The goal of headwork is to increase airflow and velocity in and out of the combustion chamber. Most Headwork shops focuses on increasing the port size as an easy way to increase flow, however going big significantly reduces air velocity. Air velocity (air flow divided by port area) is what improves torque and transient response (RPM acceleration). When Air velocity is too low, the engine can feel “Lazy” at lower RPMs and your motor will only operate in a very Narrow RPM range.
S2000 OEM Ports are Too Big
A stock S2000 head flows roughly 330 CFM (28”of H2O) and OEM valve lifts which out flows every other 4 valve production head. The problem with the S2000 is that it has relatively large ports as Honda tuned it for high RPM. This is why the F20C (MY00-03) has a noticeable lag below 5000 RPMs. The engine simply does not have enough stroke, compression or displacement for such large ports. This is also why F22C (MY 04-09), with an extra 8% of stroke/displacement, responds as low as 3000 RPM and makes 10+ more HP at 500 less RPM. The larger stroke/displacement increases the air velocity moving through the large ports.
Larger ports explain why headwork has not been a popular S2000 modification to date. Most head porters simply make the ports even larger which will increase flow but reduce air velocity making the engine less responsive. Although the top end may pick up some HP with larger ports, the midrange and low end will bog down significantly reducing overall performance.
Focus on flow with less porting
URGE Velocity S2000 heads can flow over 380 CFM depending on application, with our Storker Port flowing right at 400 CFM which is a 20% improvement over stock. Amazingly, we can also improve exhaust flow greater than the OEM intake flow proving a 25% improvement significantly improving exhaust flow and improve intake pull through.
Stroker Velocity Head vs Stock
Again, these gains are achieved with minor port size increase, focusing mainly on modifying the port shape and seat. The minimal increase in port size along with a dramatic increase in flow translates to a large increase in air velocity creating a responsive engine. We can achieve a 15-20% improvement in head Intake flow & 25-30% increase in Exhaust flow. This will not directly translate into 12-25% increase in horsepower but the potential to increase horsepower based upon tuning and restrictions in the intake or exhaust systems.
Boost Velocity Head vs Stock
- 30 to 60 HP gain on 16.5 PSI turbo motor, 500+ RPM faster spool
- Bottom line is stock 16.5 PSI, middle line is 16.5 PSI, top line is 18 PSI
2.2L, stock bottom motors
- CNC headwork
- Hand blending & finishing chambers, ports and seats
- New aero valve guides
- New nitride coated stainless steel valves to match valve seats
- New Valve seals
- Valvetrain assembly, We will ONLY assembly with our kit or Supertech H1021D springs
- Adds Inconel EX valves due to hotter turbo/supercharger exhaust temperatures
- Turbo Exhaust port to speed up turbo spool
- Or Supercharger Exhaust port to reduce exhaust back pressure
- Includes all Velocity Headwork
- Adds Larger Intake Valve & Seat; Maximum CFM for 99mm Stroker Motors
• Ultralight & Endurance Single Valve Spring Kit $790
- w/ Titanium Retainers ($200), Steel seats ($90) & valve locks ($90)
- Tested to 11,000 RPM
- High Fatigue Life, Tested with zero Pressure Drop after 1 season of racing
- MUST have for 14mm+ Stroker Cams
• O-Ring cylinder head $250
• ARP head studs $140
• Cometic head gasket $100