A documentation-first build log for my FG2 K20Z3. Every mod researched, priced, and installed in the open.
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| Spec | Value |
|---|---|
| Chassis | FG2 (8th Gen Coupe) |
| Engine | K20Z3 — 2.0L i-VTEC, 197 HP / 139 lb-ft (stock) |
| Transmission | 6-speed manual |
| Color | Blue |
| Mileage | ~170,000 miles |
Every modification gets its own folder with research notes, part numbers, real prices paid, and install references. It's also a planning tool — a chronological mod order, a 170k-mile maintenance plan, and a small Python script that compiles the whole thing into printable PDFs. Cars are a hobby I picked up in mid-2025, so this repo doubles as my way of learning the platform and keeping myself honest about scope and budget.
Daily-drivable with a sport mode toggle. Quiet when I need it, loud when I want it. I'm building a full bolt-on NA K20Z3 targeting 220-240 WHP on pump gas, 230-250 WHP on E85 — headers, intake manifold, throttle body, exhaust, pulleys, flex fuel, and a Hondata tune to tie it all together. The exhaust is a DIY valved 3" setup with a QTP cutout, so I can swap between a quiet daily tune and an aggressive straight-piped sport tune. Flex fuel with real-time ethanol sensing lets me run pump gas or E85 without re-tuning. And eventually I'm putting a LattePanda mini PC in the car for permanent Hondata management and exhaust valve control.
| # | Mod | Part | Actual Cost | Status |
|---|---|---|---|---|
| 1 | Clutch & Flywheel | Exedy Stage 1 Organic (08806) + Exedy Lightweight Flywheel (HF02) | $960.43* | Installed |
| 2 | Cold Air Intake | K&N Typhoon 69-1014TS | $504.17 | Installed |
| 3 | Short Shifter + Bushings | Acuity 3-Way Adjustable + Trans-Side Bushings | $622.20 | Installed |
| 4 | Tires | Continental ExtremeContact DWS06 Plus 215/45ZR17 91W XL | $715.00 | Installed |
*$960.43 includes clutch, flywheel, and strut bar bundled together (incl. tax/shipping)
| # | Mod | Part | Actual Cost | Status | Notes |
|---|---|---|---|---|---|
| 5 | Engine Mounts | Hybrid Racing 70A | $657.15 | Awaiting install | |
| 6 | Brakes | Hawk HPS Pads + R1 Concepts Slotted Rotors | $532.14 | Awaiting install | Full 4-corner upgrade |
| 7 | Strut Bar | Megan Racing Race Spec Front Upper (Polished) | (in #1) | Blocked | Clearance issue — need to diagnose |
| 8 | Hondata FlashPro | Hondata FlashPro | $859.59 | Awaiting first flash | ECU tuning, datalogging, gauges |
Total spent to date: $4,850.68 (all prices include tax, shipping, and insurance)
| # | Mod | Details | Notes |
|---|---|---|---|
| 9 | Valved Exhaust | DIY 3" QTP cutout bypass (keep OEM mufflers) | 3" dump, step-down to 2.5" for muffled path |
| 10 | Headers | Skunk2 Alpha 4-2-1 (412-05-1930) + Berk HFC | Best available, stepped primaries, 10-18 WHP |
| 11 | Intake Manifold | Skunk2 Ultra Street + bored stock TB (66mm) | Larger plenum, shorter runners, DBW compatible |
| 12 | Pulleys & Harmonic Balancer | ATI Super Damper + NST accessory pulleys | Proper damping + reduced parasitic loss |
| 13 | Flex Fuel & Fuel System | Flex fuel sensor + ID725 injectors + Acuity rail + DW300C pump | E85 capable, 5-15 WHP on NA over pump gas |
| 14 | Clutch Hydraulics | Hybrid Racing HYB-CMC-01-20 complete kit | 170k-mile reliability upgrade, improved pedal feel |
| 15 | Suspension | BC Racing BR coilovers + full bushing refresh + sway bars + camber kit | Complete suspension overhaul — coilovers, bushings, geometry correction |
| -- | In-Car PC | LattePanda 3 Delta permanent install | Controls FlashPro + exhaust valve |
Each mod has its own folder with:
- overview.md — What the mod is, why I chose it, part numbers
- install-guide.md — Step-by-step install instructions (where applicable)
- brainstorm.md — My research, alternatives I considered, pros/cons
- purchasing.md — Parts list with part numbers and prices
07-Hondata-FlashPro/Temporary-Setup/— Getting started with a laptop before the permanent install07-Hondata-FlashPro/Permanent-LattePanda-Install/— Full guide for the in-car PC build08-Valved-Exhaust/— My DIY valved exhaust design, parts, and planningdocs/— General reference documentsdocs/vehicle-specs.md— Full stock specification referencedocs/mod-order-and-maintenance.md— Chronological mod order + 170k-mile maintenance plandocs/install-references.md— Install guides, community links, and search terms for every mod
The whole build log compiles into two printable PDFs so I have everything in one place at the garage:
- 2009-Civic-SI-Build-Guide.pdf — Full build guide: vehicle specs, mod order, every mod overview, and install references, with a title page and table of contents.
- 2009-Civic-SI-Mod-Order.pdf — Standalone chronological mod order + maintenance plan.
Both are generated by generate-pdf.py, a Python script that reads the repo's markdown and renders it — headings, tables with multi-line cell wrapping, bullet/numbered lists, and code blocks — into the two PDFs above. It's the first real coding I've done on this project and it's still rough around the edges. Coding is self-taught for me, so the script is deliberately dependency-light: the only thing you need is fpdf2.
pip install fpdf2
python generate-pdf.pyRe-run it whenever the markdown changes to refresh both PDFs.
| Spec | Value |
|---|---|
| Engine Code | K20Z3 |
| ECU Code | PRB (Keihin) |
| Displacement | 1998cc (2.0L) |
| Bore x Stroke | 86mm x 86mm |
| Compression | 11.0:1 |
| Stock HP / TQ | 197 HP @ 7800 RPM / 139 lb-ft @ 6200 RPM |
| Redline | 8000 RPM (fuel cut at 8200 RPM) |
| Transmission | 6-speed manual, 4.764:1 final drive, helical LSD |
| Stock Exhaust Diameter | 2.36" (60mm) from cat back |
| Fuel | Premium 91+ octane required |
| OBD2 Port | Under dash, left of steering column |
| Interior Fuse Box | Driver side lower dash, behind removable panel |
| Fuse Type (Interior) | Mini blade |
See docs/vehicle-specs.md for the complete stock specification reference.
- Discord: discord.gg/lxvelabs — questions, help, or to talk through this project
- GitHub: @LxveAce
- Email: lxveace@proton.me
- Website: lxveace.com
Personal build log by LxveAce. Not a product — just my car, documented in the open.