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Kenne Bell Supercharger Mammoth 2.8H Kit Upgrade
We Test Kenne Bell's Latest Mammoth Kit For '03 Cobras And Crank Out 643 RWHP With Pump Gas.
The first step is the obvious one--we had to remove the factory supercharger setup. Since we recently swapped on a ported Eaton on our Cobra, we already knew how to handle this. After about an hour of disassembling the array of metric and standard hardware, we found ourselves looking at a 32-valve long-block. The next step involved preparing the engine compartment to receive the massive new blower assembly.
If you are intending to keep your Cobra all-original for a future ground-up restoration, you should stop now. The reason why we say this is because there is some cutting of the factory sheetmetal required. But for the anticipated massive horsepower gains, we forged ahead.
The next order of business is to make room for the massive cast-aluminum inlet assembly that connects the rear of the blower case to the throttle body. The inlet is one of the key elements in the Mammoth kit, so clearancing the firewall is required. Simply trim the lip where the instructions tell you to, and move on to installing the blower assembly, with the intercooler, onto the intake manifold. Once it's bolted into place, break out the soldering iron because we're about to extend some wiring.
Since the design of the Mammoth kit relocates some key items such as the TPS (Throttle Position Sensor), Mass Air Flow meter (MAF) and the Idle Air Control (IAC) motor, you'll need to extend these connectors with the included wiring kit. Also, you'll need to replace the factory throttle cable assembly with the new supplied one and then perform some battery cable extending. Not wanting to take any chances, Kenne Bell gives a good background in the instruction manual on how to properly solder, seal, and re-connect the wires. In addition, the solenoids and vacuum control systems need to be carefully relocated to the firewall to make room for the humongous inlet piping.
The ginormous inlet pipe is what gives the Mammoth kit its name. Looking more like a sewer pipe that anything else, this 4.5-inch assembly connects the 75mm throttle body (that's two 75mm blades, by the way) to the air filter, which mounts in the inner fender. To make this all happen, you'll have to cut a hole where the battery tray used to sit and the template included makes it easy to perform. We used a small pneumatic reciprocating saw to make short work of the fenderwell area. With the tube positioned and in place, we clamped on the massive 1,200-cfm air filter from underneath after trimming the inner fender itself.
When you have this much air moving in, you'll need the fuel to match. Kenne Bell normally provides its Boost-A-Pump system to increase the voltage of the two factory fuel pumps for increased overall fuel system capacity, but in the end the factory 39-pound injectors are simply not up to the task of fueling this fire. So, we relied on the knowledgeable injector experts at RC Engineering in Torrance, California to help us. It was determined that a set of 750cc/hr injectors would fit our bill. Since RC Engineering only specializes in high performance, we knew that its balanced, matched and blueprinted set would help us achieve our goals (read the sidebar for more information.) With them installed, the injectors would provide the fuel as we climb the horsepower ladder.
Finishing up, we set the car up for 21 pounds of boost. To do so, we relied on a pulley system from Metco Motorsports, which allows us to vary the pulley ratios and of course, boost level. Metco's interchangeable lower pulley system allows you to alter the pulley ratio without using an excessively small upper pulley for adequate belt wrap for reduced slippage and greater reliability. In addition, Metco also offers improved billet aluminum idlers, which we decided to upgrade our Cobra with to provide more precise belt alignment and of course, eye candy. We started off with a 7.4-inch diameter crank pulley (0.1 inch smaller than stock) and used KB's 3.25-inch upper pulley, which incidentally, is the largest diameter unit that will clear the factory hood.