Toyota has built a ton of great engines. Enthusiasts evangelize the 4A-GE used in the AE86 Corolla and original MR2, the 1UZ V-8 found in so many trucks, and the tuner’s favorite, the Supra Turbo’s 2JZ-GTE straight-six. But one alphanumeric you don’t hear as often is 3S-GTE, despite the fact that it’s one of Toyota’s most successful racing engines. The 3S-GTE found a home in many great road cars too, and it’s one with a ton of tuning potential.
The 3S-GTE debuted in 1986 with the Celica GT-Four (called the All-Trac Turbo in North America), and later appeared in the MR2 Turbo and Japan-only versions of the Caldina wagon. It’s part of Toyota’s “S” family of engines, which were developed in the 1970s to achieve the seemingly opposed aims of building a smaller, cleaner, more-economical engine while also improving performance.
Toyota opted for an iron block and an alloy twin-cam head, and when it came to a higher-performance variant, Toyota turned to longtime partner Yamaha for assistance. The resulting 16-valve 3S-GE debuted in a Japanese-market Camry in 1984, touting 160 horsepower and 137 pound-feet of torque.
The same year the 3S-GE debuted, Toyota began development of a mid-engine rally car, the 222D, which would compete in the coming World Rally Championship Group S class, which ultimately disbanded over safety concerns during the shambolic 1986 WRC season. When global rallying switched over to Group A touring cars converted for sideways antics, Toyota decided to campaign the upcoming Celica GT-Four.
According to a history from Toyota UK, the 222D was tested with a version of the all-wheel drive drivetrain from the upcoming GT-Four. So we know Toyota had worked on a turbocharged version of the 3S-GE by the mid 1980s. At the same time, it was developing a race engine based on the 3S, the 503E. It’s unclear exactly how much the two shared, but we know that the 503E displaced 2.1 liters and was capable of over 700 hp thanks to its enormous turbocharger.
First came the Celica GT-Four road car, which entered production in 1986 with around 190 hp from its 2.0-liter, 3S-GTE. Next year, the 503E made its debut in Toyota’s 87C Group C prototype race car, where the engine made more than 600 hp. In 1988, the Celica GT-Four made its WRC debut running a series-limited 300 hp, give or take a few.
“[In the] 3S, everything’s like 25 percent bigger from the 4A-GE,” says Aaron Bunch of Texas shop ATS Racing, which specializes in the 3S-GTE. He compares the rod and bearing sizes to those of a Chevy V-8s, which is why they can handle so much power. Four-hundred fifty horsepower on stock internals isn’t difficult.
Soon after the 87C’s debut, the 503E came to America with Dan Gurney’s All American Racers, which was contracted to develop an IMSA GTP car for Toyota. AAR ran a version of the 87C’s successor, the 88C, and later debuted its own car, the HF89. The 503E powered the HF89 and later HF90 to five victories over two seasons, but in the Eagle MkIII of 1991-1993, the engine really hit its stride.
“When I first started, the power output was around 700 hp,” recalls Michael Cook, an engine builder at TRD USA in the early 1990s. “There were lots of exaggerations of the power level, some putting it at 900 or 1,000, but these are not accurate. The power level was a closely guarded secret, but at Daytona 1991, we ran about 700 and sprint races were up in the 790-800 range.”
Remarkable figures for a four-cylinder engine built more than three decades ago. This engine, combined with a brilliant chassis designed and built by AAR, proved nearly unbeatable. Motor Sport magazine said the car made around 10,000 pounds of downforce, and in IMSA, it won 21 of the 27 races it entered. It was so good, IMSA ended the GTP class at the close of the 1993 season.
Cook recalls the engines being generally reliable, but early on as power levels rose, TRD had trouble with mechanical fuel pumps, which slowed when the car was in the pits, as they were driven by the camshaft. The fuel would boil, and the mixture would go super lean. This typically caused the #3 cylinder to fail.
“We lost many race positions because of these failures, which were sometimes attributed to alternator failures in the press releases,” Cook says. “It was true that the alternator sometimes failed when it was smashed by a connecting rod exiting the block.”
A switch to Bosch electronic fuel injection remedied this issue.
While related to the 3S-GTE, the 503Es were true race engines, built by TRD in Japan and in California. Many were destroyed with a sledgehammer through the block after being raced, but some survive in MkIII chassis to this day.
The Celica GT-Four rally car made its debut in 1988, but it didn’t take its first victory until 1989, with Juha Kankkunen claiming the Australian Rally that year. In 1990, the floodgates opened, with four victories and a driver’s title for Carlos Sainz. The next year, Sainz and Toyota were runners up to Kankkunen (who switched affiliations) and Lancia, and in 1992, Sainz would once again win the title in the new ST185 Celica GT-Four. Finally, in 1993 Toyota would take both titles, having resigned Kankkunen, and in 1994, it did the same, albeit with Didier Auriol.
Toyota evolved the 3S-GTE road engine. In the ST185 GT-Four, a world-first twin-scroll turbocharger—which Toyota called “Twin-Entry”—and new intercooler helped boost output to 222 hp and 224 lb-ft. This engine was also used in the MR-2 Turbo, being Toyota’s best option for a high-performance, transverse, turbocharged four-cylinder. Another new turbocharger and intercooler for the third-generation ST205 Celica GT-Four of 1994 helped push output to around 250 hp, though we never got this engine in the US.
The ST205 is best known for its ingenious cheating turbocharger, which bypassed its restrictor plate when installed in the car. Toyota was banned when caught, and only returned to rally in 1997 with the Corolla WRC, which borrowed much of the ST205’s running gear. The Corolla WRC never achieved many victories, but it did bring Toyota a manufacturers title in the 1999 championship.
Even after the IMSA GTP program died, TRD USA still had a use for the 503E. It was used in Rod Millen’s Pikes Peak Celica, which made the fastest run up the mountain in 1994, 1996 and 1997, and was later plugged into Millen’s Tacoma, which won in 1998 and 1999.
In Japan, the engine was adapted for use in the Japanese Grand Touring Car Championship Supra, as it was much lighter than the road car’s six-cylinder 2JZ. So equipped, the Supra GT500 helped power three JGTC drivers titles and two manufacturers championships. A 3S-powered Supra even made an appearance at Le Mans in 1995, though to no great success.
So why isn’t the 3S-GTE better known today? Not many of these engines came to the US. Toyota sold vanishingly few Celica All-Trac Turbos here, and while the MR2 Turbo was a better seller, it was still a niche product. Like so many high-performance Japanese engines, Toyota didn’t bother recertifying it for 1996 OBDII emissions.
Bunch points out that Sport Compact Car magazine got serious power out of a 3S-GTE in a MR2 Turbo build series in the late 1990s, but Honda K-series engines, which are in plentiful supply, are more popular these days.
“The furthest I pushed a 3S was up to 870 wheel horsepower. Once you get up to the 900 wheel level, you’re a pioneer,” he says “You’re the only one, you don’t have anyone to ask for help. K-Series motors have people running 1500-1700 horsepower, so it’s actually going to save you money to go over to that.”
Still, the 3S-GTE and 503E are great motors, products of Japan’s Bubble economy that saw automakers making huge investments into engineering. Don’t forget that this is of the same era as the mighty 2JZ-GTE, an engine so overbuilt, it’s still used for high-horsepower builds today.
While you’ll likely always find the 3S lurking somewhere in the 2J’s shadow (despite its championship-winning pedigree), it’s remembered fondly by the true believers, deserving of its place in the pantheon of Japanese motorsports greats.
