Anyone who enjoys watching "Monty Python's Flying Circus" on television certainly understands British humor. It can be dry and subtle at times, or outright outlandish. (The Ministry …
From Whence They Came
Back in the early 1980s, with Ford's European darling, the Cortina, coming to the end of its long and prolific production run, Ford needed a car to fill the void that it would leave behind. The Cortina was a mid-sized car with rather boxy proportions and poor aerodynamic properties. With the fuel crisis of the late '70s still fresh on everyone's mind, Ford's designers decided that a more aerodynamic car would have to be designed to help curb the fuel appetite.
In September of 1981, Ford of Europe unveiled the Probe III concept. The Probe III looked more like a futuristic car from a movie set than the seeds of a production car, as it was bedecked with rear wheel skirts, aero discs over the wheels, molded bumpers and a radical-looking biplane rear wing. Still, all of these components were in response to Ford's newly adopted aerodynamic mantra, and the concept car turned in an impressive 0.22 drag coefficient. The production version of this new car would be called the Sierra.
The Sierra came equipped with a four-wheel independent suspension, using MacPherson struts up front and variable-rate coil springs mounted on trailing arms at the rear. Ford's intention was for the car to fill as many sub-segments of the mid-size market as possible, so the Sierra was to come in many different body and drivetrain layouts, including four doors, three-door hatchbacks, four-speeds, five-speeds, automatics, V6s and V8s (South Africa only). The top-of-the-line Sierra was the XR4i model.
Robert "Bob" Lutz, Ford of Europe's chairman at the time, chose the three-door hatchback version of the Sierra line as the basis on which to build a special XR sport model. Its three-door shell was further revised to include four pillars instead of the usual two. The car came equipped with the 2.8-liter, 60-degree Y6 engine of Ford Capri fame, while the suspension was tuned using a 26mm front and a 10mm rear anti-roll bar. Gas-pressurized shocks were also employed at all four corners.
Most noticeably, the XR incorporated the radical biplane rear spoiler from the Probe III show car, used upon the insistence of Bob Lutz and despite the criticism of the automotive press. This change in styling would set it apart from the more pedestrian Sierras–as well as all other cars of its day.
Ford of Europe had already had great success in selling its European cars stateside–most notably the 1970-'77 Mercury Capri and the 1978-' 80 Ford Fiesta–so Ford brass determined they had an untapped market segment for the likes of the XR sports sedan. U.S. buyers were already flocking to the Mercedes 190, BMW 3 Series, Saabs, and Audis, so it was decided that the XR sedan would compete head-to-head with these cars on both price and performance.
As they were preparing for the Sierra's entrance to the U.S. market, Ford learned that Oldsmobile held the North American rights to the name Sierra with their Cutlass Cierra, so a new name was needed.
There were bigger problems, however. Once the 2.8-liter V6 was strangled with U.S. emissions equipment, the XR was simply not powerful enough to be a successful competitor. Ford looked to its corporate parts bin for a replacement.
Fortunately, Ford of Detroit had an excellent 2.3-liter, turbocharged, four-cylinder engine that was cuITently being used in the Mustang SYO. The Lima unit, as the facto1y called it, was a perfect choice for the U.S.-bound XR, since it was designed with U.S. emissions regulations in mind. After some small modifications, such as dropping the intercooler, the engine was slated for XR use. The engine would be manufactured in Taubate, Brazil, then shipped to the Karmann factory in West Germany where the U.S.-bound XRs were being assembled.
All that remained to be determined was a name for the car. Ford was going to market the XR through select Lincolo-Mercury Dealers–an approach that had worked well with the Capri–so Bob Lutz coined the name Merkur (pronounced "Mare-coor"). Since the car was being built in Germany, why not give the car a German name? (Merkur means Mercury in German.) The Sierra XR4i would become the Merkur XR4Ti, with the 'T" being added to represent the turbocharged engine.
When the Merkur XR4Ti arrived on U.S. shores in the fall of 1984, the automotive press received the new car very well. The test drivers loved the power and speed of the Merkur, which soundly outperformed its competition in straight-line performance with 0-60 times in the mid-seven-second range and a top speed of close to 130 mph. It was the fastest Ford on the market, as well as the most aerodynamic with a 0.32 drag coefficient. The car was well balanced, too, with a 53-percent front and 47-percent rear weight distribution.
The only criticisms were its tendency to lean in the corners, the unrefined engine, lackluster brakes, and of course, its radical styling. Most writers either loved it or hated it; there was no middle ground. The soft handling was blamed on the manufacturer, which was accused of once again failing to bring over a car from Europe unspoiled. The spring rates were indeed altered from the Euro specs, and there was the added weight imposed by the U.S. safety requirements (five-mph bumpers. strengthened door beams, and so on).
The engine had already received quite a bit of attention to reduce its harshness. The 2.3-liter engine, like all inline fours, is inherently out of balance. Since the engine couldn't be redesigned on the inside, engineers focused on the external components. They learned that the ancillary components were a major source of vibration, so each one was evaluated and harmonically measured so that new components or mounting brackets could be designed to reduce vibration. Engineers also developed hydraulic engine mounts that would absorb any remaining vibration. Ford obviously thought they got it right but the press thought otherwise.
Nonetheless, the engine featured 175 horsepower when mated to a T9 five-speed transmission. The automatic cars were detuned to 145 horsepower, because the C3 automatic. which usually spent its life under the floor pans of sedate four-cylinder Fairmonts and Granadas, was not strong enough to handle the 195 ft.fibs. of torque.
All Merkurs came fully equipped with air conditioning, AM/FM stereo cassette, and full instrumentation, which included a 7000-rprn tach and turbo boost gauge. The speedometer only went up to 85 mph–the numbers were missing past that point–although in late 1988 the speedometer was changed and finally went all the way to 150 mph. Service lights were present for the rest of the vital signs.
Four-wheel-disc brakes, which were very popular with European sports sedans, were not to be found o the Merkur. Instead, it came equipped with 10.2-inch disc brakes up front and 10-inch drum brakes at the rear. This setup hurt the Merkur in side-by-side braking tests with its European rivals. Another problem stemmed from the 14-inch wheels shod with narrow Pirelli P6 tires. They were marginal at best. This problem was addressed in 1987, when the Merkur was switched to 15-inch rubber.
Options on the Merkur included a moonroof, leather seats, heated seats (only available in northern states and Canada), power windows and door locks (standard in late 1988), and aforementioned automatic transmission. In late 1988, cruise control was added as an option. The car was priced at around $17,000, which was expensive as far as Fords go, but a bargain compared to its main rivals. Unfortunately, the estimated sales forecast of 20,000 units near was never met.
When the smoke from all the hype cleared at the end of 1985, Lincoln-Mercury was left stunned. Where were the buyers? The targeted buyrer was an affluent thirtysomething male–not the typical person who would walk through the door of a Lincoln-Mercury dealership. The salesmen usually knew less about the XR4Ti than the customers wanting to look at one, and the car looked entirely out of place sitting next to a Lincoln Town Car. (One can only imagine how the Town Car customers felt looking at the XR4Ti, with its wings and all. "Please don't do that to my Town Car," was probably their thought.)
The trend was a little better in 1986, with more XR4Tis leaving the showroom floor. However, sales were still below the forecasts, and the BMW sedans and Mercedes 190 were outselling the XR4Ti by the tens of thousands.
Finally, in late 1987, some improvements were made. Along with me larger wheels, the gray plastic body cladding and bumpers became available in body colors for black and white cars only. The new look was impressive, but the hemorrhaging was unabated.
For 1988, the XR4Ti lost its biplane spoiler to a more conservative single unit; consumer surveys had indicated that the biplane spoiler was a little too obnoxious. Bob Lutz, the so-called Father of the Merkur, would have to lose this battle. More subdued colors also became available along with conservative BBS-style lattice wheels that Ford introduced midway through the 1988 model year.
1989 was the last model year for the XR4Ti. It seemed that all the styling changes had failed to improve sale–-America as a whole didn't know what to think of the car.
Another Merkur, the Scorpio, which was based on the European Granada, was introduced in 1988 to compliment the XR4Ti. It was a more conservative four-door car with a 2.9-liter Cologne V6, but it, too, failed to sell in the projected numbers. For 1990, the entire Merkur line was dropped.
Win on Sunday, Sell on Monday?
Among the masses in the U.S., the most popular forms of motor racing are probably NASCAR stock cars and IRL/Champ open-wheel cars. With NASCAR in particular, the established relationship between winning races on Sunday and selling those cars on Monday has long been a cornerstone of the American racing scene. It's unfortunate that this philosophy didn't carry over for the XR4Ti, which posted a number of road racing wins to its credit.
In 1985, the hotly contested Group A RAC British Saloon Car Championship was won by Andy Rouse's team in their U.S.-market XR4Ti. Through special homologation papers presented by Ford's competition department, the car was referred to jointly as a Merkur and Sierra; therefore, the U.S. car could compete on English soil.
The car was essentially a U.S. home-market car specially fitted with a large intercooler, Getrag five-speed gearbox, four-wheel disc brakes, 16-inch BBS wheels, new springs, limited-slip differential, and modified turbo boost settings. Rouse estimated the car generated 300 horsepower, all from the 2.3-liter engine available to U.S. shoppers.
In 1986, Jack Roush Racing entered three specially-prepared XR4Tis in the SCCA's Trans-Am road racing series. These cars employed the same basic design layout as the XR4Ti, with rear-wheel drive and a 2.5-liter, four-cylinder turbo engine, but they rode on a pure-race-car, tube-frame chassis. However, the cars did maintain the sleek-looking styling of the XR4Ti. This combination propelled Roush's team to the Trans-Am championship title in 1986 and 1987.
In 1988, Roush switched efforts to the IMSA GTO series and continued winning championships with the XR until 1989, when the team replaced the Merkur with the Cougar.
Buying a Merkur XR4Ti
Locating a XR4Ti in your local paper is akin to finding a four-leaf clover in your yard; it happens, but you need to look closely. Fortunately we are living in the information age, with the Internet giving us many more options; a quick look at the online classifieds will yield more than a dozen cars nationwide. XR4Tis are priced from $500 for a rough one to $4000 for a mint, low-mileage '89. Most cars are priced around $1500 to $2000, and they offer tremendous value for the money.
If you don't maintain and repair cars yourself, you will have to learn how. You will be unlikely to find a mechanic that fully understands these cars, and Ford has all but abandoned them. Some of the parts you need are also no longer available from Ford, so you must rely on the small cottage industry that supports these cars. The Internet will be invaluable to you as an owner, as the chances· are good that someone out there has already addressed the issues you encounter. There are many excellent Web sites and support groups just waiting for new owners.
The XR4Ti is available in model years 1985 to 1989, with roughly 42,000 units produced total. You have your choice of five-speed transmissions or three-speed automatics, and the cars are classified into three distinct groups: The first group is the early cars of 1985 and 1986; the second is the 1987 cars; and the third is the 1988 and 1989 models.
The Early Cars
The 1985 and 1986 XRs are easily recognized by their biplane spoiler, small 14-inch rotary-phone-dial wheels, and gray lower body cladding. An '86 can be further distinguished by its third, high-mounted brake light.
The early cars are prone to a number of maladies unique only to them. The early cast exhaust manifold tends to develop stress cracks, but they can be welded back up. Still, you are better off locating a manifold from a later car, as it is reputed that the later manifold also flows a Iittle better.
In the same area of the exhaust, the catalytic converter on the early cars was subject to a factory recall. Chances are that any XR out there for sale has had the problem fixed, but it still makes sense to check this out by calling the dealer.
The top of the dashboard will crack. This is to be expected on an early car. A new dash pad can be fitted to hide the crack, or you can replace the dash with one from a later car.
The early cars also have retractable radio antennas mounted in the left rear fender, and if they're not regularly cleaned, these can fail to operate. These cars were also subject to more electrical gremlins than the later cars. One troublesome part was the oil level sensor on the dipstick giving a false low-oil reading.
Generally, the gremlins boil down to a bad relay or corroded terminal connections that can be cleaned up with some fine emery cloth and WD-40.
The '87 Models
1987 was a transitional year for the XR4Ti. The car still carried the biplane spoiler, but it signaled the beginning of Ford's XR tone-down. New 15-inch wheels were fitted that featured eight spokes–four spokes resting over the top of the other four. (People sometimes call these the "pie-spoke" or "spatula" wheels.) The early '87 cars still used the same retractable antenna found on the 1985 and 1986 cars.
While the late 1987 cars incorporated some-what improved electronics, they still had their share of faulty switches and relays. For the most part, however, these and later cars have better electronic reliability than the earliest ones. The other major change involved incorporating the radio antenna into the rear window glass defrost grid.
Also unique to these cars was the available monochromalic paint scheme for white and black cars. This option incorporates body-colored side cladding that arguably improves the appearance. A new dashboard was introduced which was less likely to crack, while the large speaker grill on top of the dash, which seemed to be the origin of the cracks on the early cars, was removed. The interior cloth material was also upgraded to a higher quality fabric. Also, the earlier troublesome Ford rack-and-pinion steering was replaced with a new aluminum ZF-made rack.
The Later Cars
Purists may argue that these are not true Merkur XR4Tis–a real Merkur must have the biplane spoiler. Their single rear spoiler and more sedate appearance identify the 1988 and 1989 cars, while new colors were introduced along with brown side cladding for gold and bronze cars. Red was added to the short list of monochromatic colors.
Early 1988 models rode on the 15-inch "spatula" wheels, which were replaced midway through the year by 15-inch, BBS-style lattice rims. Different interior colors were also added–Raven Black and Spice Brown–with matching dash colors. These dashes fit the earlier cars, so if you are boneyard shopping for a new dash, they'll work. The speedometer was also uprated to read 150 mph instead of 85 mph.
To mount the new, single spoiler, Ford redesigned the rear hatch and widened the window glass. This is important to know because if you purchase a later car and try to install a biplane spoiler, it will rest partially on the rear glass. The better approach would be to locate an early rear hatch with the biplane spoiler already fitted. This, however, presents another small problem that needs to be addressed: The radio antenna for the later cars was the rear-window defrost grid. In order for the antenna to work on the older hatch, you will need to install the electronic isolator box into the hatch for the antenna grid.
Another later car malady is the cable that runs out of the headliner to the antenna connection on the hatch. It tends to break after repeated openings and closings of the hatch.
All Cars
XR4Tis are not prone to rust, but there are a few areas that can cause problems that mostly result from poor maintenance. For example, the drain holes on the bottom lip of the rear hatch can get clogged, causing the hatch to rust. Keep the holes clean.
Also, rust can form at the bottom of the doors, thanks to dirt that gets trapped behind the plastic cladding. Keeping the door drain holes clean and checking for loose cladding will help avoid the problem. The rivets that hold the cladding on can also break, providing an ingress point for dirt and salt. New rivets are available. (The rivets are located behind the colored strip at the top of the cladding.)
Interiors tend to fall apart, as leather seats will split, and headliners will fall down. Repairs such as these can be carried out by a competent owner or upholstery shop. The rear taillight gaskets also fail and allow water to seep into the spare tire well. This causes the taillight terminals to corrode, which will introduce more problems. Replace these gaskets at the first sign of a leak.
The headlight lenses, which are made of plastic, tend to get cloudy with age, but they can be cleaned up with a good plastic polish. Note that the XR4Ti lights are not that bright to begin with. A better solution, but not a perfect swap, is to install the European-style headlights. These will bring the lighting up to modern standards.
The 2.3-liter engine is a very robust powerplant, even when it is turbocharged. Regular oil changes and maintenance will go a long way toward longevity, and the urban legend about turbo engines needing a new turbo at 60,000 miles is untrue.
The T3 turbo unit is durable, provided the owner doesn't run the car hard up until the point when the engine is turned off. This activity will shorten the life of the unit considerably, as the oil isn't allowed to circulate and cool down the engine.
Another area to keep an eye on is the timing belt, which should be replaced every 50,000 miles. There's no damage if you don't replace it (non-interference engine), but you will need a tow truck to get home if one should snap.
Every model year XR4Ti is also susceptible to radiator problems, as the end caps are made of plastic that tends to leak. They can be repaired with some gasket sealer but they will probably still weep occasionally. (The coolant level will need to be monitored religiously.) New all-metal radiators are available for around $400, and note that the radiator for the automatics is different from the five-speed's. Also take note that the 1989 cars used a radiator that is unique to that model year which cannot be replaced with one from an earlier car.
All XRs can suffer from hydraulic engine mount failure. As mentioned previously, the mounts are there to dampen engine vibration, and once they fail, you will begin to feel strong engine vibrations-with everything buzzing in the cabin. If that is the case, look underneath the engine at the oil pan. If it is resting on the steering rack or the engine appears tilted, you have bad engine mounts. Replace the transmission mount while you are at it.
Another very common source of vibration is the RotoFlex (Guibo) coupling. This donutshaped piece of rubber is part of the driveshaft assembly, and over time, it will crack and start to lose bits of rubber. If you experience a strong vibration as you take off, which gets worse as you go faster, you probably need a new donut.
Ford will try to sell you an entire new driveshaft for this repair. Don't do it. The donuts are available from other sources for about $50. In fact, some mid-to-late '80s BMW 5 Series sedans use a similar piece. (Check the BMW piece against the Merkur one to make sure the dimensions are similar.) While you're working around the driveshaft, check its center support bearing. If there is movement greater than 3/s inch, you will need a new center bearing.
The original-style camshaft cover gasket fails regularly, sending oil down the block, which is a big fire hazard around a hot turbo. Replace the gasket with a new neoprene gasket that is designed for a 1992- '93 Ford Ranger pickup. This improved gasket has steel shim-limiting washers around the mounting holes, which keep the bolts from being over tightened.
The fuel injectors are also prone to leakage around the sealing o-rings and plastic fuel injector body. This is also a good source for a fire. (Yes, XR4Tis are prone to burning up if not maintained–keep a fire extinguisher on board.)
The high heat of a turbocharged engine attacks anything made of rubber or plastic under the hood, so check all vacuum lines and fuel lines and replace these parts periodically. Even the battery will suffer from the heat.
If the car seems to be idling erratically, first check the condition of the ignition system (OEM components are recommended) and vacuum lines, and then check the throttle position sensor. Over time, they require adjustment using a voltmeter. You should also clean the throttle body and idle speed controller with carb cleaner.
Another electrical component that can fail unexpectedly is the ignition module-the engine will die and not restart. Sometimes, if you allow the engine to cool down, you will be able to restart the car. The prudent XR owner will always carry a spare module and the special ignition wrench needed to install it. Always use a Motorcraft replacement part.
The coolant temperature sender (located on the bottom underside of the intake manifold) also can fail. Ford offers a new part, commonly called the "purple-ring sender." If the temperature seems too low, chances are you have a bad sender or perhaps a clog by the T-fitting near the sender.
If the steering wheel twitches or shake slightly as you drive down the road, chances are good that the control-aim bushings need renewing. Replacing these will tighten up a loose front end considerably. Don't blame warped rotors on the control-arm bushings, however, as the same type of steering wheel movement can be felt under braking if the rntors are warped.
Making Them Faster
One of the great things about a turbocharged car is the incredible horsepower potential that is available, bolt-on, for reasonable costs. To get the same performance from an naturally-aspirated engine would require an extensive engine teardown and reduced drivability at anything other than full-throttle operation. A turbo car is like Jekyll and Hyde, with sedate characteristics off boost and ferocious tenacity on boost. How fast you want to go is related to how much boost you can safely feed the engine.
One of the first things you should do is replace the stock air filter. Using a good aftermarket filter, such as a K&N, will help the engine pull in more air. Another approach would be to use a cone-style filter instead of the standalone housing. In doing this, you will want to build an open housing that shields the air intake from the turbo's heat.
The later stock exhaust manifold is pretty good, although stainless steel tubular headers are better but expensive. Your goal is to keep the exhaust gas velocity high on its way to the turbo housing. This will make the turbine spin faster, thus creating more available boost. Installing a three-inch downpipe to the converter will also allow the turbo to spool up faster because it's not struggling with exhaust backpressure.
On the same theme, installing three-inch pipe all the way out the back through a straight-through muffler will also improve the turbo's performance. The bigger the pipe, the better. This is just the opposite of an atmospheric engine, which requires some backpressure to improve exhaust scavenging.
Everyone knows that getting a lot of power from a naturally-aspirated engine requires a healthy bit of lift and duration of the cam profile, which creates a terribly lumpy idle. It may sound cool when you hear a big V8 lumping along at a stoplight, but around-town driving is terrible.
In contrast, the turbo engine hates valve overlap. A reasonably-mild cam is all the engine needs to create power; installing a race cam into your turbo engine kills its ability to create boost until much higher engine speeds are reached.
There are, however, some good aftermarket cams out there if you do some shopping. Modem Performance a nice roller cam for the 2.3-liter engine, although a cheaper option exist and is easily found at a junkyard: the roller cam from an early-'90s Ford Ranger pickup. It's marginally better than the stock five-speed XR cam, although the main benefit is the replacement of the XR's hydraulic cam with a smoother roller setup.
As mentioned previously, the 2.3-liter engine is not a terribly refined piece. The engine and all the ancillary components tend to make some clanking noises and vibration, which can fool the knock sensor into thinking the engine is suffering detonation. The computer will retard the timing and kill power.
The solution is simple: pull the wire off the knock sensor. You will need to listen for detonation in the future, and should back off the gas and timing-just as you did before the advent of computer-controlled engines–if any bad noises are heard.
If you are a sophisticated mechanic, you can install a knock-sensing computer made for the Saab 9000 Turbo. The Saab APC computer is designed for knock sensing on a turbocharged engine, so instead of retarding the timing, it will bleed off some boost, using its own boost-control solenoid, until the knocking stops.
When the turbo compresses air, the process creates heat. A hot intake charge will not produce a lot of power because the air charge will be less dense. You want to cool the charge, before you introduce it to the engine, by using an intercooler.
An intercooler is essentially a radiator for the compressed air; unfortunately, the XR did not come intercooled from the factory. However, there is evidence on the 1989 cars that Ford was going to add an intercooler, because they moved the radiator overflow from the passenger's side of the engine compartment to the driver's side.
A popular swap is installing a Turbo Thunderbird/Mustang SVO-style intercooler. The only problem with this swap is that there is no source of fresh, cool air to pass through the intercooler; you will notice the SYO has a hood scoop directly feeding the intercooler, but the Merkur has none. However, aftermarket suppliers have designed intercoolers specifically for the XR that don't require cutting holes in the hood of your car.
The key to a good intercooler is, obviously, to cool the charge, but it must also keep the turbo boost pressure drop to a minimum. An inefficient intercooler will rob as much power as you hoped it would generate.
The wastegate's job is to vent off exhaust gases so the turbine will not spin as fast, thus reducing boost. On the XR, the boost control solenoid (BCS), which is governed by Ford's EEC-IV computer, signals the wastegate actuator to hold maximum boost to 10 psi when rpm is below 4200. Above 4200, boost is allowed to climb to 15-plus psi. (Note that this only applies to five-speed cars; the boost on cars with an automatic transmission never rises past 10 psi).
An easy way to gain power at lower engine speeds is to remove the vacuum lines going to the BCS and connect them together, effectively bypassing the solenoid altogether. This can be dangerous, however, because you will now have uncontrolled boost.
Some people also play around with bleed orifices. Installing a bleed orifice in the hose that leads to the wastegate actuator reduces signal pressure, which allows more boost to develop. It's cheap and dirty, but it works. Finally, you can install a manual or electronic boost controller in place of the BCS, which will allow you to adjust the boost levels inside the car as you drive down the road, listening carefully for detonation.
Another favorite swap is installing a big-vane air meter (VAM). The VA M's job is to measure the airflow entering the engine. Based on the vane's position, it will tell the computer how much fuel to supply the injectors. Just as a carburetor can be too small on an improved engine, the vane meter can be too small to supply the engine with enough air. Using a Turbo Thunderbird/Mustang SVO big-vane meter will provide you with a greater air supply.
If you change the VAM, you need to swap in a new computer or chip. The best factory computer out there comes from a 1986 Mustang SVO (PE code). However, these computers are becoming scarce and demand upwards of $350 at swap meets. As an alternative, I 984 and 1985 SVO computers will also work and mate perfectly with the XR's wiring harness. You could also use a Turbo Thunderbird computer from a 1987 or 1988 model, but you will need to do some rewiring.
Another alternative would be to purchase a performance chip designed for the,XR. Superchips offers a chip that installs directly into the service port of the Ford EEC-IV computer wbich overrides the factory computer settings. Before you do any of this, however, install an intercooler.
Seriously power-hungry folks can upgrade the turbo to a hybrid unit that combines a T3-sized turbine mated to a T4 compressor. This combination allows the turbo to spool up with the speed of the standard T3 but generate the airflow of a big T4. If you went with a straight T4 unit, your turbo boost would not be available until a much higher rpm. You should also port the head and manifolds and install bigger valves. Also, for big horsepower, you need to upgrade your fuel injectors to larger-flow units.
Many folks have swapped out the standard T9 five-speed and installed a beefier TS fivespeed transmission. The T9 can be unreliable when horsepower exceeds stock levels, so it is best to upgrade. While the standard TS is good, the World Class TS is even better (more durable). You need to change the bell housing to one from either a Turbo Mustang, early Turbo Thunderbird, or late-model, 2.3-liter Mustang. The front of the driveshaft will also need to be modified to accept the new transmission.
The suspension on the XR is pretty good from the factory except that there is a lot of body roll. The recommended plan of attack for suspension tuning on the XR is to replace the struts and shocks with finer units. After that, install larger diameter anti-roll bars. Swapping in a 28mm front and 16mm rear bar will tighten things up considerably, and you can upgrade all the bushings to urethane for even tighter handling. New springs should come last and are really only necessary for fast road cars or autocross racers.
For those that have an early car, consider changing the 14-inch wheels to 15- or even up to 16-inch units with lower-profile tires. A seveninch-wide wheel with 205 tires is the maximum size recommended for the front, but the rear can take a 225. If you go to a 7.5-inch wide wheel, you need to make sure it has a 38mm offset and you must use stick-on weights. If you use standard wheel weights, they will hit the strut tube. All wheels must be hubcentric (hub centering flange of 63.5mm in diameter) and have a bolt pattern of 4x108mm.
If you want to compete with your XR, you have a couple of options, although the days of running the car in Trans-Am or IMSA are long gone. Unfortunately, the XR4Ti is not allowed to compete in the SCCA's nationally-recognized Improved Touring category because of its turbocharger, but local Regions may let it compete in !TE or another catch-all class.
There are more places to run in SCCA Solo IJ competition, as the car has been classed in both the G Stock and the E Street Prepared classes. In G Stock, the Merkur faces the Integra Type R and turbocharged Mitsubishi Eclipse, while in ESP it has to deal mostly with VS-powered pony cars as well as the Eclipse.
Merkur club support is fantastic. For those folks familiar with the shows at Carlisle, Penn. a large Merkur contingent meets during the All Ford Nationals. The group has more than 150 cars showing up each year for three days of fun and story swapping. This year, the All Ford Nationals was held June 2-4.
Is It for You?
The Merkur XR4Ti is a fabulous car by any right. The fact that good examples can be had for new-car down-payment money is even better. They may be hard to find, but once you bring one of these misunderstood cars into your family, you may find that all your cars become Merkurs.
A special thanks goes to Jason Smith, whose knowledge and expertise of the XR4Ti was instrumental in completing this article.
