Tips on how to make a Merkur XR4Ti faster, circa 2...

From Whence They Got here

Again within the early Nineteen Eighties, with Ford’s European darling, the Cortina, coming to the top of its lengthy and prolific manufacturing run, Ford wanted a automotive to fill the void that it could depart behind. The Cortina was a mid-sized automotive with somewhat boxy proportions and poor aerodynamic properties. With the gas disaster of the late ’70s nonetheless recent on everybody’s thoughts, Ford’s designers determined {that a} extra aerodynamic automotive must be designed to assist curb the gas urge for food. 

In September of 1981, Ford of Europe unveiled the Probe III idea. The Probe III seemed extra like a futuristic automotive from a film set than the seeds of a manufacturing automotive, because it was bedecked with rear wheel skirts, aero discs over the wheels, molded bumpers and a radi­cal-looking biplane rear wing. Nonetheless, all of those parts have been in response to Ford’s newly adopted aerodynamic mantra, and the idea automotive turned in a powerful 0.22 drag coefficient. The manufacturing model of this new automotive could be known as the Sierra.

The Sierra got here geared up with a four-wheel impartial suspen­sion, utilizing MacPherson struts up entrance and variable-rate coil springs mounted on trailing arms on the rear. Ford’s intention was for the automotive to fill as many sub-segments of the mid-size market as potential, so the Sierra was to come back in many alternative physique and drivetrain layouts, together with 4 doorways, three-door hatchbacks, four-speeds, five-speeds, automatics, V6s and V8s (South Africa solely). The highest-of-the-line Sierra was the XR4i mannequin.

Robert “Bob” Lutz, Ford of Europe’s chairman on the time, selected the three-door hatchback model of the Sierra line as the premise on which to construct a particular XR sport mannequin. Its three-door shell was additional revised to incorporate 4 pillars as a substitute of the same old two. The automotive got here geared up with the two.8-liter, 60-degree Y6 engine of Ford Capri fame, whereas the suspension was tuned utilizing a 26mm entrance and a 10mm rear anti-roll bar. Gasoline-pressurized shocks have been additionally employed in any respect 4 corners. 

Most discover­ably, the XR incorpo­rated the unconventional biplane rear spoiler from the Probe III present automotive, used upon the in­sistence of Bob Lutz and regardless of the criticism of the automotive press. This modification in styling would set it aside from the extra pedestrian Sier­ras–in addition to all different automobiles of its day. 

Ford of Europe had already had nice suc­cess in promoting its European automobiles stateside–most notably the 1970-’77 Mercury Capri and the 1978-‘ 80 Ford Fiesta–so Ford brass de­termined they’d an untapped market seg­ment for the likes of the XR sports activities sedan. U.S. consumers have been already flocking to the Mercedes 190, BMW 3 Sequence, Saabs, and Audis, so it was determined that the XR sedan would com­pete head-to-head with these automobiles on each worth and efficiency.

As they have been getting ready for the Sierra’s en­trance to the U.S. market, Ford discovered that Oldsmobile held the North American rights to the identify Sierra with their Cutlass Cierra, so a brand new identify was wanted.

There have been larger issues, nonetheless. As soon as the two.8-liter V6 was strangled with U.S. emissions tools, the XR was merely not highly effective sufficient to be a profitable competi­tor. Ford seemed to its company components bin for a substitute.

Happily, Ford of Detroit had a superb 2.3-liter, turbocharged, four-cylinder engine that was cuITently getting used within the Mustang SYO. The Lima unit, because the facto1y known as it, was an ideal selection for the U.S.-bound XR, because it was designed with U.S. emissions laws in thoughts. After some small modifications, reminiscent of dropping the intercooler, the engine was slated for XR use. The engine could be manufactured in Taubate, Brazil, then shipped to the Karmann manufacturing facility in West Germany the place the U.S.-bound XRs have been being assembled.

All that remained to be decided was a reputation for the automotive. Ford was going to market the XR via choose Lincolo-Mercury Deal­ers–an method that had labored effectively with the Capri–so Bob Lutz coined the identify Merkur (pronounced “Mare-coor”). Because the automotive was being in-built Germany, why not give the automotive a German identify? (Merkur means Mer­cury in German.) The Sierra XR4i could be­come the Merkur XR4Ti, with the ‘T” being added to characterize the turbocharged engine.

When the Merkur XR4Ti arrived on U.S. shores within the fall of 1984, the automotive press obtained the brand new automotive very effectively. The take a look at driv­ers cherished the ability and velocity of the Merkur, which soundly outperformed its competitors in straight-line efficiency with 0-60 occasions within the mid-seven-second vary and a high velocity of near 130 mph. It was the quickest Ford in the marketplace, in addition to essentially the most aerody­namic with a 0.32 drag coefficient. The automotive was effectively balanced, too, with a 53-percent entrance and 47-percent rear weight distribution.

The one criticisms have been its tendency to lean within the corners, the unrefined engine, lack­luster brakes, and naturally, its radical styling. Most writers both cherished it or hated it; there was no center floor. The delicate dealing with was blamed on the producer, which was accused of as soon as once more failing to deliver over a automotive from Europe unspoiled. The spring charges have been certainly altered from the Euro specs, and there was the added weight imposed by the U.S. security necessities (five-mph bumpers. strengthened door beams, and so forth).

The engine had already obtained fairly a little bit of consideration to cut back its harshness. The two.3-liter engine, like all inline fours, is inherently out of stability. Because the engine could not be redesigned on the within, engineers targeted on the exterior parts. They discovered that the ancillary parts have been a serious supply of vibration, so each was evaluated and harmonically measured in order that new parts or mounting brackets might be designed to cut back vibration. Engineers additionally developed hydraulic engine mounts that may take up any remaining vibration. Ford clearly thought they bought it proper however the press thought in any other case.

Nonetheless, the engine featured 175 horse­energy when mated to a T9 five-speed trans­mission. The automated automobiles have been detuned to 145 horsepower, as a result of the C3 computerized. which often spent its life underneath the ground pans of sedate four-cylinder Fairmonts and Granadas, was not robust sufficient to deal with the 195 ft.fibs. of torque. 

All Merkurs got here absolutely geared up with air­ conditioning, AM/FM stereo cassette, and full instrumentation, which included a 7000-rprn tach and turbo enhance gauge. The speedometer solely went as much as 85 mph–the numbers have been lacking previous that time–though in late 1988 the velocity­ometer was modified and eventually went all the way in which to 150 mph. Service lights have been current for the remainder of the important indicators. 

4-wheel-disc brakes, which have been very fashionable with European sports activities sedans, have been to not be discovered o the Merkur. As an alternative, it got here geared up with 10.2-inch disc brakes up entrance and 10-inch drum brakes on the rear. This setup damage the Merkur in side-by-side braking checks with its European rivals. One other downside stemmed from the 14-inch wheels shod with slim Pirelli P6 tires. They have been marginal at finest. This downside was addressed in 1987, when the Merkur was switched to 15-inch rubber.

Choices on the Merkur included a moonroof, leather-based seats, heated seats (solely obtainable in northern states and Canada), energy home windows and door locks (normal in late 1988), and aforementioned computerized transmission. In late 1988, cruise management was added as an possibility. The automotive was priced at round $17,000, which was costly so far as Fords go, however a cut price in comparison with its predominant rivals. Sadly, the estimated gross sales forecast of 20,000 models close to was by no means met.

When the smoke from all of the hype cleared on the finish of 1985, Lincoln-Mercury was left surprised. The place have been the consumers? The focused buyrer was an prosperous thirtysomething male–not the standard one who would stroll via the door of a Lincoln-Mercury dealership. The salesmen often knew much less concerning the XR4Ti than the shoppers wanting to have a look at one, and the automotive seemed completely misplaced sitting subsequent to a Lincoln City Automobile. (One can solely think about how the City Automobile clients felt trying on the XR4Ti, with its wings and all. “Please do not try this to my City Automobile,” was in all probability their thought.)

The pattern was a bit of higher in 1986, with extra XR4Tis leaving the showroom ground. Nevertheless, gross sales have been nonetheless beneath the forecasts, and the BMW sedans and Mercedes 190 have been outselling the XR4Ti by the tens of 1000’s.

Lastly, in late 1987, some enhancements have been made. Together with me bigger wheels, the grey plastic physique cladding and bumpers grew to become obtainable in physique colours for black and white automobiles solely. The brand new look was spectacular, however the hemorrhaging was unabated.

For 1988, the XR4Ti misplaced its biplane spoiler to a extra conservative single unit; shopper surveys had indicated that the biplane spoiler was a bit of too obnoxious. Bob Lutz, the so-called Father of the Merkur, must lose this battle. Extra subdued colours additionally grew to become avail­in a position together with conservative BBS-style lattice wheels that Ford intro­duced halfway via the 1988 mannequin 12 months.

1989 was the final mannequin 12 months for the XR4Ti. It appeared that each one the styling adjustments had failed to enhance sale–-America as an entire did not know what to think about the automotive. 

One other Merkur, the Scorpio, which was based mostly on the European Granada, was launched in 1988 to go with the XR4Ti. It was a extra conservative four-door automotive with a 2.9-liter Cologne V6, nevertheless it, too, did not promote within the projected numbers. For 1990, your entire Merkur line was dropped.

Win on Sunday, Promote on Monday?

Among the many lots within the U.S., the preferred types of motor racing are in all probability NASCAR inventory automobiles and IRL/Champ open-wheel automobiles. With NASCAR specifically, the established relationship between successful races on Sunday and promoting these automobiles on Monday has lengthy been a cornerstone of the American racing scene. It is unlucky that this philosophy did not carry over for the XR4Ti, which posted a num­ber of street racing wins to its credit score.

In 1985, the hotly contested Group A RAC British Saloon Automobile Cham­pionship was gained by Andy Rouse’s workforce of their U.S.-market XR4Ti. By way of particular homologation papers introduced by Ford’s competi­tion division, the automotive was referred to collectively as a Merkur and Si­erra; due to this fact, the U.S. automotive may compete on English soil.

The automotive was primarily a U.S. home-market automotive specifically fitted with a big intercooler, Getrag five-speed gearbox, four-wheel disc brakes, 16-inch BBS wheels, new springs, limited-slip differential, and modi­fied turbo enhance settings. Rouse estimated the automotive generated 300 horse­energy, all from the two.3-liter engine obtainable to U.S. customers.

In 1986, Jack Roush Racing entered three specially-prepared XR4Tis within the SCCA’s Trans-Am street racing collection. These automobiles employed the identical fundamental design structure because the XR4Ti, with rear-wheel drive and a 2.5-liter, four-cylinder turbo engine, however they rode on a pure-race-car, tube-frame chassis. Nevertheless, the automobiles did keep the sleek-looking styling of the XR4Ti. This mixture propelled Roush’s workforce to the Trans-Am championship title in 1986 and 1987. 

In 1988, Roush switched efforts to the IMSA GTO collection and con­tinued successful championships with the XR till 1989, when the workforce changed the Merkur with the Cougar. 

Shopping for a Merkur XR4Ti

Finding a XR4Ti in your native paper is akin to discovering a four-leaf clover in your yard; it occurs, however it’s essential to look carefully. Happily we live within the info age, with the Web giving us many extra choices; a fast take a look at the net classifieds will yield greater than a dozen automobiles nationwide. XR4Tis are priced from $500 for a tough one to $4000 for a mint, low-mileage ’89. Most automobiles are priced round $1500 to $2000, and so they provide super worth for the cash. 

For those who do not keep and restore automobiles your self, you’ll have to learn the way. You can be unlikely to discover a mechanic that absolutely understands these automobiles, and Ford has all however deserted them. A number of the components you want are additionally now not obtainable from Ford, so you have to depend on the small cottage trade that helps these automobiles. The Web shall be invaluable to you as an proprietor, as the probabilities· are good that somebody on the market has already addressed the problems you encounter. There are numerous wonderful Websites and help teams simply ready for brand spanking new house owners.

The XR4Ti is offered in mannequin years 1985 to 1989, with roughly 42,000 models produced complete. You’ve got your selection of five-speed transmis­sions or three-speed automatics, and the automobiles are categorised into three dis­tinct teams: The primary group is the early automobiles of 1985 and 1986; the second is the 1987 automobiles; and the third is the 1988 and 1989 fashions.

The Early Vehicles

The 1985 and 1986 XRs are simply acknowledged by their biplane spoiler, small 14-inch rotary-phone-dial wheels, and grey decrease physique cladding. An ’86 will be additional distinguished by its third, high-mounted brake mild.

The early automobiles are liable to quite a few maladies distinctive solely to them. The early forged exhaust manifold tends to develop stress cracks, however they are often welded again up. Nonetheless, you’re higher off lo­cating a manifold from a later automotive, as it’s reputed that the later manifold additionally flows a Iittle higher.

In the identical space of the exhaust, the catalytic converter on the early automobiles was topic to a manufacturing facility recall. Chances are high that any XR on the market on the market has had the issue fastened, nevertheless it nonetheless is sensible to test this out by calling the vendor.

The highest of the dashboard will crack. That is to be anticipated on an early automotive. A brand new sprint pad will be fitted to cover the crack, or you possibly can re­place the sprint with one from a later automotive.

The early automobiles even have retractable radio antennas mounted within the left rear fender, and if they don’t seem to be often cleaned, these can fail to function. These automobiles have been additionally topic to extra elec­trical gremlins than the later automobiles. One troublesome half was the oil stage sensor on the dipstick giving a false low-oil studying.

Typically, the gremlins boil all the way down to a foul relay or cor­roded terminal con­nections that may be cleaned up with some wonderful emery material and WD-40. 

The ’87 Fashions

1987 was a transitional 12 months for the XR4Ti. The automotive nonetheless carried the biplane spoiler, nevertheless it signaled the start of Ford’s XR tone-down. New 15-inch wheels have been fitted that featured eight spokes–4 spokes resting excessive of the opposite 4. (Individuals generally name these the “pie-spoke” or “spatula” wheels.) The early ’87 automobiles nonetheless used the identical retractable antenna discovered on the 1985 and 1986 automobiles.

Whereas the late 1987 automobiles integrated some-what improved electronics, they nonetheless had their share of defective switches and re­lays. For essentially the most half, nonetheless, these and later automobiles have higher digital reliability than the earliest ones. The opposite main change concerned incorporating the radio antenna into the rear window glass defrost grid.

Additionally distinctive to those automobiles was the obtainable monochromalic paint scheme for white and black automobiles. This selection incorporates body-colored facet cladding that arguably improves the seem­ance. A brand new dashboard was launched which was much less more likely to crack, whereas the big speaker grill on high of the sprint, which appeared to be the origin of the cracks on the early automobiles, was eliminated. The inside material materials was additionally upgraded to the next high quality material. Additionally, the sooner troublesome Ford rack-and-pinion steering was changed with a brand new aluminum ZF-made rack.

The Later Vehicles

Purists could argue that these are usually not true Merkur XR4Tis–an actual Merkur will need to have the biplane spoiler. Their single rear spoiler and extra sedate look establish the 1988 and 1989 automobiles, whereas new colours have been launched together with brown facet cladding for gold and bronze automobiles. Purple was added to the quick checklist of monochromatic colours.

Early 1988 fashions rode on the 15-inch “spatula” wheels, which have been changed halfway via the 12 months by 15-inch, BBS-style lattice rims. Totally different inside colours have been additionally added–Raven Black and Spice Brown–with matching sprint colours. These dashes match the sooner automobiles, so if you’re boneyard looking for a brand new sprint, they’re going to work. The speedometer was additionally uprated to learn 150 mph as a substitute of 85 mph. 

To mount the brand new, single spoiler, Ford redesigned the rear hatch and widened the window glass. That is essential to know as a result of if you buy a later automotive and attempt to set up a biplane spoiler, it’ll relaxation partially on the rear glass. The higher method could be to find an early rear hatch with the biplane spoiler already fitted. This, nonetheless, presents one other small downside that must be addressed: The radio antenna for the later automobiles was the rear-window defrost grid. To ensure that the antenna to work on the older hatch, you’ll need to put in the digital isolator field into the hatch for the antenna grid. 

One other later automotive illness is the cable that runs out of the headliner to the antenna connection on the hatch. It tends to interrupt after repeated openings and closings of the hatch. 

All Vehicles

XR4Tis are usually not liable to rust, however there are just a few areas that may trigger issues that principally outcome from poor upkeep. For ex­ample, the drain holes on the underside lip of the rear hatch can get clogged, inflicting the hatch to rust. Hold the holes clear.

Additionally, rust can type on the backside of the doorways, due to dust that will get trapped behind the plas­tic cladding. Holding the door drain holes clear and checking for free cladding will assist keep away from the issue. The rivets that maintain the cladding on may break, offering an ingress level for dust and salt. New rivets can be found. (The riv­ets are situated behind the coloured strip on the high of the cladding.) 

Interiors are likely to collapse, as leather-based seats will break up, and headliners will fall down. Re­pairs reminiscent of these will be carried out by a reliable proprietor or upholstery store. The rear taillight gaskets additionally fail and permit water to seep into the spare tire effectively. This causes the taillight terminals to corrode, which is able to in­troduce extra issues. Substitute these gaskets on the first signal of a leak.

The headlight lenses, that are fabricated from plastic, are likely to get cloudy with age, however they are often cleaned up with a very good plastic polish. Notice that the XR4Ti lights are usually not that vivid to start with. A greater resolution, however not a per­fect swap, is to put in the European-style headlights. These will deliver the lighting as much as fashionable requirements.

The two.3-liter engine is a really sturdy pow­erplant, even when it’s turbocharged. Regu­lar oil adjustments and upkeep will go a good distance towards longevity, and the city legend about turbo engines needing a brand new turbo at 60,000 miles is unfaithful.

The T3 turbo unit is sturdy, supplied the proprietor does not run the automotive arduous up till the purpose when the engine is turned off. This ac­tivity will shorten the lifetime of the unit consid­erably, because the oil is not allowed to flow into and funky down the engine.

One other space to regulate is the timing belt, which must be changed each 50,000 miles. There is no injury should you do not change it (non-interference engine), however you’ll need a tow truck to get house if one ought to snap.

Each mannequin 12 months XR4Ti can be suscep­tible to radiator issues, as the top caps are fabricated from plastic that tends to leak. They are often repaired with some gasket sealer however they’ll in all probability nonetheless weep sometimes. (The coolant stage will should be monitored religiously.) New all-metal radiators can be found for round $400, and be aware that the radiator for the automatics is totally different from the five-speed’s. Additionally take be aware that the 1989 automobiles used a radiator that’s distinctive to that mannequin 12 months which can’t be changed with one from an earlier automotive.

All XRs can endure from hydraulic engine mount failure. As talked about beforehand, the mounts are there to dampen engine vibration, and as soon as they fail, you’ll start to really feel robust engine vibrations-with every part buzzing within the cabin. If that’s the case, look underneath­neath the engine on the oil pan. Whether it is resting on the steering rack or the engine seems tilted, you have got unhealthy engine mounts. Substitute the transmission mount while you’re at it.

One other quite common supply of vibration is the RotoFlex (Guibo) coupling. This donut­formed piece of rubber is a part of the driveshaft meeting, and over time, it’ll crack and begin to lose bits of rubber. For those who expertise a robust vibration as you are taking off, which will get worse as you go sooner, you in all probability want a brand new donut.

Ford will attempt to promote you a whole new driveshaft for this restore. Do not do it. The do­nuts can be found from different sources for about $50. In actual fact, some mid-to-late ’80s BMW 5 Se­ries sedans use an analogous piece. (Examine the BMW piece in opposition to the Merkur one to verify the scale are comparable.) Whilst you’re working across the driveshaft, test its middle help bearing. If there may be motion larger than 3/s inch, you’ll need a brand new middle bearing.

The unique-style camshaft cowl gasket fails often, sending oil down the block, which is a giant fireplace hazard round a sizzling turbo. Substitute the gasket with a brand new neoprene gasket that’s de­signed for a 1992- ’93 Ford Ranger pickup. This improved gasket has metal shim-limiting washers across the mounting holes, which maintain the bolts from being over tightened.

The gas injectors are additionally liable to leakage across the sealing o-rings and plastic gas injec­tor physique. That is additionally a very good supply for a fireplace. (Sure, XR4Tis are liable to burning up if not maintained–maintain a fireplace extinguisher on board.)

The excessive warmth of a turbocharged engine at­tacks something fabricated from rubber or plastic underneath the hood, so test all vacuum strains and gas strains and change these components periodically. Even the battery will endure from the warmth.

If the automotive appears to be idling erratically, first test the situation of the ignition system (OEM parts are really useful) and vacuum strains, after which test the throttle place sen­sor. Over time, they require adjustment utilizing a voltmeter. You also needs to clear the throttle physique and idle velocity controller with carb cleaner.

One other electrical element that may fail unexpectedly is the ignition module-the en­gine will die and never restart. Typically, should you enable the engine to chill down, it is possible for you to to restart the automotive. The prudent XR proprietor will at all times carry a spare module and the particular ignition wrench wanted to put in it. All the time use a Motorcraft substitute half. 

The coolant temperature sender (situated on the underside underside of the consumption manifold) can also fail. Ford provides a brand new half, generally known as the “purple-ring sender.” If the temperature appears too low, likelihood is you have got a foul sender or maybe a clog by the T-fitting close to the sender.

If the steering wheel twitches or shake barely as you drive down the street, likelihood is good that the control-aim bushings want renew­ing. Changing these will tighten up a free entrance finish significantly. Do not blame warped rotors on the control-arm bushings, nonetheless, as the identical sort of steering wheel motion will be felt underneath braking if the rntors are warped.

Making Them Quicker

One of many nice issues a couple of turbocharged automotive is the unbelievable horsepower potential that’s obtainable, bolt-on, for cheap prices. To get the identical efficiency from an naturally-aspi­rated engine would require an intensive engine teardown and decreased drivability at something aside from full-throttle operation. A turbo automotive is like Jekyll and Hyde, with sedate traits off enhance and ferocious tenacity on enhance. How briskly you need to go is expounded to how a lot enhance you possibly can safely feed the engine.

One of many first issues it is best to do is change the inventory air filter. Utilizing a very good aftermarket filter, reminiscent of a Okay&N, will assist the engine pull in additional air. One other method could be to make use of a cone-style filter as a substitute of the standalone housing. In doing this, it would be best to construct an open housing that shields the air consumption from the turbo’s warmth.

The later inventory exhaust manifold is fairly good, though stainless-steel tubular headers are higher however costly. Your aim is to maintain the exhaust fuel velocity excessive on its strategy to the turbo housing. It will make the turbine spin sooner,  thus creating extra obtainable enhance. Putting in a three-inch downpipe to the converter may even enable the turbo to spool up sooner as a result of it is not scuffling with exhaust backpressure. 

On the identical theme, putting in three-inch pipe all the way in which out the again via a straight-through muffler may even enhance the turbo’s efficiency. The larger the pipe, the higher. That is simply the alternative of an atmospheric engine, which requires some backpressure to enhance exhaust scavenging.

Everybody is aware of that getting loads of energy from a naturally-aspirated engine requires a wholesome little bit of carry and length of the cam profile, which creates a really lumpy idle. It might sound cool whenever you hear a giant V8 lumping alongside at a stoplight, however around-town driving is horrible.

In distinction, the turbo engine hates valve overlap. A fairly-mild cam is all of the engine must create energy; putting in a race cam into your turbo engine kills its capability to create enhance till a lot increased engine speeds are reached.

There are, nonetheless, some good aftermarket cams on the market should you do some procuring. Modem Efficiency a pleasant curler cam for the two.3-liter engine, though a less expensive possibility exist and is definitely discovered at a junkyard: the curler cam from an early-’90s Ford Ranger pickup. It is marginally higher than the inventory five-speed XR cam, though the principle profit is the substitute of the XR’s hydraulic cam with a smoother curler setup.

As talked about beforehand, the two.3-liter engine is just not a really refined piece. The engine and all of the ancil­lary parts are likely to make some clanking noises and vibration, which might idiot the knock sensor into assume­ing the engine is struggling detonation. The pc will retard the timing and kill energy.

The answer is easy: pull the wire off the knock sensor. You will want to pay attention for detonation sooner or later, and will again off the fuel and timing-just as you probably did earlier than the appearance of computer-controlled engines–if any unhealthy noises are heard.

If you’re a complicated me­chanic, you possibly can set up a knock­-sensing laptop made for the Saab 9000 Turbo. The Saab APC com­puter is designed for knock sensing on a turbocharged engine, so as a substitute of retarding the timing, it’ll bleed off some enhance, utilizing its personal boost-control solenoid, till the knocking stops.

When the turbo compresses air, the method creates warmth. A sizzling consumption cost is not going to professional­duce loads of energy as a result of the air cost shall be much less dense. You need to cool the cost, earlier than you introduce it to the engine, by utilizing an intercooler.

An intercooler is actually a radiator for the compressed air; sadly, the XR didn’t come intercooled from the manufacturing facility. Nevertheless, there may be proof on the 1989 automobiles that Ford was going so as to add an intercooler, as a result of they moved the radiator overflow from the passenger’s facet of the engine compartment to the motive force’s facet.

A well-liked swap is putting in a Turbo Thunderbird/Mustang SVO-style intercooler. The one downside with this swap is that there isn’t any supply of recent, cool air to go via the intercooler; you’ll discover the SYO has a hood scoop instantly feeding the intercooler, however the Merkur has none. Nevertheless, aftermarket suppli­ers have designed intercoolers particularly for the XR that do not require reducing holes within the hood of your automotive.

The important thing to a very good intercooler is, clearly, to chill the cost, nevertheless it should additionally maintain the turbo enhance stress drop to a minimal. An ineffi­cient intercooler will rob as a lot energy as you hoped it could generate.

The wastegate’s job is to vent off exhaust gases so the turbine is not going to spin as quick, thus decreasing enhance. On the XR, the enhance management solenoid (BCS), which is ruled by Ford’s EEC-IV laptop, indicators the wastegate actua­tor to carry most enhance to 10 psi when rpm is beneath 4200. Above 4200, enhance is allowed to climb to 15-plus psi. (Notice that this solely applies to five-speed automobiles; the enhance on automobiles with an au­tomatic transmission by no means rises previous 10 psi).

A straightforward strategy to achieve energy at decrease engine speeds is to take away the vacuum strains going to the BCS and join them collectively, successfully bypassing the solenoid altogether. This may be harmful, nonetheless, as a result of you’ll now have uncontrolled enhance.

Some individuals additionally mess around with bleed orifices. Putting in a bleed orifice within the hose that results in the wastegate actuator reduces sign stress, which permits extra enhance to develop. It is low cost and soiled, nevertheless it works. Lastly, you possibly can set up a handbook or digital enhance controller rather than the BCS, which is able to let you alter the enhance ranges in­facet the automotive as you drive down the street, lis­tening fastidiously for detonation.

One other favourite swap is putting in a big-vane air meter (VAM). The VA M’s job is to measure the airflow getting into the engine. Primarily based on the vane’s place, it’ll inform the pc how a lot gas to provide the injectors. Simply as a automotive­buretor will be too small on an improved engine, the vane meter will be too small to provide the engine with sufficient air. Utilizing a Turbo Thunderbird/Mustang SVO big-vane meter will give you a larger air provide.

For those who change the VAM, it’s essential to swap in a brand new laptop or chip. The most effective manufacturing facility com­puter on the market comes from a 1986 Mustang SVO (PE code). Nevertheless, these computer systems are be­coming scarce and demand upwards of $350 at swap meets. Instead, I 984 and 1985 SVO computer systems may even work and mate per­fectly with the XR’s wiring harness. You would additionally use a Turbo Thunderbird laptop from a 1987 or 1988 mannequin, however you’ll need to do some rewiring.

One other different could be to buy a efficiency chip designed for the,XR. Tremendous­chips provides a chip that installs instantly into the service port of the Ford EEC-IV laptop wbich overrides the manufacturing facility laptop settings. Earlier than you do any of this, nonetheless, set up an intercooler.

Critically power-hungry of us can improve the turbo to a hybrid unit that mixes a T3-sized turbine mated to a T4 compressor. This combi­nation permits the turbo to spool up with the velocity of the usual T3 however generate the airflow of a giant T4. For those who went with a straight T4 unit, your turbo enhance wouldn’t be obtainable till a a lot increased rpm. You also needs to port the top and manifolds and set up larger valves. Additionally, for giant horsepower, it’s essential to improve your gas in­jectors to larger-flow models.

Many of us have swapped out the usual T9 five-speed and put in a beefier TS 5­velocity transmission. The T9 will be unreliable when horsepower exceeds inventory ranges, so it’s finest to improve. Whereas the usual TS is nice, the World Class TS is even higher (extra sturdy). You might want to change the bell housing to at least one from both a Turbo Mustang, early Turbo Thunderbird, or late-model, 2.3-liter Mustang. The entrance of the driveshaft may even should be modified to simply accept the brand new transmission.

The suspension on the XR is fairly good from the manufacturing facility besides that there’s a lot of physique roll. The really useful plan of assault for suspension tuning on the XR is to exchange the struts and shocks with finer models. After that, set up bigger ­diameter anti-roll bars. Swapping in a 28mm entrance and 16mm rear bar will tighten issues up significantly, and you’ll improve all of the bush­ings to urethane for even tighter dealing with. New springs ought to come final and are actually solely nec­essary for quick street automobiles or autocross racers.

For those who have an early automotive, contemplate altering the 14-inch wheels to 15- and even as much as 16-inch models with lower-profile tires. A seven­inch-wide wheel with 205 tires is the utmost dimension really useful for the entrance, however the rear can take a 225. For those who go to a 7.5-inch huge wheel, it’s essential to ensure that it has a 38mm offset and you have to use stick-on weights. For those who use stan­dard wheel weights, they’ll hit the strut tube. All wheels should be hubcentric (hub centering flange of 63.5mm in diameter) and have a bolt sample of 4x108mm.

If you wish to compete together with your XR, you have got a few choices, though the times of operating the automotive in Trans-Am or IMSA are lengthy gone. Sadly, the XR4Ti is just not allowed to compete within the SCCA’s nationally-recognized Improved Touring class due to its tur­bocharger, however native Areas could let it compete in !TE or one other catch-all class.

There are extra locations to run in SCCA Solo IJ competitors, because the automotive has been classed in each the G Inventory and the E Road Ready courses. In G Inventory, the Merkur faces the Integra Sort R and turbocharged Mitsubishi Eclipse, whereas in ESP it has to deal principally with VS-powered pony automobiles in addition to the Eclipse.

Merkur membership help is unbelievable. For these of us aware of the reveals at Carlisle, Penn. a big Merkur contingent meets in the course of the All Ford Nationals. The group has greater than 150 automobiles exhibiting up every year for 3 days of enjoyable and story swapping. This 12 months, the All Ford Na­tionals was held June 2-4. 

Is It for You?

The Merkur XR4Ti is a wonderful automotive by any proper. The truth that good examples will be had for new-car down-payment cash is even guess­ter. They might be arduous to search out, however when you deliver considered one of these misunderstood automobiles into your loved ones, it’s possible you’ll discover that each one your automobiles change into Merkurs.

A particular thanks goes to Jason Smith, whose information and experience of the XR4Ti was instrumental in finishing this text.