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'98-'01 2.5RS Article, History, Specs, Racing etc.
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Old 10-15-2004, 05:51 AM   #1
subrew
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Car: 2004 Sti, silver/gold
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Default '98-'01 2.5RS Article, History, Specs, Racing etc.

A couple years ago I wrote an article for Grassroots Motorsports Magazine. It was a profile on the 2.5RS, covering '98 to '01 models. I believe it was published in the March 2002 issue (GRM usually has back issues) if you want to pick up a printed copy. Quite a few people from this board had their cars pictured in it (mine included.) Anyways, I'm re-organizing my web site, and just thought I would post the text of the article as a reference for 2.5RS owners. (It is still timely, except for the suggestions at the end for prepping a 2.5RS for national level STS competiton, where the prep level has sky rocketed since the article was written.)

I hope it proves useful.

---start---

Subaru's Factory Hot Rod: Impreza 2.5RS

Ancestry

A few years ago, the sight of a Subaru at an autocross meant that some soccer kid's mom got lost on her way to the field. Sure, there were a few sporty Subarus in the '80s, like the turbo-infused GL10 sedan and wagons. Same with the flying wedge known as the XT and XT6 and with the space-age SVX, featuring Subaru's largest production engine to date.

Still, it wasn't until the introduction of the Legacy Turbo in 1991, born from Subaru's assault on Group A rallying, that motorsports enthusiasts had something to shout about. Names like Prodrive, 555, and Colin McRae soon found their way into idle bench-racing conversations. It wasn't long before these sound bites could be backed up, after consecutive British Rally Championship titles in 1991 and 1992, and a World Rally Championship win in the 1993 rally of New Zealand.

Hoping to build on their quick success, Subaru and Prodrive, the British-based tuning company headed by Dave Richards, utilized a new weapon in the form of the Impreza. First offered to car buyers in Japan in 1992, the Impreza replaced the staid and trusty Loyale in the United States in 1993.

The Impreza didn't bring much improvement in performance, however; the 110hp, 1.8-liter engine had to work hard to move the new car's extra weight. Subaru didn't stand a chance in the flourishing sport compact wars of the time. Worse yet, American enthusiasts drooled over copies of British road test magazines featuring comparisons of the new Impreza WRX with the Lancia Delta Integrale and Escort Cosworth. Faring quite well against these legendary rally specials, American enthusiasts could only fill their need by building 1/24th-scale models of Subaru's hottest offering to date.

A step in the right direction was made in 1995, when an optional 2.2-liter engine-as used in the Legacy-became available. Even a two-door coupe filled out the Impreza range. When optioned with just the right accessories, one could almost see oneself in a rally blue Impreza 2.2 Coupe, hustling around a gravel road, clearing tracks for would-be followers.

It was during the summer of 1997 when word of a "real" performance car from Subaru hit the streets. Word had it that a sporty version of the Impreza would be out. It wouldn't be a WRX, but it would offer more power, rally-inspired styling, and Subaru's now-legendary all-wheel-drive system (as Paul Hogan proclaimed in every television spot of the time).

Enter the 1998 Impreza 2.5RS. Featuring scoops and vents galore, a radiator intake large enough to swallow any rally photographer's camera, and a wing that would impress even at a hot import car show, Subaru finally had a car that automotive enthusiasts could get excited about.

Though certainly not a WRX with no giant top-end power rush, the 2.5-liter Impreza instead offers big hunky amounts of mid-range pulling power. Short ratios keep the driver busy, and lend a real sense of exhilaration when snipping up through the gears. The rally-inspired chassis speaks volumes on the road, soaking up large road confusions without a hint of instability.

It's that stability that makes the RS such a good base for an autocross or rallycross car; it won't take a driver long to get comfortable with the car. Unfortunately, the RS hasn't had a chance to show itself in stock-class autocrossing, with the current state of competition in G Stock, but has proven to be a winner in the hotly contested Street Touring arena. Ditto at rallycross events cropping up around the country. Box-stock RSes can compete for outright wins against genuine SCCA Pro Rally machines.

How to Spot Them

Subaru first introduced the 2.5RS in late 1997, as a 1998 model, selling less than 800 units. The easiest way to spot a '98 is to look for gold-colored, five-spoke wheels, and standard Impreza front bumper cover with small rectangular fog lights. Four colors were offered, with Brilliant Red, Rally Blue Pearl, and Midnight Black Pearl being the most popular. A very small number of Acadia Green RSes came out during the car's first month in production. Inside, '98 models have black-faced instruments pulled from the standard Impreza, but unique seats feature light gray cushions with brightly colored graphics. Under the hood, 1998 models were the only RSes to feature the DOHC engine.

Having sold less than 1,000 units in 1999, Subaru decided to add some boy-racer looks to the RS, including a new front bumper cover with large, round fog lights. The gold wheels were replaced with silver, of the same design. Also new on the outside, was the addition of two colors, Aspen White and Silverthorn Metallic-the latter proving quite popular.

Inside, new white-faced gauges matched up with racy red stitching on the leather-wrapped steering wheel and gearshift knob. Seats now used a less flashy checkerboard pattern in the cushion. The biggest mechanical change of the year consisted of the new SOHC Phase II engine.

Big news for 2000 was the introduction of the four-door RS to the lineup, whose only distinguishing exterior feature was the smaller L-grade rear spoiler. New six-spoke wheels were used throughout the broadened RS line, while a new darker Sedona Red and Blue Ridge Pearl came on board, with white, black and silver remaining popular. Inside, government-mandated child-restraint mounts make it easier to install a racing harness. Mechanically, a new air mass meter system was used, similar to that of the other 2.2-liter Imprezas.

2001 was really a carryover year for the RS, with only minor interior upgrades, such as carbon fiber dash accents offered as standard, and no major mechanical changes.

All the Specs

Two different versions of the 2.5-liter engine are used in the 2.5RS. Both use the same 99.5mm bore and 79.0mm stroke, resulting in a large (for a four-cylinder) 2,457 cubic centimeters. Power is rated at 165hp at 5,600rpm with torque weighing in at a meaty 162 lb/ft at 4,000rpm for the DOHC, and 166 lb/ft at 4,000rpm for the SOHC engine.

For 1998 model years, the existing DOHC engine used in the Legacy line, was put into service. It features four cams-two per bank-operating 16 valves. 1999 through 2001 models have what is referred to as Phase II engines, which feature a few internal changes aimed at solving durability issues, and of course different cylinder heads featuring single overhead cams per bank. These cylinder head changes were aimed at reducing friction, increasing economy, and improving torque.

Both engines use a die-cast aluminum block with cast in iron liners. The crankshaft literally fits between both halves of the engine, being supported by five large plain shell bearings that transmit forces horizontally into the block. Since horizontally opposed four-cylinder engines have such good inherent balance, the crankshaft webs are quite narrow, and have a fillet-style roll on their edges, increasing stiffness. DOHC engines featured the thrust bearing on the #3 main, while Phase II engines have it on the #5 main, aimed at reducing the tendency for deflection at elevated revs.

Connecting rods follow a standard H-beam pattern, with a thin inner web, and slim main caps. In an attempt to reduce friction, DOHC engines used a skirtless piston that literally has no skirt below the lower ring land. These engines have a tendency to produce piston slap, which can lead to broken lower ring lands. Phase II engines use a more conventional piston, featuring a full-length slipper skirt.

As mentioned before, the biggest changes came about in the area of cylinder heads. DOHC engines feature two cams per bank, operating directly on solid lifters. Phase II engines use a single cam per bank, operating two rocker arms per cylinder head. Y-shaped rocker arms operate the exhaust valves, while conventional finger arms operate the intake valves. Both engines use sixteen stainless steel valves, measuring 1.420 inches for intake and 1.240 inches for exhaust head diameters.

A tried-and-true pentroof combustion chamber is used, with a single center-mounted spark plug per cylinder. Compression is set at 9.7:1 on both engines, allowing the use of standard grade fuel.

Subaru made quite a few changes to the air metering system through the years. 1998 models use a hot wire mass air flow meter, while 1999 models use a hot film sensor. MAF sensors measure the density of the incoming air across the wire or film, and convert this into an electrical signal. From 2000 on, Subaru reverted to the manifold absolute pressure (MAP) system as used on the 2.2-liter engine. This system measures the air intake temperature and calculates the weight of air based off of volumetric efficiency maps stored in the management computer.

Both engines use a one-piece cast aluminum air intake plenum, featuring long runners for greater mid-range power. A 60mm throttle body is used on both engines, mounted directly aft of the intake plenum.

The exhaust system uses tubular steel header pipes, featuring a two-into-one design that merge into a somewhat strangled collector flange just before the first catalytic converter. Two oxygen sensors are used that work together to determine if the air-fuel mixture is consistent throughout the system. Exhaust tubing measures 2 inches in diameter and features a small resonator up front, with a large baffle-style muffler mounted at the rear of the car.

Putting that extra grunt down to the road, is Subaru's famous full-time all-wheel-drive system. Starting with either a 5-speed manual transmission or 4-speed automatic, Subaru uses a center differential for primary torque split. An open front differential is used on all models, with an open rear diff used through 1999, and a limited-slip rear diff on 2000 and later models. That rear differential is the venerable Hitachi R160, used for years in cars such as the Datsun 510.

The 5-speed transmission features dual cone synchronizers on second, third, and fourth gears, with a stronger mainshaft than 2.2-liter transmissions. A shorter throw shifter features a solid shaft for more positive engagement. Inside the bell housing, a 220mm clutch disc is hydraulically operated, and features a fluid damper between the master cylinder and operating cylinder for smoother operation.

On manual-equipped cars, the all-wheel-drive system uses a viscous coupling-type center differential, that splits torque 50/50, front to rear. As a wheel begins to slip, plates inside the viscous coupler begin to rotate at different speeds. This quickly shears, heats, and thickens the contained fluid in the coupler, causing power to be distributed to the other wheels.

On automatic-equipped machines, Subaru uses the 4EAT system, which normally runs in a 90/10 front to rear split. Since the 4EAT system runs in an "active" mode, the transmission's ECU will vary the torque split depending on what the car is doing at any given time. Torque can be sent to the rear under hard acceleration, or sent up front during heavy braking.

Underneath the front of every 2.5RS lie steel lower control arms, mounting to MacPherson struts. Manufactured by KYB, these struts are in fact the same as found on WRX Version III models sold in Europe and Japan, and feature a 22mm shaft mounted to rubber isolated upper strut bearings. Two mounting bolts locate the strut to a cast iron hub, with an eccentric "crash" bolt in the upper hole, used for camber adjustment.

In back, two lower parallel links and a trailing arm mount to a MacPherson strut. Again, rubber isolated strut bearings are used, and there is no provision for camber adjustment; but an eccentric mounting bolt is provided for adjusting rear toe.

Long travel coil springs have a linear spring rate of 159 pounds up front and 145 pounds in the rear. Both ends feature a closed coil, and use a thin rubber-isolating pad to reduce unwanted noise and vibration.

Solid anti-roll bars are used both fore and aft, measuring 19mm up front and 13mm in the rear. Center bushings feature a standard D-shaped rubber bushing. Drop links are manufactured out of a phenolic material and use rubber bushings with metal inserts.

Subaru uses a standard 5 x 100mm bolt pattern on every Impreza and Legacy, making wheel swaps easy between models. Subaru needed to specify a high 53mm offset to fill the wheel wells with 16-inch diameter, 7-inch wide rims. Early 5-spoke designs, as found on '98 and '99 model years weigh in at 17 pounds, while later 6-spoke designs weigh in half a pound less, at 16.5 pounds.

All 2.5RSs came equipped with V-rated 205/55-16 Bridgestone RE92 tires. Even though they feature a low 160-treadwear rating, RE92s have never received good marks for producing high levels of grip.

A vane-style power steering pump, which changes hydraulic pressure output based on engine speed, controls a rack and pinion featuring a slow 16.5 overall gear ratio. Although never heavy, an RS does require a good deal of wheel shuffling when navigating tight and twisty courses.

Large 10.7-inch diameter ventilated front brake rotors are clamped by twin-piston calipers. Single piston calipers work out back on 10.5-inch diameter solid rotors. Rubber flex hoses supply fluid, while a two-stage power booster supplies the assistance, producing a somewhat mushy feeling pedal. The four-channel anti-lock system features a convenient pull-able fuse for off-road events, as their bumpy nature can often confuse the system into pulling off all braking force.

Out on Track: Stove Stock

Since its introduction, the 2.5RS has been in the middle of a very competitive G Stock class. Obvious heavyweights like the Integra Type R, driven by David Fauth and Kevin McCormick, have dominated national-level events for years. Recently, BMW's excellent handling 3-series, Lexus IS300, and, of course, Subaru's highly touted WRX have raised the power game one more notch.

For 2002, however, G Stock gets blown wide open with SCCA's stock-class reorganization, in which most of the high-powered G Stock machines will be bumped into an entirely new D Stock. Always quick, and well-developed cars from D Stock and E Stock, like the Neon ACR, Sentra SE-R, and CRX Si, move into G Stock, making what will undoubtedly be one of the most diverse stock classes.

The biggest challenge to G Stock 2.5RS competitors will be gaining knowledge on suspension and tire setups. A lot of development will be required to successfully challenge for class victories, given the many different surfaces on which SCCA National Tour and ProSolo events run.

Choosing a correct tire can be difficult, with several suppliers and sizes to choose from. Due to limited clearance in the rear fenders, not all 225/50-16 tires will fit. Kumho's current V700 model will fit without wheel spacers, but will rub through the fender lip molding on cars with stock struts. There is also less than 1/16th inch of clearance between the strut body and underside of the spring perch. It is not known if the new Kumho will have rubbing problems.

With a better strut, helping to control body roll and squat when pulling out of corners, the fender molding will only rub on bumpy courses. High grip surfaces will cause enough side deflection in the tire to rub on the strut, but not enough to cause problems.

Hoosier's 225/50-16 AS03 and RS03 feature a wider section width, and have serious rubbing issues in the back. Hoosier does make a 205/45-16 in the road-race compound, but the 2.5RS's already short gearing is further reduced. While not providing the ultimate grip like the Hoosier and Kumho offerings, Yokohama's A-032R is offered in a stock size 205/55-16, and is a good choice for local events, rain events, or track days.

As is the case with all stock-class cars, struts can dramatically improve the handling characteristics of the RS. Geared more toward the rally crowd, the RS features long suspension travel that is too soft for serious autocross work. Since springs must remain stock, it is up to the struts to help reduce roll, and control body movements during abrupt transitions.

Several struts are available for the RS, ranging from non-adjustable sport struts offered by Subaru, to full-on multi-adjustable rally-grade coilovers, that could be custom built to feature stock spring perches and fixed ride height. The most popular strut is the KYB AGX. It features four adjustments up front, and eight adjustment points in the rear, controlling rebound and compression together. At their lowest settings, they feel very close to stock, with the ability to get significantly stiffer for smooth, high grip surfaces.

Koni manufactures an insert that can be installed in the stock housing, that is proving popular with WRX competitors. More expensive options, such as DMS Gold, Cusco, or Tein coilovers have yet to be tailored for stock class rules.

Aftermarket front anti-roll bars common for the WRX are not readily available to fit the 2.5RS, due to a different front cross-member. Front endlinks, featuring rigid construction and firmer bushings, are offered by Kartboy Kustoms and MRT out of Australia, and help improve initial turn-in and overall feel.

Alignment settings for the RS are course dependent. Front camber should be set to max negative, which comes out to 3/4 degrees. Front toe-out, in the neighborhood of 1/16 to 1/8 inch improves overall front grip, but equal amounts of front toe-in can aid with front end grip when powering out of tight corners. The rear does not have any provision for camber adjustment, but toe is easily adjusted. Rear toe-out, in the neighborhood of 1/8-inch or greater can really help to rotate the car on courses with sweepers.

Numerous brake pads are available for the RS, most popular being PBR Metal Master, EBC Green Stuff, and SPO Motorsports' Carbon pads. Initial bite meaning more for autocross than resistance to fading would be in a road course situation.

No giant horsepower gains can be expected, with the limited amount of modifications allowed in stock class. Amsoil and K&N replacement air filters add a couple of horsepower, especially on the top end, where the RS falls a little flat. Any number of cat-back exhaust systems are available, most featuring either 2.25-inch construction for good mid-range gains, or 2.5-inch construction for better top end. If not providing drastic improvements in lap times, an exhaust does let out that unmistakable Subaru growl, striking fear in fellow competitors.

---continued below---

Last edited by subrew; 10-15-2004 at 05:55 AM..
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Old 10-15-2004, 05:53 AM   #2
subrew
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Default

---continued from above---

Out on Track: Street Tire Fun

The Street Touring S class has become home for most of the 2.5RSs competing in autocrosses around the country. It is not rare to find half or three-quarters of a national-level STS field filled with Subarus. They are a perfect fit for the class-jokingly referred to as "Street Touring Subaru"-where allowable modifications almost read like a Subaru owner's wish list.

Street Touring attracts many sport compact cars-ones that have back seats and are not based directly off a genuine sports car platform, as dictated by the rules. The next most obvious STS rule regards tires. Legal tires must have a treadwear rating of at least 140, and cannot be wider than 225mm. A maximum wheel width of 7.5 inches is also set, with no limitation on wheel diameter.

Up until recently, there were two distinct levels of tires, with maximum performance tires such as the Michelin Pilot Sport, Bridgestone SO-2, and BFGoodrich KD pushing the pocket book at over $200 a piece in Subaru sizes. Older-technology tires, such as the Yokohama AVS-I, Bridgestone RE71, and Dunlop SP8000 have mixed in with new offerings such as the Kumho 712 to offer more reasonably priced alternatives.

The biggest thing to hit STS this past year was the introduction of the Falken Azenis, which features construction similar to a genuine R-compound tire. Stiff sidewalls, shallow 8/32-inch tread depth, and large tread blocks make it a great choice for the serious racer; and a relatively low price tag makes the Azenis an attractive option.

Popular tire sizes for the RS include 205/50-16, stock size 205/55-16, 215/45-16, 205/50-17, and 215/45-17. Each size has its advantages, both in weight and in the effect on overall gearing, as fast courses-such as the South Course at this year's SCCA Solo II National Championship-can often find an RS between second and third. For 2001, both Kumho and BFG offered contingency.

Wheels run the absolute gamut of what is offered in the unique Subaru offset of 53mm. Stock wheels are surprisingly strong and light, and have proven popular, especially the flashy gold wheels from 1998 models. The Tire Rack has begun offering Subaru-specific offerings from Prodrive, and the flourishing Subaru market is attracting new wheel manufacturers to introduce Subaru-specific models. As with all cars though, weight and strength are primary concerns.

Suspension modifications in STS are almost unlimited, when it comes to replacing struts, springs, and bars. Like stock class, struts can be found as close as the Subaru dealer, in the form of genuine pink STi V5 units, or require shipment on the slow boat from Japan or Australia for custom-built, high-dollar units.

Again, KYB's AGX struts have proven popular, because of their adjustable nature and attractive price. They work quite well with most aftermarket springs, featuring reduced ride heights down to 1.5 inches. Subaru's own V5 springs, as well as offerings from Eibach, H&R, and 5Zigen, provide a good compromise for daily-driven RSes on a budget.

If ride height adjustment is desired, Ground Control offers an attractively-priced coilover kit that can be mounted on existing AGX struts. A step up in performance, quality, and price, are DMS's Gold struts, and other coilover setups from Cusco, Tein, and Syms, that offer increased levels of adjustment. Subaru offers stiffer STi strut top mounts, as used in the WRX. These help to eliminate any squish in the mount, and have shown to reduce bouncing caused by stiffer setups running the stock rubber strut tops.

One of the biggest improvements that can be made to an RS, is the addition of a larger rear anti-roll bar. Subaru offers both 18 and 20mm factory units, as used on overseas WRX models. Combined with stiffened end links, this combination can provide a very noticeable improvement for minimal expense. Adjustable rear bars from Whiteline and SPO Motorsports feature three-way adjustment, allowing much better control of vehicle balance.

Strut tower bars are offered for both front and rear towers. Quite a few different designs exist, with offerings from Syms, SPO Motorsports, and Primitive Enterprises proving most popular. Subaru even offers two models in its accessory catalog.

Greater than stock camber adjustment is important on an RS running street tires. Simple kits for the lower strut mounting bolt can give up to 1.5 degree negative camber, but need to be checked for tightness, as they have shown to loosen with use. Full-on camber plates, as offered by Cusco, give several degrees of movement, and have proven to be user friendly and well built. Alignment settings are similar to stock-class cars, but may need to be tailored to work with street tires. Brian Priebe, former STS National Champion, recommends zero front toe, with a bit of rear toe-out to help the car get around the corners.

Power boosters in STS are limited to bolt-ons such as intake, exhaust, and fuel computers. Certain components, like throttle bodies and catalytic converts, must remain stock. This essentially places restrictions on the airflow, so that illegal internal engine work won't provide much benefit.

Quite a few intakes are offered for the RS, for both MAF and MAP systems. The simplest method uses an Amsoil or K&N replacement filter, and the replacement of the stock air muffler with a fabricated section of pipe drawing air from the passenger fender. This system retains the stock Subaru air box and mounting, helping to eliminate vibration problems with the early MAF sensors.

Full intake systems are offered that replace the complete airbox with a section of pipe, and mount an exposed cone style filter. Recent designs incorporate heat shielding, to block heat coming off the engine. On MAF-equipped cars, full intakes have proven to lean the engine out considerably at high rpm, requiring the use of a piggyback fuel computer, such as the Apex-I unit, to adjust the air/fuel mixture. MAP-equipped cars tend to run lean, and can benefit from a fuel computer as well.

Catalytic converters must remain stock; however, STS rules allow for aftermarket headers and exhaust systems in their stock locations. The most popular header design is offered by Borla, and has gone through several design variations to improve fit and performance. When combined with a good exhaust, such as the Borla stainless unit, or offerings from Syms and Stromung, this package can add about 10hp, with a good broad increase through the power band.

Replacement of crankshaft dampers is not allowed in STS, but pulleys can be replaced. Luckily for Subaru owners, this component is called a pulley in the Subaru service manuals, allowing the use of Unorthodox underdrive pulleys, freeing up a bit more power.

Well outside the rules of STS, but perhaps appropriate for those seeking out the ultimate modded RS, are reworked camshafts and cylinder heads from Cobb Tuning. The Texas-based company offers two different specs of cams: "mild," for the street, and "hot ," for turbo-equipped cars. Cobb's reworked cylinder heads come in two different stages, depending on the overall state of engine tuning desired.

Last but not least, several extensive turbo kits are offered for the RS, the most prominent being the one developed by Vishnu Performance Systems, which features all the turbo hardware and an Electromotive Tec-II engine management system required to make it all run properly. Vishnu's system has proven to produce in excess of 300hp, making for an absolute rocket ship.

But back to Street Touring: There has been talk of bumping the 2.5RS out of STS, and into a possible new STS2 class for 2002, possibly opening the door for some of these modifications not currently allowed by the ever-changing rules. This movement may have been stemmed, however, by the fact that all the 2.5RSs were sent packing by a little Civic Si hatchback at the Solo II Nationals. We'll just have to wait and see how the rules play out, and how Subaru's factory hot rod will fare next year.

Out on Track: Rallycross Action

The bumpy, mud-slingin' nature of local rallycross events can require added modifications, for reasons of safety, protection, and competitiveness. Just about every club makes some distinction between basically stock or highly modded cars when it comes to classification, so it is always good to check with the local club.

Regardless of the class, there are a few things that should be considered for rallycross events. Underbody protection can be vital, and companies like Primitive Enterprises, with years of Pro Rally experience, build genuine rally-grade skidplates and differential protectors. These plates keep road debris, or tree stumps, from damaging vital engine or drivetrain components.

For classes allowing open tread tires, many competitors have found that knobby snow tires offer good traction, and can be used during winter months. The ultimate rallycross tire however can be found out behind the back of a Pro Rally team's service van. Top rally teams often sell partially used rally tires for $25 to $50 each, depending on condition and size.

The most popular used rally tire choices are the Michelin and Silverstone brands, in 15/64-15 size. Snow tires can easily be found in 195/65-15 or 205/60-15 size, and, of course, can be found in sizes to fit the stock 16-inch wheels.

Since most snow and rally tires are offered in 15-inch diameters, many competitors use either factory Subaru steel wheels or aluminum rims from earlier-model Imprezas and Legacys. Subaru wheels are known to be strong, and are guaranteed to fit. Some off-brand steel wheels haven't held up to the abuse a rallycross can inflict.

What to Expect in 2002


One thing is certain: Subaru's good relationship with the SCCA and continued support of amateur racers through contingency programs will ensure a good turnout of 2.5RS Imprezas. While a bit overshadowed by the hot new WRX in 2001, an RS will have a better autocross playground in the shape of a revised a G Stock.

Considered to be one of the heavyweights in a class no doubt filled with sprightly Neons and CRXs, the RS will get a chance to show its muscle and gripping power. The Impreza should do likewise in STS, as increased development and practice for top drivers will give the RS "overdog" status for yet another year-whether it deserves it or not.

Big Brother: Legacy 2.5GT (sidebar)

If the 2.5RS feels a bit too racy, and you would rather have leather under your bum and soothing wood grain to look at during your commute, you might consider a Legacy 2.5GT. The big brother to the RS, the 2.5GT is based on the larger Legacy platform, and was first offered in 1996.

Originally outfitted with a 155hp DOHC 2.5 liter, upgrades in 1997 saw that figure bumped to 165hp, with a corresponding increase in mid-range torque. Weighing in a couple hundred pounds more than the RS at 3,050 pounds, the GT still provides crisp handling, thanks to upgraded suspension bits compared with a standard Legacy.

Outside, a 2.5GT is distinguished by a subtle hood scoop and front air dam, featuring small rectangular fog lights. A rear wing, looking like a stubby RS wing, sits atop the rear deck. Attractive cross-spoke wheels measuring 16x6.5 inches are wrapped in the same 205/55-16 Bridgestone RE92s found on the RS, except for slightly higher treadwear rating, and H speed rating.

In 1998, a versatile GT wagon joined the lineup, featuring a large back hatch, opening up to a total of 49 cubic feet with rear seats lowered. This proved a good alternative to the increasingly popular Outback wagon for the driver who desired more road prowess.

Under all this flash lies the same DOHC engine that was pulled from the shelf for the first 1998 2.5RSs. This engine was used throughout the production of second generation 2.5GTs, as Subaru never saw fit to change over to the Phase II SOHC engine that was installed in the 1999 and on 2.5RS and Forester models. The new engine did find a home in the completely new 2000 model Legacy line.

Compared to a standard Legacy, the GT sits 0.8 inches lower on stiffer springs, with firmer struts fore and aft. The same brakes, steering system, and basic suspension geometry are all shared with the RS.

With so many components shared between models, a 2.5GT owner need only peruse the catalogs of the many Subaru performance shops to find hot rod parts. With a few minor modifications, items like adjustable struts, sport springs, and brake pads, to 250-plus horsepower full turbo kits can be installed on a GT. If so equipped, a 2.5GT owner will surely have one of the most unique rides at any Subaru gathering, and if properly sorted, can even put its little brother to shame on the track.

Brian "Street Tire" Priebe (sidebar)

It's hard to image that the best known "Street Touring Subaru" driver started his racing career in an Acura Integra. But, declares Brian Priebe, "I learned the most from driving the front-wheel-drive cars." After a spell in the Integra, Brian jumped into a BSP Datsun 240Z, then moved into several E and D Stock Neons, where the "competition helped me polish my skills," he says.

Those polished skills gave Brian the confidence to move into the very competitive field of C Stock with a Toyota MR2. Again, Brian had the opportunity to put the theories he had learned during previous years into practice. "The MR2 helped me, because I could really transform the car from the beginning, making it do what I wanted," he says.

The toughest thing about taking on the new Street Touring class, which Brian did in 2000, was getting used to how street tires perform, and how changes to the alignment, shocks, various chassis braces, and air pressures can affect them. Since STS allows for quite a few modifications, choosing the right components and making them work together can be a challenge.

Starting with the suspension, Brian has used both KYB AGXs and Koni inserts, favoring the Konis for their customizable nature. Eibach Pro-Kit springs lower the car about 1 inch, while Cusco front camber plates allow up him to set camber at 2 to 2.5 degrees negative. A Whiteline rear anti-roll bar is adjustable from 18 to 22mm.

Alignment is very dependent on course design, Brian states, but he feels zero front toe gives the best grip when the car is loaded in sweepers, while rear toe can change from 1/8-inch toe-in to a dramatic 1/2-inch toe-out. "Rear toe-out really helps drive the car around the turns," he says. This is important since all-wheel-drive cars naturally understeer in sweepers.

To ramp up the power, Priebe's Impreza is fitted with an Unorthodox underdrive pulley, Borla header, SPT/Brospeed exhaust, Weapon R intake with K&N filter, and APEX fuel controller. Brian is very adamant about the performance of his Kumho 712 tires: "You can really drive on them hard since they are more forgiving on the edge." Giovanna G-Racing wheels, in 17x7 inch size, feature a shallow 42mm offset that barely fit the car.

After capturing the SCCA STS National Championship in 2000, Brian was considered the front runner for 2001, but the unfortunate circumstances that surrounded the event didn't allow him to compete. His car recently sold, Brian plans on switching classes next year. He anticipates running the Cobb Tuning-prepared WRX in Street Mod, or an MR2 Spyder in C Stock. One thing is for sure: Brian will be a top contender no matter the car or class.

Rally Richard: Pat Richard (sidebar)

Rocket Rally Racing's Pat Richard (pronounced "re-shard") quickly became the hero of 2.5RS drivers by winning SCCA Pro and Canadian rallies, with his nearly stock 2.5RS. From Whistler, British Columbia, Pat spent his early years skiing and snowboarding, no doubt learning much about proper lines and late apexes. In fact, he didn't start racing until May 1999, when he jumped directly into the Pro Rally scene.

Pushing his daily driver into action, Pat went about modifying his car to fit SCCA's Production GT class. Pat's RS went through several stages of modifications over a two-year period, from stock struts and Outback Sport springs to the incredible 50mm "Giant" struts that now reside under the car. By the end of the 2000 season, Pat's RS was perhaps the best developed in the series.

Those Drummond Motor Sports Giant 50mm struts provide much needed durability, given Pat's legendary aggressive driving style. Twenty-four adjustment points for both rebound and compression give enough flexibility to tackle snow-covered roads or fast, sweeping tarmac stages.

Primitive Enterprises front and rear strut tower bars feature an eccentric pre-load cam for increased rigidity, keeping chassis flexing to a minimum. A 4-puck Primitive Enterprises copper-button clutch transmits drive through a stock 5-speed transmission. Both front and center differentials remain stock, but the rear diff houses a 100-percent lockable KAZZ limited slip.

As required by Production GT rules, brake rotors and calipers remain stock; but Porterfield RS4 carbon metallic pads are substituted to withstand the heat generated through left-foot braking. Extensive underbody protection is provided by Primitive Enterprises' front skidplate and rear differential protector.

Raceline RL-7 wheels, 15-inches in diameter, are wrapped with either Michelin FB81 or Silverstone S525 tires in size15/64-15. For snow events, 195/65-15 Yokohama WR26 tires are used, unless these is a solid ice base, in which case same-sized Nokian Hakkapelita Qs are put to use. Tarmac stages are tackled with Yokohama A520 tires, measuring 205/40-17.

No matter how top notch the equipment may be, though, any successful car-and-driver combination must have the support of a dedicated team. That support comes from Rocket Rally Racing's two co-drivers, Ian McCurdy and Ben Bradley, and crew chief Dave Clark, owner of Dave Clark Motorsports located in Seattle, Wash. Nathalie Richard, team boss, keeps everyone on task and in winning form.

And winning form is what Rocket Rally Racing has come to expect, after winning the 2000 Production GT driver and co-driver titles. The team's efforts also helped Subaru clinch the manufacturer's championship for both Subaru of Canada and Subaru of America.

This past year, Pat decided to retire his RS Impreza in favor of a beautiful new WRX. One certainly can't blame Pat for changing rides, since the increased power and greater chassis strength of the WRX will be required to keep his championship-winning form alive.

---end---
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Old 10-15-2004, 06:22 AM   #3
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Nice article.
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Old 10-15-2004, 06:39 AM   #4
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I vote sticky. Well done.
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Old 10-15-2004, 07:33 PM   #5
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mind if I add this to my FAQ thread?
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Old 10-15-2004, 08:38 PM   #6
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that would be fine. I also posted a similar article in the rally forum, that discusses setting up Subies for rally.

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Old 10-16-2004, 05:24 PM   #7
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Nice article! Always a pleasure to read about the history of my Sube.
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Old 10-18-2004, 11:55 AM   #8
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great article! really loved the history!
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Old 10-18-2004, 12:49 PM   #9
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Outstanding Article!! what an awesome read!
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Old 10-18-2004, 02:01 PM   #10
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Very nice write up. You should post the pics that came in the magazine
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