GC8 Great: Insane, Street-Legal 1998 Subaru Impreza 2.5 RS Coupe

This independent, Canadian-built 1998 Subaru Impreza sporting a JDM WRX STI swap is perhaps the greatest street-legal GC8 on the planet, combining time attack functionality with an aggressive looks. Prove us wrong.

Story by David Pratte. Photos by Amee Reehal.

When you think of the Subaru Impreza, chances are the first images that come to mind are the awesome WRC machines piloted by rally icons like Colin McRae and Richard Burns. Or if you’re more into time attack than rally, perhaps its images of fender-flared and big-winged monsters like GST’s, Top Speed’s, or Zen Performance’s Unlimited class Imprezas that call your screen saver home.

First, why modify a classic 1998 Subaru Impreza?

For Dave Mann of Kelowna, British Columbia, his influences come from the dirt and the pavement. “It started for me out of a love for WRC. I had never really been into cars for the majority of my teen years. Instead, I raced downhill mountain bikes at a high level.

1998 Subaru Impreza 2.5 RS Coupe
1998 Subaru Impreza 2.5 RS Coupe. Photo: Amee Reehal

Naturally, rally was something I took a liking to, as it’s very similar to downhill racing in some ways [loose surface and racing against the clock]. This, along with the fact that we were constantly shuttling on gravel roads in the mountains, drew me to Subaru.”

Subaru dealer informed him that they had a Rally Blue Pearl GC8 with a blown motor on the lot. He immediately sold his WRX and picked up the ’98 rolling chassis

In 2002, when Subaru brought the WRX to the North American market, Dave knew he had to have one. But because he was barely old enough to drive at the time (he’s now 23 years old and about to graduate from college with a degree in Finance), it wasn’t until 2005 that he sold his ’91 Toyota pickup truck and found a used ’02 WRX that fit his budget.

1998 Subaru Impreza 2.5 RS Coupe
1998 Subaru Impreza 2.5 RS Coupe. Photo: Amee Reehal

“That’s when I started to get into the modding scene. It started off light, but as most people know, the obsession grew fast. Within a year I had the car set up with all the basics, plus an upgraded turbo and fuel system, having done all the work myself. It was a great learning process, but I was hooked and wanted to do something bigger and better. I wanted to do a classic (’98-01) body style with a complete swap.”

Dave’s stars aligned when his local Subaru dealer informed him that they had a Rally Blue Pearl GC8 with a blown motor on the lot. He immediately sold his WRX picked up the ’98 rolling chassis and began researching the challenging JDM STI engine and transmission swap.

Performance: JDM WRX STI engine swap with an Ultimate Racing GT35R turbo kit

1998 Subaru Impreza 2.5 RS Coupe engine
1998 Subaru Impreza 2.5 RS Coupe. Photo: Amee Reehal

“After many phone calls, I finally sourced my swap from Andre at SwapShopRacing.ca out of Blainville, Quebec. Once the complete JDM Version 7 WRX STI engine and Spec-C 6-speed transmission arrived, my friends and I completed the install over the winter months, and by the summer of 2007 the car was on the road.”

Dave continues, “At this point, it was basically stock with the exception of the new engine and transmission.”

So rather than building his GC8 to slide sideways through the dirt, his objective was to turn his Impreza into a low-budget time attack special and aggressive street car

It was around this time that Dave developed an interest in time attack. So rather than building his GC8 to slide sideways through the dirt, his objective was to turn his Impreza into a low-budget time attack special and aggressive street car.

Custom-built eight-point roll cage

1998 Subaru Impreza 2.5 RS Coupe custom roll cage
1998 Subaru Impreza 2.5 RS Coupe. Photo: Amee Reehal

This meant gutting the interior and having Alsek Industries fabricate a CARS-spec (Canadian Association of Rallysport) eight-point roll cage, as well as developing some functional aerodynamic aids to go along with the usual power-adders and suspension modifications

“One thing that is really important to me about this car is that it is 95 percent self-built. I have not had a shop do anything to the car except for the ECU tuning and cage work. Everything else I did myself, with the help of my friends,” Dave proudly explains. 

Increased power courtesy of a turbo kit, ECU, and (much, much) more

Under the hood there’s been no shortage of wrench-spinning by Dave and his crew, the ’01 v7 engine having been treated to an Ultimate Racing GT35R turbo kit including an up-pipe and a 3-inch racing downpipe.

1998 Subaru Impreza 2.5 RS Coupe turbo
1998 Subaru Impreza 2.5 RS Coupe. Photo: Amee Reehal

Controlled by an Autronic SM4 stand-alone ECU, power is sent to all four wheels through Suretrac front and rear LSDs and a 20kg viscous centre differential. And there’s no shortage of power to be distributed, the current 94-octane pump gas tune being good for 470 bhp at 1.4 bar of boost pressure.

If Impreza hatchbacks are more your thing, check out our modified 2008 Subaru STI 5-door feature here, packing power, style, and dark looks including a full Stage 2 upgrade putting down almost 300 horsepower. 

Impreza Coupe’s custom styling modifications

One of the more distinctive modifications to Dave’s Impreza is the Limit Factory rear diffuser, a custom one-off item built by this small local fabrication shop. Installing it meant cutting a big hole in the trunk floor as well as the rear bumper cover.

1998 Subaru Impreza 2.5 RS Coupe
1998 Subaru Impreza 2.5 RS Coupe. Photo: Amee Reehal

But Dave has never been one to shy away from adventurous mods like this, which not only look wild but more importantly should significantly improve rear downforce.

The Do-Luck side skirts are also both functional and quite rare (especially on a GC8), complemented nicely by the Seibon carbon-fiber hood and front lip. The rest of the exterior is all JDM Version 6, from the STI foglight covers to the front grille and rear spoiler.

1998 Subaru Impreza 2.5 RS Coupe interior
1998 Subaru Impreza 2.5 RS Coupe. Photo: Amee Reehal

Impreza WRX’s wheels, suspension, and footwork

Just as much as the wild rear diffuser and unique aero package, it’s the wheel offset and stance of Dave’s Impreza that sets it apart from the crowd. It’s not every day you see a set of JUN Nissan S13 fender flares on a Subaru, but that’s exactly what Dave chose to create the super-flush look on his GC8, along with Rota SVN-R 18×10-inch +30 wheels spaced out to a +5 offset up front and +1 out back.

1998 Subaru Impreza 2.5 RS Coupe wheels
1998 Subaru Impreza 2.5 RS Coupe. Photo: Amee Reehal

It’s not every day you see a set of JUN Nissan S13 fender flares on a Subaru, but that’s exactly what Dave chose to create the super-flush look on his GC8

Rolling on 265/35-18 Bridgestone RE-11s, ride height was set with Racecomp Engineering Tarmac II double-adjustable coilovers. The rest of the running gear is straight off a ’01 Version 7 WRX STI-from the axles to the hubs, rotors, and calipers, along with Cusco camber plates and a Whiteline 24mm rear antisway bar.

Takeaway: home-built Subaru with future plans

Having home-built this stunning Subaru with a style all its own, Dave Mann has no plans to stop developing his GC8. “My future plans include an upgraded fuel system with a surge tank, a built 2.5-liter engine tuned for high boost with an Aquamist water injection system, and an Accusump wet system.

He adds, “I also plan to do some more custom aero work.” With a seven-page thread on NASIOC.com featuring nothing but declarations of love and admiration for Dave’s Impreza, there’s no shortage of fans (us included) who’ll be watching as he continues to push the boundaries of function and form on this truly great GC8.

1998 Subaru Impreza 2.5 RS Coupe

Quick GC8 history and Subaru’s credentials as a high-performance brand

Subaru owes much of its current popularity in the tuner/high-performance market to the success of its World Rally Championship program. In fact, the STI division was created by Subaru in the late ’80s to spearhead its WRC effort.

With WRC manufacturer’s championships claimed in 19=95, 1996, and 1997 and a driver’s championship in 1995 by the late-great Colin McRae, it was on the dirt in a GC8 (built in large part by Prodrive) that Subaru established its credentials as a high-performance brand and earned the company a loyal following in the process.

1998 Subaru Impreza 2.5 RS Coupe rear diffuser
1998 Subaru Impreza 2.5 RS Coupe. Photo: Amee Reehal

GC8 chassis continues to dominate the time attack

Two Impreza generations later, the GC8 chassis continues to dominate time-attack beasts campaigned by the likes of GST Motorsports, Top Speed, Roger Clark Racing, and Zen Motorsports.

Due to its relatively low mass (compared to GD and GR Imprezas) and expert tuning, the GST GC8 has won the Modified Tuner Shootout two years in a row as well as being a top runner in the highly competitive Unlimited AWD time attack division.

Below, are full specs and pictures.

Specs for Dave Mann’s Tuned 1998 Subaru Impreza 2.5 RS Coupe

Engine2.0-liter EJ20 2001 JDM Version 7 WRX STI
Engine UpgradesUltimate Racing GT3582R (0.82a/r) turbocharger, racing up-pipe, and 3″ downpipe; AUS spec turbo blanket, HKS turbo heat shield, TiAL 44mm wastegate, TurboXS FMIC, custom Regan Ritchie intercooler piping, modified/reversed intake manifold, Invidia G200 3″ after-cat exhaust, Deatschwerks 850cc fuel injectors, Walbro 255-lph fuel pump, Mishimoto radiator and slim fans; Element Tuning race air/oil seperator, Mocal race oil cooler, rear-mounted Braille 6-lb carbon-fiber battery
Engine ManagementAutronic SM4 stand-alone ECU w/ antilag, A’PEXi AVC-R electronic boost controller
SuspensionComplete ’01 Version 7 WRX STI suspension conversion (control arms, knuckles, hubs, subframes), Racecomp Engineering Tarmac II double-adjustable coilovers, Cusco adjustable camber plates (f/r), Whiteline 24mm rear sway bar
Wheels, Tires, BrakesRota 18×10″ SVN-R +30 wheels (25mm spacers front, 29mm spacers rear), Bridgestone 265/35R18 Potenza RE11 tires, Rays extended lug nuts, complete ’01 Version 7 WRX STI brake conversion (hubs, rotors and calipers), Hawk HP+ brake pads, Goodridge SS brake lines
Drivetrain2001 JDM Version 7 WRX STI Spec-C 6-speed transmission, Suretrac LSDs (f/r), 20kg viscous center differential
InteriorAlsek Industries CARS-spec 8-point rollcage, Nardi Rallysport 330mm suede steering wheel, Momo quick release hub, Racetech RT-Pro 5 cam-lock harness, Sparco Circuit race seat, JDM WRX STI pedal set, Cobb Tuning double-adjustable short shifter, WC Lathewerks custom shift knob, custom carbon-fiber center switch panel, A’PEXi AVC-R monitor, Defi bf-series controller w/ boost, oil pressure, EGT, oil temp and water temp gauges; Aquamist dds3 flow gauge, ’05 WRX STI gauge cluster conversion
ExteriorSeibon carbon-fiber hood and front lip; KLight 6,000K HID headlights, PIAA Ion Yellow corner lights, JDM Version 6 STI foglight covers, front grille, and rear spoiler; JUN S13 fender flares, Do-Luck side skirts, Limit Factory custom rear diffuser
Special ThanksLimit Factory, Drift Union, Benvoulin Hot Rod Shop, Rocket Rally and everyone who helped out with the build.

Interior and exterior Subaru GC8 pictures

Photos: Amee Reehal

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Author:
Amee Reehal
Amee Reehalhttps://www.ameereehal.com/
Shooting cars and bikes professionally since film was a thing, for over 20 years, Amee has collaborated with the major automakers and agencies, and his work has been published in various global outlets including MotorTrend, GlobeDrive, SuperStreet, Chicago Tribune, PerformanceBMW, and others. He’s the founder and managing editor of TractionLife.com, focusing on digital marketing & SEO for the past ten years (backed by a marketing degree, go figure). Find him travelling, spending time with his kids and family. Or golfing, poorly.