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Kenne Bell Twin Screw Supercharger Coyote 5.0L Build - Bell Curve
Kenne Bell Comes Full Circle To Build A Hot Blower For The Coyote 5.0L.
It's natural for owners of the original 5.0L to be somewhat skeptical about Ford's use of yet another name from the glorious past. Nostalgia is a hot commodity that only takes you so far.
One of the difficulties associated with a nostalgic name is that it's sometimes difficult for the reality of the current iteration to exceed our memory of the original. Believe me, memories of the Shelby GT350, Boss 302, or even the original 5.0L, are almost always better than the reality. The early Shelby and Boss cars were off-the-charts cool, but they couldn't hold a candle to a Fox-chassis, 5.0L, injected Mustang for outright driveability or performance.
The same holds true for the new 5.0L Four-Valve motor. Those who flourished during the original 5.0L renaissance (the rebirth of Ford performance) no doubt hold the original injected 302 in high regard. It was, after all, responsible for the birth of a performance segment that continues to this day. But although impressive in its time, the performance of the original 5.0L simply can't compare to its modern equivalent. Though they share displacement, it's hard to argue with an extra 187 hp, plus 1,000 extra rpm of usable engine speed and even better fuel economy.
As impressed as we are, we can't shake the itch to go to the next level. We love the new 5.0L, and recognize the benefit of the additional displacement and variable cam timing. These changes combined with higher static compression and a revised intake manifold give the new 5.0L something it sorely needed-a little thing we like to call torque.
Though the new Coyote is an improvement compared to the previous 4.6L, the 5.0L is still down a full liter of displacement compared to the Chevy and Dodge boys. All the trick intakes and cam phasing in the world will not make up for the missing liter of displacement. The new 5.0L can match them in terms of real-world performance, but it must rely on a lighter curb weight to offset the missing displacement. Luckily for enthusiasts, the aftermarket is in full swing on the 5.0L, and that includes the Acme boost-masters over at Kenne Bell.
Case in point, this new 5.0L supercharger kit from Kenne Bell will add as much as 200 rwhp to your new 5.0L at roughly 9 psi of boost. Naturally, the highlight of the kit is the Kenne Bell Twin Screw supercharger. Our test involves a 2.8L, liquid-cooled supercharger, but other configurations are also available. The KB blower brigade for the 5.0L includes the 2.8L (standard and liquid-cooler), and the liquid-cooled 3.6L. There are, however, those who insist on nothing but the biggest and baddest, and Kenne Bell now offers such a jetpack. The 4.2L Twin Screw is capable of supporting over 1,400 hp on the right application.
Blower choice comes down primarily to online bragging rights, but rest assured, any of the available superchargers will transform your 5.0L into a serious muscle Mustang. Given the elevated static compression, the 2.8L will support more power than the stock components are likely to withstand, especially on pump gas. To combat the high compression, the Kenne Bell supercharger kit includes a number of countermeasures, including precision tuning, ultra-efficient intercooling, and a dedicated cold-air intake. Knowing that the power output of the blower motor is only as good as the greatest restriction, Kenne Bell designed the kit to maximize airflow to the blower. Maximization started off with a dedicated filter that flows over 2,000 cfm. Attached to the filter is a cold-air intake measuring a whopping 4.5 inches in diameter.
The custom inlet system is also home to the mass air meter. Repositioning the mass air meter naturally required reprogramming, as did the installation of the larger injectors. Completing the air inlet system is the Mammoth intake manifold and throttle body. Testing demonstrated that the factory throttle body is the most restrictive element in the system, but as usual, Kenne Bell had a cure (see sidebar on throttle body testing).
In addition to the massive intake, the kit also features a new air-to-water intercooler system. Knowing the new motor features 11.0:1 compression, KB increased the size and efficiency of the intercooler core to maximize heat dissipation. According to Kenne Bell, the intercooler system employs as large a core as space constraints allowed.
The air-to-water intercooler system includes a reservoir, circulation pump, and separate heat exchanger to rid the system of unwanted heat. Knowing enthusiasts will be cranking up the boost, Kenne Bell has already designed an optional heat exchanger that looks like a second radiator. This heat exchanger adds both thermal capacity and increased surface area to improve heat dissipation.
The cold-air intake and air-to-water intercooler combine with the precision tuning to allow maximum boost on the high-compression motor. The provided tune will be based on the octane rating of the available fuel. The motor will not make as much power on 91-octane as it will on the 94-octane fuel available in other parts of the country.
As with all Kenne Bell supercharger kits, the boost is controlled by the combination of crank and blower pulleys. The standard 9-psi kit tested here features a stock (6.6-inch) crank pulley, combined with a 4.125-inch blower pulley. This drive ratio produces roughly 9 psi of boost on the stock motor at 7,000 rpm.
As luck would have it, the 39-lb/hr injectors supplied with the kit requires no fuel pump upgrade, as Ford saw fit to up the supply voltage to the factory pumps already. According to Kenne Bell, the stock pumps on the 5.0L are fed by 16 volts right from the factory, and are capable of supporting the power produced at 9 psi with no trouble. The blower kit also employs the stock fuel rails.
Early-bird 5.0L owners receive a special treat, as the first kits will feature billet aluminum lower intake manifolds. Rather than have enthusiasts wait for the cast versions, Kenne Bell decided to have billet aluminum manifolds machined to fill the many orders. According to Kenne Bell, there will be no difference in the power offered by the two manifolds-the billet stuff just adds to the cool factor.
As with all of the kits, the 5.0L supercharger system incorporates a bypass valve to reduce parasitic losses and inlet charge temps under cruise conditions.
The technical aspects of the new supercharger kit are all well and good, but we want cold, hard facts. Testing was performed on an '11 5.0L Mustang equipped with an automatic transmission. The numbers offered for a stick Stang will be slightly higher since the wheel power output is up by 15-16 hp.
Run on a DynoJet, the stock Coyote pumped out 361 hp and 349 lb-ft of torque. After installation, output jumped to 564 hp and 482 lb-ft of torque. That represents a gain of just over 200 rwhp at roughly 9 psi of boost.
Our testing was done on 94-octane fuel, so results with the 91-octane tune will be somewhat less due to the required reduction in ignition timing. As impressive as the 5.0L is in stock trim, it simply does not compare to getting behind the wheel of a boosted combination pumping out over 560 hp.
This Acme jetpack is a serious threat to your license, especially since the Coyote cockpit is so well insulated. Were it not for the self-shifting automatic transmission, the factory rev limiter would quickly become your new BFF. Even more impressive is the fact that the 2.8L twin-screw supercharger was just getting started. Running at roughly 40 percent thrust, we can only imagine a built 5.0L running at Thrustis Maximus. Competition beware!
Size Matters:Throttle Body
Contrary to popular belief, throttle bodies are not magic. They are simple devices that control the airflow to the engine. In the case of the new 5.0L Mustang, Ford equipped the 302 with a 80mm throttle opening. For the guys that grew up with the original 5.0L, that is a far cry from the 60, 65, or 70mm, or the throttle bodies run on the fuelie motors.
Testing throttle bodies is sometimes confusing, as the power gains offered by a larger or higher flowing throttle body are determined by a combination of the flow rate and power output. On our supercharged 5.0L test motor, swapping out the stock 80mm throttle body (flowed 1,125 cfm with radiused entry part of the KB SC air intake) for the 168mm oval throttle body (flowed 2,150 cfm or 2,350 cfm with radiused entry) resulted in 17 hp.
As we have come to expect of change in airflow, the power gains increased with engine speed. The reason is that the 80mm throttle body became more and more restrictive as the airflow needs of the motor increased. The same thing happens when we crank up the boost or power output of the combination, as the higher the airflow needs of the motor, the more restrictive the 80mm throttle body becomes. Tested at 600 hp, 700 hp or even 800 hp, the larger 168mm throttle body might be worth as much as 50 extra hp!