This is how to make your B18C GSR perform like a B18C Type R without doing a full engine swap or going wild with internal changes.
Let’s focus on simple, proven upgrades that bring your GSR close to Type R-level power and response — around 190–200 hp (crank) or roughly 170–180 whp on a good tune.
Bonus Tip:
If your GSR is auto-trans, the stock gearing and torque converter will limit results — a manual swap (with LSD) is almost required to fully match the Type R’s driving feel.
TL;DR:
To make your B18C GSR as strong as a B18C Type R with simple mods:
- Swap to Type R-style intake manifold & throttle body
- Install Type R or mild performance cams + springs
- Add performance header & 2.5” exhaust
- Tune the ECU properly
You’ll hit ≈ 190–200 hp crank and enjoy the rev-happy, aggressive VTEC feel of a real Type R.
Goal: Make GSR ≈ Type R Power (Simple Upgrades Only)
Here’s a practical, staged list of the best low-risk bolt-on and tuning upgrades — no bottom-end teardown.
1️⃣ Type R-spec Intake System
Why: The Type R breathes better; its intake manifold and throttle body are designed for top-end flow.
What to do:
- Replace the GSR dual-stage intake manifold with a Type R (PR3 or Skunk2 Pro Series) single-runner design.
→ Simpler, more efficient airflow at high rpm. - Install a Type R or 70 mm throttle body (OEM or Skunk2/Omni).
- Pair with a cold-air intake (AEM, Injen, or custom piping with velocity stack).
✅ Gains: +8–12 hp at the top end, better throttle response and VTEC pull.
(Type R manifold is the #1 mod to wake up the GSR’s top-end.)
2️⃣ Type R or Aftermarket Cams + Valve Springs
Why: The GSR cams are milder; Type R cams open valves longer and higher, letting it rev and breathe better.
What to do:
- Drop in OEM B18C5 (Type R) cams or mild aftermarket Stage 1/2 cams (Skunk2 Pro 1, Toda Spec A, etc.).
- Upgrade to Type R or dual valve springs + titanium retainers (stops valve float over 8,000 rpm).
✅ Gains: +10–15 hp with proper tuning and supporting intake/exhaust mods.
(Even OEM Type R cams transform the GSR.)
3️⃣ Header & Exhaust System
Why: The Type R has a more free-flowing exhaust and header design.
What to do:
- Use a 4-1 or 4-2-1 performance header (PLM Tri-Y, Toda, Mugen replica, DC Sports).
- Add a 2.25–2.5” cat-back exhaust system (Buddy Club, Skunk2 MegaPower, Mugen, etc.).
- Optional: high-flow catalytic converter or test pipe (track use).
✅ Gains: +5–8 hp plus quicker VTEC engagement and lighter sound.
4️⃣ ECU Tune / Reflash
Why: Your GSR’s stock ECU is conservative; tuning unleashes the power of intake, cams, and exhaust.
What to do:
- Use Hondata S300, Neptune, or Crome tuned P72/P28 ECU.
- Retune fuel, ignition, and VTEC crossover for new airflow and higher redline (~8,200–8,400 rpm).
✅ Gains: +10–15 hp from proper optimization and smoother torque curve.
(Tuning is mandatory once you change manifold & cams.)
5️⃣ Type R-spec Clutch, Flywheel, and Gearing (Optional)
Why: Type R revs faster partly due to lighter rotating mass and shorter gear ratios.
What to do:
- Lightweight flywheel (≈ 9–12 lb) and performance clutch (Exedy Stage 1 or Type R OEM).
- If budget allows, use a shorter final drive (4.785) or a Type R transmission (S80 LSD).
✅ Gains: Faster acceleration, sharper throttle feel (no raw hp, but better performance).
6️⃣ Maintenance & Supporting Mods
Before pushing rpm:
- Replace timing belt, tensioner, water pump (if old).
- Use quality oil (10W-40 racing blend) and premium fuel (RON 97+).
- Upgrade ignition (NGK Iridium plugs, new wires).
- Ensure proper compression — a weak base motor won’t benefit much.
**Let’s go detail on a “B18C GSR-to-Type R Spec Conversion” parts list that’s:
✅ Simple bolt-on upgrades (no bottom-end work)
✅ Focused on reliability + Type R-level power (~190–200 hp crank / 170–180 whp)
✅ Practical for street or light track
⚙️ GOAL
Transform B18C GSR into Type R–equivalent power and response
Target: 190–200 hp crank (~170–180 whp)
Approach: Breathing + camshaft + tune + light rotating mass
1. Intake Manifold & Throttle Body Upgrade
|
Item |
Recommended Brand/Model |
Notes |
Est. Gain |
|
Intake Manifold |
Skunk2 Pro Series Intake Manifold (B18C1) |
Direct bolt-on; replicates Type R single-runner flow; more top-end power |
+8-10 hp |
|
Throttle Body |
Skunk2 70mm Alpha Series or Omni Power 68mm |
Increases airflow and throttle response |
+2-3 hp |
|
Gasket Kit |
Hondata Intake Manifold Gasket (thermal) |
Lowers intake temp for better density |
|
2. Camshafts & Valvetrain
|
Item |
Recommended Brand/Model |
Notes |
Est. Gain |
|
Camshafts |
OEM B18C5 Type R cams (or aftermarket like Skunk2 Pro 1, TODA Spec A) |
Better lift & duration, more high-rpm pull |
+10-15 hp |
|
Valve Springs |
OEM Type R dual valve springs or Skunk2/Toda |
Prevents valve float >8k rpm |
|
|
Retainers |
Titanium retainers (Skunk2 / Supertech) |
Lightweight, reduces stress |
|
3. Header & Exhaust System
|
Item |
Recommended Brand/Model |
Notes |
Est. Gain |
|
Header |
PLM Tri-Y Type R Replica or Toda 4-2-1 |
Best balance of midrange & top-end |
+5-8 hp |
|
Exhaust System |
Skunk2 MegaPower 60mm / Mugen Twin Loop / Buddy Club Spec II |
2.25” to 2.5” piping recommended |
+3-5 hp |
|
Catalytic Converter |
High-flow cat (Vibrant / Magnaflow) |
Maintains emissions, minimal loss |
|
4. ECU Tuning Setup
|
Item |
Recommended Brand/Model |
Notes |
Est. Gain |
|
ECU |
P72 OBD1 ECU (stock GSR) + Hondata S300 v3 module |
Best flexibility, datalogging & tuning |
+10-15 hp |
|
Tuning |
Dyno tune by reputable tuner |
Optimize air/fuel, ignition & VTEC crossover (~5,800–6,000 rpm) |
|
⚙️ 5. Flywheel, Clutch, & Drivetrain (Optional but Recommended)
|
Item |
Recommended Brand/Model |
Notes |
Effect |
|
Flywheel |
Exedy Chromoly Lightweight (9 lb) or Fidanza Aluminum (8 lb) |
Faster revving, improved throttle feel |
Rev response |
|
Clutch Kit |
Exedy Stage 1 Organic / OEM Type R |
Smooth engagement, higher clamp load |
|
|
LSD Transmission (Optional) |
S80 Type R LSD gearbox or rebuild with MFactory LSD |
Better traction & shorter gearing |
|
6. Supporting Mods / Maintenance
|
Item |
Brand/Model |
Notes |
|
Cold-Air Intake |
AEM / Injen / custom pipe + velocity stack |
Better flow, cooler charge |
|
Spark Plugs |
NGK Iridium BKR7EIX |
Reliable spark under higher load |
|
Ignition Wires |
NGK / MSD |
Consistent ignition |
|
Fuel Pump (Optional) |
Walbro 255LPH |
If you plan more upgrades later |
|
Fluids |
Motul 10W-40 / Red Line MTF |
Stable at high rpm |
|
|
Approx. HP (Crank) |
Approx. WHP |
Notes |
|
Stock GSR |
170 hp |
~145 whp |
|
|
Bolt-ons only (intake, exhaust, tune) |
185 hp |
~160 whp |
noticeable |
|
Type R-spec full combo (manifold, cams, tune, exhaust) |
195–200 hp |
170- 180 whp |
= Type R level |
|
Fully optimized tune w/ flywheel |
200–205 hp |
180- 185 whp |
Slightly above stock Type R |
|
Component |
Cost Range |
|
Intake manifold + TB + gasket |
$550- $700 |
|
Cams + valve springs + retainers |
$700- $1,000 |
|
Header + exhaust |
$700- $1,200 |
|
ECU + Hondata S300 |
$550- $650 |
|
Tuning (dyno session) |
$300- $500 |
|
Flywheel + clutch |
$600- $900 |
|
Total (Full Type R-spec conversion) |
$3,000- $4,500 USD |
🔑 Key Takeaways
✅ Type R-level power is achievable on GSR without internal work.
✅ Prioritize manifold + cams + tune — that’s 80% of the gain.
✅ Keep the motor healthy — compression & oil pressure are key before tuning.
✅ You’ll have a rev-happy, high-strung GSR that performs like a true B18C5.



