Honda · 2002–2005 · track setup

Civic Si EP3

The EP3 brought the K20 engine to the Civic Si, in a UK-built three-door hatch with a dash-mounted shifter. It moved to MacPherson struts up front, and the steering geometry is its main weakness once lowered: bump steer and a low roll centre make it wander and squirm. Fix the geometry, give it camber and better brakes, and it is a cheap, durable momentum car that shares much of its chassis and parts with the RSX.
Engine
2.0 L DOHC i-VTEC four (K20A3), 5-speed manual, open differential
Power
160 hp and 132 lb-ft
Weight
≈2,744–2,782 lb (hatchback, manual)
Layout
Front-engine
Drive
FWD
Performance planner ↓

These are starting points gathered from the sources listed at the bottom, not a guarantee. Cars, tires and parts vary: have a reputable alignment shop set your car, check factory specs for road use, and change one thing at a time.

01On track

Strengths
  • +Torquey, durable K20 engine with a wide powerband
  • +Light hatch with a short, quick dash shifter
  • +Shares chassis parts and much of its aftermarket with the RSX (DC5)
  • +Cheap to buy and run
Watch out for
  • −Steering geometry causes bump steer, worse once lowered
  • −Open differential and no factory LSD option
  • −Small 10.3-inch front rotors
  • −Limited front camber adjustment on the stock strut

02Alignment

Where to start the alignment.

Alignment · starting points
VIEWED FROM BEHIND · CAMBER EXAGGERATED ×3-3.0°FRONT L-3.0°FRONT R-1.7°REAR L-1.7°REAR R
FrontRear
Camber≈-3.0°≈-1.7°
Toe≈1/8" out0
Caster≈2.5° (more with offset lower-arm bushings)—

The alignment MotoIQ ran on its project EP3 after the bump-steer and roll-centre kits; the author called it aggressive but streetable. On this rear suspension one adjustment moves both camber and toe, so allow extra time on the alignment rack.

Sources [4,5]

03Tires & brakes

Tires and brakes

  • 200TW endurance
    • Hoosier Track Attack Pro
    • Yokohama Advan A052
    Factory 195/60R15 (2002–03) and 205/55R16 (2004–05); track builds commonly go to wider 16" or 17" sizes

    Both are 200-treadwear track-oriented tires. Check size availability and wheel clearance for your offset.

    Sources [2,3,12,13]
  • R-compound / slick
    • Hoosier TrackAttack Race R8 (replaces the R7)
    Check the Hoosier catalogue for 15"–17" sizes

    Only once the geometry and brakes are sorted; R-compounds add load the stock brakes and bushings were not built for.

    Sources [14]
Brake pads

A track compound in the correct Si fitment. Retailer guidance for the EP3 Type R lists Ferodo DS2500 (dual-duty, about 0–500°C) and PBS ProTrack (about 0–700°C) as track pads; the Type R front caliper differs from the Si's, so confirm Si fitment.

Brake fluid

Motul RBF 600 (312°C dry) or RBF 660 (328°C dry), or equivalent high-boiling DOT 4.

Braided lines firm the pedal. A big brake kit is the stage-two fix once pad and fluid are not enough. [6,10,11]

04Known issues on track

Fix these before they find you.

  • Bump steer and roll centre

    MotoIQ explains that the steering rack sits high on the firewall with a short rack and long tie rods, so the wheels toe in and out as the suspension moves. Lowering drops the roll centre and makes it worse. Their project car skittered in bumpy corners until it got bump-steer tie rod ends and roll-centre ball joints, which nearly eliminated the feeling. Their later comments warn that the inverted tie rods can over-correct, so do not pair them with a rack riser. [4,5]

  • Brakes: small rotors and fade

    Honda lists 10.3-inch front and 10.2-inch rear discs. MotoIQ's project replaced them with 12.2-inch rotors and six-piston calipers for more pad area and fade resistance. On a stock car, start with a track pad, high-boiling fluid and braided lines (rubber lines make the pedal soft when hot), and treat brake fade as the first limit you will hit. [2,6,10]

  • Open differential

    Hybrid Racing's transmission guide lists the EP3 Si gearbox without a limited-slip differential, so expect inside-wheel spin out of slow corners. An aftermarket LSD is a later, bigger job. [9]

  • Gearbox and mounts on hard-used cars

    UK buying guides for the closely related EP3 Type R (summarised by JDM Buy Sell) say the synchros take a pounding, that timing chains should be checked on high-mileage cars, and that engine and gearbox mounts can fail on cars that were tracked hard. Check for crunchy shifts, a cold-start chain rattle and excess engine movement before buying. (Type R guidance, applied to the Si.) [15]

05Modification roadmap

In the order that pays off.

  1. 0
    Safety & reliability first

    Safety and reliability first

    • Track pads, high-boiling fluid and braided linesThe small stock brakes fade first.
    • Check mounts, chain and gearbox on a used carHard-used EP3s wear mounts and synchros.
    • Seats and harnesses only with proper roll protectionNever fit harnesses without a roll bar or cage.
  2. 1
    Tires & alignment

    Tires and alignment

    • 200TW tiresThe biggest grip gain for the money.
    • Front camber bolts and a rear camber kitGets you to -1.5° to -2.0° front for dual duty.
  3. 2
    Suspension & brakes

    Geometry and suspension

    • Bump-steer tie rod ends and roll-centre ball jointsFixes the wander and squirm, especially on a lowered car.
    • Coilovers at a modest dropBody control without making the geometry worse.
    • Bigger front brakesMore pad area and rotor mass for long sessions.
  4. 3
    Power & aero

    Power last

    • Limited-slip differential, then engine workTraction out of slow corners matters more than power on an open-diff car.

06Performance planner

What each upgrade is worth on this car.

Pick upgrades and see the estimated lap-time change on a reference circuit, how much margin your brakes and engine have late in a session, and which changes buy durability rather than speed.

Performance planner · Civic Si EP3Model estimate
Tires
Brake pads
Brake fluid
Brake cooling
Brakes
Alignment
Suspension
Differential
Weight
Power
Cooling
Oil system
Aero
1:55.83stock 1:55.83−0.0%

Reference circuit (fictional, 3.5 km). Late lap includes brake fade and heat derating once the system runs out of margin.

T1T2T3T4T5T6T7T8SPEED · your plan vs stock · top 107 mph
Brake fade marginFades
Engine heat marginHolds
Oil starvation riskLow
Tire life (relative)100%
Sensitivity · each upgrade alone vs stock (late lap)
  • R-compound tires−5.60%load ↑
  • 200TW endurance tires−2.59%load ↑
  • Race pads−1.33%durability ↑
  • Big brake kit−1.30%durability ↑
  • Street/track pads−1.19%durability ↑
  • High-temp fluid−0.87%durability ↑
  • Brake cooling ducts−0.87%durability ↑
  • Track alignment−0.82%
  • Coilovers + sway bars−0.69%
  • Splitter + wing−0.60%
  • Lighter wheels + seat−0.30%
  • Limited-slip differential−0.12%
  • Oil cooler + radiator±0durability ↑
  • Oil system (baffles / accumulator)±0
  • Intake, exhaust, tune±0load ↑
This car’s roadmap below starts with: Track pads, high-boiling fluid and braided lines · Check mounts, chain and gearbox on a used car · Seats and harnesses only with proper roll protection · 200TW tires

Estimates from a simplified point-mass lap simulation of Civic Si EP3 (2,745 lb, 160 hp) on a fictional circuit, with generic effects for each upgrade category. Good for comparing options on the same car, not for predicting your lap time. Real results depend on the driver, the exact parts, the track and the conditions. Durability starts lower on this car because of its known issues: brake fade.

Free printable setup sheet →

Sources

Last reviewed 2026-10-18. Summaries are TRACK’s own wording; follow the links for the original detail. Product and brand names belong to their owners.

  1. [1]Honda Civic Si Timeline and MilestonesHonda (hondanews.com) · accessed 2026-10
  2. [2]2004 Honda Civic Si SpecificationsHonda (hondanews.com) · accessed 2026-10
  3. [3]2002 Honda Civic Si IntroductionHonda (hondanews.com) · accessed 2026-10
  4. [4]Project EP3 Civic Si: Fixing EP3 Bumpsteer with Hardrace (page 6, alignment)MotoIQ · accessed 2026-10
  5. [5]Project EP3 Civic Si: Fixing EP3 Bumpsteer with HardraceMotoIQ · accessed 2026-10
  6. [6]Project EP3 Civic Si, Improving the Brakes with Fastbrakes, Stoptech and WilwoodMotoIQ · accessed 2026-10
  7. [7]Eibach Camber Bolts for 02-04 RSX / 02-11 Civic Si / 09-13 FitHybrid Racing (vendor) · accessed 2026-10
  8. [8]Megan Racing Rear Camber Kit – 01-05 Civic / 02-05 Civic Si EP3 / 02-06 RSX DC5Prestige Autolab (vendor) · accessed 2026-10
  9. [9]K-Series Transmission GuideHybrid Racing · accessed 2026-10
  10. [10]6 Best Honda Civic Type R EP3 Braking UpgradesExo Racing (retailer) · accessed 2026-10
  11. [11]Motul RBF 600 / 660 Racing DOT 4 Brake FluidHybrid Racing (vendor) · accessed 2026-10
  12. [12]Track Attack ProHoosier Racing Tire · accessed 2026-10
  13. [13]ADVAN A052Yokohama Tire · accessed 2026-10
  14. [14]Circuit Racing tires (TrackAttack Race A8 / R8, replacing A7 / R7)Hoosier Racing Tire · accessed 2026-10
  15. [15]Honda Civic EP3 buyer's guide (summarising Autocar and PistonHeads)JDM Buy Sell · accessed 2026-10
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