Kenne Bell packs the punch of a bigger blower into its 3.2-liter Mammoth
By Steve Turner
Photos courtesy of Boost Works
Like mobile phones the trajectory of the positive-displacement supercharger development seemed headed toward larger and larger units. However, eventually there are limitations on how much blower you can fit under the hood of a modern Mustang. So, color us intrigued when we learned that Kenne Bell was releasing a new supercharger that would sit between its popular 2.8- and 3.6-liter Mammoth units.
As it turns out, the move came at the apex of customer desires and Kenne Bell capabilities. It seems that the want for a bigger blower was strong, particularly amongst the GT500 crowd. However, not many people wanted to make the moves necessary to add the bigger hardware. This demand begat the new Kenne Bell 3.2-liter supercharger.
â€œNo one liked the idea or the cost of the K-member and lowering/motor mount kits or aftermarket hood required to clear the externally large 3.0-liter superchargers,â€ Jim Bell of Kenne Bell explained. â€œAnd, everyone wants a 3.0-liter. Thatâ€™s OK on Shelby Super Snakes because the car comes with a new Shelby hood. So we bored out the case to 3.2-liters, which is one of the big advantages of the billet case.â€
â€œWe donâ€™t have to do a new casting for every supercharger size. This was my design concept from the onsetâ€”two cases, one for 2.-1, 2.6-, 2.8- and 3.2-liter blowers and one for 3.6-, 4.0-, 4.2- and 4.7-liter blowers,â€ Jim added. â€œLook at the 3.2 concept as a billet small-block that can be made into a big-block by boring and stroking (with a longer case length).â€
The billet cases design and scalable rotors is what allowed Kenne Bell to offer a new creation to meet the bolt-on desires of its customers.
â€œThe case is a billet extrusion that can be both bored and lengthened for larger and longer rotors. We can also change the screw rotors for increased or decreased threads (like fine or coarse threads) for displacement. My goal was always to offer both the largest and most efficient 2-, 3- and 4-liter superchargers…â€ Jim said. â€œSince the 3.2 shares the exclusive Kenne Bell 4×6 lobe rotor concept, which will pump more air and boost at a lower temperature than 3×5 or 4×4, it can match our 3.6 up to 24 psi in both power consumption and charge temps.â€
As such, when we learned that the crew at Boost Works in Katy, Texas, would be installing one of these new units on a lightly modded 2014 Shelby GT500, we were excited to follow along and see how the blower fits and performs. They chose to install it on a Adeel â€™s 2014 Shelby GT500 with the Performance Pack, which came to them with a wounded number-five cylinder. They repaired the cylinder and revved up the combo a bit to get it ready for the new blower.
â€œAround the time that the engine was going together, I got a phone call from Jim Bell over at Kenne Bell. We were discussing the recent success of our 2015 Mustang GT (featuring their 3.6LC Mammoth supercharger), and the ongoing development of their shelf-stock system. During that call, I was talking with Jim about how much work had to be done to fit the huge 3.6LC supercharger under the hood of our GT. He informed me of a new slim-case 3.2-liter head unit that they had been developing,â€ Travis Burelle of Boost Works explained. â€œApparently, this head unit shared the same footprint as the 2.8-liter case. Even better, the IATs were dramatically lower in testing than the 2.8. They were on par with the 3.6-liter! After discussing our 2014 GT500, we decided that we would test one of these new 3.2-liter head units to see just how much more efficient it would be over the stock 2.3-liter TVS and the KB 2.8â€¦â€
While they eventually plan to step up Adeelâ€™s car with a 6.0-liter big-bore engine, they opted to fix that stock engine in the meantime and set the engine up to live through Houstonâ€™s 100-degree summers. Eventually they will crank up the boost and feed it with E85 on the way to that new engine combo, but for the moment the idea was just to see what the new supercharger was all about.
â€œThe car received a set of our GT500 billet blower cams, valve springs, and the ports were left largely untouched. The heads received just a valve job, and some minor clean-up in the bowl area. Thankfully the block was undamaged, and we were able to install a new OEM piston/rings without any fuss. The car barely had 1,000 miles on the odometer, so everything sealed up just fineâ€¦â€ Travis elaborated. â€œWe beefed up the sway bars, and installed a set of billet end-links. The car sits on True Forged Chicanes, wearing Toyo R888s out back, and Michelin Pilot Super Sports up front. A beefier clutch/flywheel, MGW shifter, and built 8.8 axle out back wraps things up. To feed the beast, 750cc injectors were installed, along with Kenne Bellâ€™s Pro Series 20-volt dual Boost-a-Pump. The new 3.2LC supercharger breathes through a KB 168mm Big Oval throttle body and 5-inch inlet tube.â€
Of course, adding the hardware is one thing, but making the combo work together is another. Boost Works recently partnered with Lund Racing for its custom tuning needs, so they headed for the dyno for a remote-tuning session.
â€œWith everything dialed in, we strapped the car down on Late Model Racecraft’s Dynojet. Within three hours, we had the car perfectly dialed in. At a very conservative 15.5 to 16psi, 16 degrees of timing, and a safe 11:1 air/fuel ratio on 93 octane, the car put down 786 rear-wheel horsepower and 710 lb-ft of torque. We were pleasantly surprised with the numbers, but we were even more pleased to see the IAT’s only get up to 128 degrees, on a 85 degree day,â€ Travis enthused. â€œThis was after four pulls on the dyno, and no cool-down. Just single fan blowing across the OEM heat exchanger provided enough cooling to keep things in check. Subsequent highway pulls with better airflow showed even lower IAT’s of 115-118 degrees max! So, Kenne Bell definitely has a winner with this new 3.2LC Mammoth system. We can’t wait to see what it does at higher boost levels on a built short-block. Happy with the numbers made on the dyno, we called it a day.”
You can watch the dyno runs right hereâ€¦
â€œWeâ€™ve seen people make big numbers with the stock TVS, but the curve doesn’t look quite as nice, and the IATs are screaming at those blower speeds on stock heat exchanger/pump/intercooler. We’re barely scratching the surface of what this new 3.2 can do, and that makes us very happy,â€ he added.
Travis expects that this 3.2-liter blower will eventually support four-digit power levels, but for now they plan to see what the current combo is made of on the Texas Mile, while running it alongside the shop’s KB 3.6-liter-boosted 2015 Mustang GT.