Behind the Curtain with Hoonigan x SK2

When it comes to entertainment and tuner horsepower, there's no better match than Hoonigan and Group-A. In this latest feature from Hoonigan's Project Car series, they deliver a K24 to our doorstep and tell us to give it the full Skunk2 treatment.

This engine was chosen and built for one specific goal: to sing the sweet, sweet tune of 10,000 RPM! Being who we are and doing what we do, this was a relatively easy feat. Skunk2 features all hardware necessary to bring this engine up to snuff for not only being able to reach 10K, but for being able to make high, reliable horsepower doing so.

'One mo' again!'

Suppy and Mike Attempting the fusion dance

Always coming up with interesting and inventive ways to showcase products and builds, the Hoonigan crew are always massively entertaining and all-around good guys whom we enjoy hosting at our facility.

This build being no exception, the idea was that their built K24 be bolted to our SuperFlow engine dyno and tuned by the experts here at Group-A. The engine itself was built to showcase the best parts from multiple manufacturers and, once proven to be 10,000RPM capable, be given to one lucky winner from the Hoonigan viewership.

For a 2.4 Liter to scream to 10,000RPM reliably, an engine needs to be built to a very high spec to avoid any risks of failure; catastrophic or otherwise.

As a baseline, the Hoonigan K24 featured:

• • Skunk2 Ultra Race Intake Manifold
• • Skunk2 K series Composite Fuel Rail
• • Skunk2 Black Anodized K series Timing Chain Covers
• • Skunk2 Pro K Series Exhaust Cam Gear
• • Skunk2 Valve Cover Hardware
• • Grams Performance 750cc K Series Fuel Injectors
• • 4 Piston 156v2 CNC Cylinder Head
• • Ferrea 6000 Valves and Valvetrain
• • Originally: 4 Piston RR3 K Series Camshafts (See below for camshaft info!)
• • New Valve Seals and Valve Guides
• • Wiseco 87.5mm 11.0:1 Pistons
• • Manley K24 H-Beam Rods
• • King Race Main and Rod Bearings
• • ATI Street Damper
• • ARP Head Studs
• • Hondata Intake Manifold Gasket
• • K-Tuned Oil Pan with Hardware
• • K-Tuned Swivel Thermostat Housing
• • K-Tuned Timing Tensioner

Built With Purpose

Hoonigan Crew attempting to interpret the code of the Matrix

The Hoonigan K24 engine build was packed with the highest quality parts that any individual would love to have. A completely refreshed K24 block was supplied by JDM of California featuring forged internals and a head built to breathe well past the goal of 10,000RPM, plus bolt-ons to cover every aspect of what was deemed necessary (see: "all of it!").

The engine was then brought to us here at Group-A for engine dyno testing and tuning to ensure it would reach the goal. We bolted it into our Superflow engine dyno and let resident engineer Daniel do pull after pull while adjusting the fuel mapping, moving from light initial engine break-in runs to seat the piston rings to full WOT (wide-open throttle) runs up to 9,500 rpm.

Hours of footage were captured during this time to have only a few minutes worth pulled and used. As anyone who has experience being around a dyno would know, tuning is a time consuming, tedious process and every precaution must be taken to prevent potential catastrophic failure. One wrong fuel or timing adjustment could be a costly demise to a fresh engine build. Fortunately, with over two decades of tuning expertise, this engine was in safe hands.

A Day Late and 1K Short

Horsepower results with the 4 Piston RR3 camshafts and side exit race header

The end of day one came and went like a blur, but not without its unfortunate disappointments. Hoonigan had promised a 10,000 rpm K24 but the engine just wasn't having it.  Making just over 298 horsepower at its peak, power started dropping dramatically right after 9000 rpm and it was clear something needed to change.

Luckily, here at Group-A we have all of the options and components necessary to bring nearly any engine builders fantasy to life. And, with that knowledge, Skunk2/Group-A Founder and technical mastermind Dave Hsu met with the Hoonigan team and came up with a solution to help achieve their so-far-unachievable goal.

Upon reviewing the dyno sheets and details of the build, Dave had come to the conclusion that there were two problems plaguing the engine and keeping it from reaching full potential. The first being that the currently installed camshafts did not have enough duration to properly fulfill the cylinder volume requirements for 10k rpm due to an improperly selected cam profile. The second was that the chosen side-exit style race header was simply too big for the application, resulting in lower than optimal exhaust velocity and a bit of turbulence that would interrupt exhaust flow.

With the plan in place, Hoonigan left Dr. Charles and Daniel to begin tear down and installation of the planned upgrades that would hopefully help them achieve their goal.

How Much Power Does It Make?!

Dave: "Red Pill or Blue Pill?"

With all of our new Skunk2 components in and ready to spin, Hoonigan came back for day two of dyno testing. With high hopes, they shot a quick overview talking of all that had transpired since the day before.

Daniel and Dr. Charles had installed all of the new Skunk2 components, including our K Series Black-Anodized Billet Timing Chain Cover , K Series Adjustable Exhaust Cam Gear , and our recommended Skunk2 camshafts. Our billet timing chain cover is a two-piece system, allowing removal of the cylinder head without removing the crank pulley or lower timing cover. The Skunk2 Exhaust Cam Gear additionally allows for precise physical cam timing adjustments to ensure maximum potential from the camshafts.

Suppy and Mike joined Daniel in adding the final touch by swapping the side-exit race header out for a more appropriately sized 4 into 1 header and then got swiftly into engine tuning once again. Firing up the engine and quickly ripping through a few runs landed the engine right in the target zone making great power all the way to 10,200rpm!

All the new hardware and the selected cam profile had gotten the team where they wanted to go. And, of course, we finished it off with our 1 of 1 prototype K series valve cover coated a candy red as a special parting gift.

But, the questions still remain: How much power did it make? What cams did we use? What's the deal with that SWEET valve cover?!

Stay tuned for part two of this entry where we cover some of the more technical details of the components we used and why, as well as a reveal of the final dyno chart and horsepower!

Big thanks as always to Hoonigan for coming by and giving an inside look at our operations and showcasing the knowledge and technology that we incorporate into all of our parts.