein shock absorbers, a sports-tuned suspension, and a more direct steering setup than the base Legacy. It's not quite as aggressive as STI suspension, but it's genuinely good — the kind of suspension tune that communicates what the tyres are doing without punishing you on normal roads.

The Six-Speed Gearbox

The BH5 RS spec came with a six-speed manual gearbox — a proper close-ratio box with good feel. The ratios are spaced to keep the turbo in its power band between gear changes, which makes spirited driving feel natural and mechanical. The clutch has a good weight and clean take-up. This is a gearbox you'll enjoy using.

Automatic versions exist and are more common (being a family car, many buyers chose the auto). Avoid these unless convenience is your priority. The manual changes the driving character entirely.

Finding One

BH5 Legacy B4s are genuinely available in Japan at reasonable prices. They're not yet on the radar of most collectors, which means you can still find clean examples without paying a premium. Look for cars with full service history, working twin-turbo system (the changeover between primary and secondary turbo should be seamless at around 4,000 rpm — any hesitation suggests issues), and no boost leaks.

The EJ20 flat-four needs proper attention to cooling — head gasket issues are the Subaru EJ engine's known vulnerability. Check coolant condition carefully, look for white exhaust smoke (steam from burning coolant), and verify the temperature gauge behaves correctly. A well-maintained engine with no gasket history is worth more than a repaired one.

Import one before the world wakes up to it. The Legacy B4 BH5 is the sleeper JDM car of its generation, and sleepers like this don't stay affordable forever.