Uncommon Performance: 1985-1989 Merkur XR4Ti

Merkur XR4Ti? Unless you grew up steeped in affordable 80s import exotica, it’s entirely possible you’ve never even heard of the low-volume turbocharged hatchback. This strangely-named fruit was at its core a rebranded version of the Ford Sierra, and found itself embroiled in an ultimately unsuccessful attempt made by Ford to introduce Americans to the best its European division had to offer.

In the Blue Oval’s heart of hearts Merkur would have one day competed against the likes of BMW and Mercedes-Benz at the lower end of the luxury performance market, but as evidenced by its very short run – a mere five model years, with the Merkur name being abandoned entirely in the last two – it was never meant to be. And yet, for thousands of believers the XR4Ti has never died, living on thanks to its uniquely tunable turbocharged drivetrain, on-the-nose 80s styling, and relatively inexpensive pricing in the decades since it was last sold new.

From The Factory

There is a lot to like about the Merkur XR4Ti right out of the box. Every model that was imported to America was outfitted with Ford’s 2.3-liter turbocharged four-cylinder engine, a unit quite similar to the one that had also found its way under the hood of the very quick Ford Mustang SVO (as well as the Ford Thunderbird Turbo coupe). They key difference between the Merkur and the Fords with which it shared its beating heart was the lack of an intercooler for the XR4Ti. Other notable changes included a host of stiffer and lighter engine parts used throughout its assembly in a bid to smooth it out and attract the premium crowd that Merkur was aimed at.

The turbo engine was a boon that tied in to Ford’s inability to import the Sierra’s naturally-aspirated Euro-spec V6 without having it be choked by EPA regs, along with the discovery that the Mustang GT’s 5.0 V8 was simply too heavy to preserve the balanced nature of the XR4Ti’s platform. As it was, close to a thousand new parts (adding nearly 250 lbs of curb weight) were needed to clear the Merkur for sale state-side, and the end result was 175 horsepower and 200 lb-ft of torque from the turbo four – excellent numbers in an era where eight-cylinder engines were having trouble filling their lungs to keep pace.


On the transmission front, the XR4Ti was offered with either a five-speed manual (Borg-Warner T9) or a rare three-speed automatic, with the latter cars seeing their boost restricted to under 10 psi to drop 30 horses from the mix and protect the gearbox’s fragile internals. The five-speed cars could be relied on for 0-60 acceleration runs in the eight second range, and unlike the Ford Mustang SVO the Merkur also benefited from a fully independent rear suspension system that made it more friendly on a track or autocross course than its pony car contemporary.

From The Aftermarket

As with almost any turbo motor, the most effective upgrades that can be made to the Merkur have to do with improving its ability to breathe – both in, and out.

“As far as of bang for the buck, we always point people towards exhaust,” say Shannon Gustafson, owner of Stinger Performance, a shop focused on the Merkur and its 2.3-liter engine. “A free-flowing three-inch setup with a straight-through muffler is typically good for 40+ horsepower versus stock.”

Gustafson explains that the next step for increasing power is to install an intercooler in the XR4Ti. “You need an intercooler so you can safely add boost to the car,” he says, “but you should stay away from a junkyard SVO or Thunderbird setup, as these are top-mounted and sit over the hottest part of the engine – the exhaust manifold. They also have no access to airflow, since the Merkur lacks a hood scoop, and there’s some flange compatibility issues with the non-intercooled turbo compressor housing. A front-mount intercooler is a much better solution.”


Shannon also insists that the Merkur XR4Ti’s factory turbo is quite capable of hanging in there as you turn up the wick. Pushing between 21 to 23 psi delivers 250-275 horsepower at the wheels, which is over a hundred more than it was putting down when it first left the showroom. Combined with a front-mount intercooler, exhaust, and a boost controller you’re looking at a very reliable bolt-on setup for the street, with enough fuel support from the stock injectors to keep the motor happy.

“Some builders also swap in the 3 1/8 inch vane airflow meter from a later Ford turbo setup in place of the 2.5 inch ‘small VAM’ design, and because the Merkur’s computer runs rich enough, it’s a safe change to make that gives you more room to grow in terms of air measurement and flow,” says Gustafson.


Moving beyond simple bolt-ons, the Merkur’s 2.3-liter is capable of supporting significantly more power for anyone who’s willing to invest in a larger turbo and aftermarket engine controllers. “The stock bottom ends can handle 400 horses to the wheels,” says Gustafson, “and once you’ve freed the car of its 30 year old electronic systems and their various quirks, it’s impressive how much can be accomplished with ported intakes, heads, and cams. The aftermarket ECUs that we offer have opened up a whole new world for these motors, and the market for both XR4Tis and SVOs is bigger today than it is when I first started tuning them back in 2000.

One thing to keep in mind when pursuing more power in the XR4Ti is that the transmission and the independent rear end aren’t intended to survive repeated drag passes at power levels surpassing what you’d achieve with bolt-ons. T5 swaps are common in big number cars, but you won’t find many Merkurs riding on a live axle because at that point, it’s cheaper and easier to go the Mustang route. Gustafson also points out that most XR4Ti owners are more into the road racing scene, where there’s really no compelling need to move past 250 wheel horsepower to have a good time. Although not a common car, there’s plenty of coilover, lowering spring, shock, and swaybar availability for the Merkur.

From Left Field

There were a few tuners back in the Merkur XR4Ti’s heyday that tackled the turbo motor and produced quicker versions (like the Rapido Group’s 190 horsepower, intercooler-equipped package), but perhaps the craziest period-correct conversion was the Scorch XR4Ti built by Ralph Todd. Although only a pair were built, the Scorch swapped in the Nissan 300ZX’s twin-turbo VG30DETT, a carbon fiber driveshaft, Corvette ZR-1 brakes, and then tuned the whole shebang to produce 550 horsepower at 20 psi.


With so much potential locked up inside the 2.3, there’s not a huge need to swap in something as out-there as what the Scorch brings to the party, but given that this is 30 year old car that doesn’t mean that folks haven’t been keen to experiment with the Merkur’s empty engine bay. There are Lexus 1UZ-FE V8-powered XR4Tis for those who want to live in acronym city, 2.0-liter EcoBoost projects, junkyard turbocharged 351s, and, as shown in the video below, even LS-powered builds.

It’s also worth noting that the XR4Ti was campaigned in the Trans-Am series after being massaged by Roush, whereupon it won a championship, as well as its class at the 24 Hours of Daytona in its last year of production, making them tempting low-buck track monster targets.


Thirsting for more about the Merkur XR4Ti and its combination of consonants and turbocharged power? The forum run by the Merkur Club of America is a great place to get started, with Merkur Tech also offering useful resource for the DIY-inclined. In addition to Stinger Performance, you can also get in touch with Merkur Midwest as well as MC2 Racing for further professional advice about modifying your XR4Ti.

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