The URGE designs S1000RR Jerk Camshafts were developed to support our S1000RR based V-8 motor for our 33 Evo Hypercar project.  We stock blank billet cam cores in bulk and machine 5-10 sets at a time for our profiles.  We can also make custom profiles as specified by the customer.  Currently, we only stock Gen II (2015 to 2018) billet cores but we are searching for a reliable supplier for the Gen III (2019+) ShiftCam IN cores.

Intake cam

Valve timing is critical with cams as it determines what RPM range an engine makes torque.  The single most important camshaft event is when the intake valve closes.  Air inertia dictates optimal intake valve closing to maximize cylinder filling in a particular RPM range.  Although we have a set the centerlines to general work for most applications, the Gen II S1000RR has adjustable cam gears and there are potential gains to be made with complimenting header, exhaust, ITB and bottom end performance parts.  Make sure there is adequate piston to valve and valve to valve clearance if you are changing cam timing or have other modifications that could reduce clearances.

The next most important camshaft parameter is intake cam duration.  Intake cam duration is optimized based upon manifold pressure and the primary engine operating range.  Intake duration along with lift determines the maximum amount of air an engine can consume and ultimately the torque that can be made at specific RPMs.  We have set our intake cam duration and lift to superbike race cams improving midrange and top end power compromising some low-end.

Exhaust cam

Exhaust valve duration and lobe separation angle are the next most important camshaft timing events that define camshaft overlap which influence air momentum and cylinder pressure.  Intake valve closing and duration determine how much power cams can make, and exhaust timing events adjust the range and peak of the torque curves.

We studied dozens of torque curves and flow charts to understand what size exhaust cam we should pair with our intake cam to maximize torque gains across the largest RPM range possible.  The S1000RR OEM head has a higher EX flow compared to other motorcycles and we have optimized the exhaust cam duration and lift to support this.

Performance Profile

The S1000RR is a highly optimized liter bike motor producing 10-20 more hp than competing literbikes, even providing similar power and almost as much torque as the ~1100cc bikes over the last few years.  There is limited opportunity to make gains on arguably the most advanced literbike package over the last decade.

After studying dozens of intake profiles for the S1000RR and other top literbikes, we saw consistency in and the most potential with Superbike intake profiles.  Superbike intake profiles extend the torque curves as much as possible providing the most gains at higher RPM, while making some gains in the midrange and sacrificing some low-end power.  We felt this was the best compromise for aggressive street and track riding use.  From there, we adjusted the exhaust lobe profile to support the intake/exhaust flow ratio that optimizes the broadest possible torque curve.

Tune required

We understand the desire for a drop-in camshaft that doesn’t require tuning.  However, the OEM ECU can only compensate for a limited increase in air.  These gains can easily be achieved by a header or exhaust, so we had no desire to design a camshaft with limited gains.  URGE designs Jerk Camshafts are a significant improvement in airflow over OEM camshafts and tuning is required to install and maintain optimized air fuel rations and spark timing.

Jerk

Another key focus of Jerk camshafts and where we derived its name is reducing jerk or the rate of change of valve acceleration.  Higher jerk increases valve train wear and the potential of valve, spring, or retainer failure.  Despite having >14% more intake lift than OEM, our Superbike profile has reduced valve jerk vs OEM.  Jerk Camshafts profiles are designed via advanced camshaft software to unsure as low cam jerk as possible while optimizing valve lift and duration.

CNC Machined

Jerk Camshafts are ground using computer numerical controlled (CNC) machines to create precise copies of our computed added design (CAD) camshaft profiles.  Camshaft dimensions on checked on a computer-controlled cam gauge to ensure ten millionths of an inch accuracy!

S7 Tool Steel

Jerk Camshafts use tool steel alloy which is harder and stiffer than common billet steel and significantly stiffer than cast steel camshafts.  Stiffer material reduces the axial twist along the cam during higher RPM use reducing cam deflection between cylinder 1 closest to where the cam is driven and cylinder 4.  This will improve torque consistency between cylinders providing a more balanced and tuned motor freeing up a few HP.

Carpenter Racing Valve Spring kit

The Carpenter Valve Spring kit is a single spring design reducing weight vs the OEM dual spring intake improving valvetrain stability at higher RPM.  Additionally, Carpenter Racing valve springs are heat treated and shot peened reducing stress risers and potential crack initiation points significantly increasing longevity and maintaining full spring pressure throughout its lifetime.  Finally, the Carpenter Racing valve spring kit use Ti-17 titanium alloy retainers which is 30% stronger than typical Ti 6Al4V and 7 points harder on HRC scale eliminating wear and strength issues on typical titanium retainers.