A Fourth-Gen MegaCab Ram Cummins Packing a 48RE, an S475, and 1,000 HP
No, it’s not just another Cali-lean Cummins on ‘Forces. Paul Szczypta’s ’12 Mega Cab runs as good as it looks thanks to a 48RE swap, state-of-art fueling, an S475, and spot-on tuning. On the dyno, it’s a proven four-digit performer. On the street, it’s extremely drivable. “I don’t drive it to work every day, but I could,” he tells us. “It doesn’t smoke and it’s not inconvenient to drive. In fact it drives smoother than most people think.” Of course, the right amount of throttle position can set the all season’s ablaze in a hurry—but with 1,775 lb-ft of torque on tap that comes with the territory.
Now for the fun part: the 63,000-mile 6.7L Cummins’ bottom-end is all original. On top of that (no pun intended), the head has never even been pulled. To be sure, the engine has head studs, but each ARP Custom Age 625+ fastener was threaded into the block one at a time. That process was repeated for the valve springs, a set of 103-lb springs from Hamilton Cams getting the nod. Hamilton’s extreme duty pushrods conclude the short list of internal engine mods Paul’s barely-broken-in Cummins has been treated to. Operationally, a coolant bypass system from Fleece maintains coolant temp across all six cylinders.
Stainless 2G Swap and S475
When Paul’s plans for his Mega Cab first took a turn toward serious, he ran a second-gen turbo swap and an S472 from Stainless Diesel. After that, he installed an S366 over S480 compound arrangement and watched the boost gauge tap 90-psi for a while. Currently, he’s gone back to a second-gen single turbo configuration, which revolves around the use of a Stainless S475/87/1.00. The truck’s tuning and transmission have been matched to the big 5-blade charger for optimum high-rpm performance and low-end drivability. A Mega intake manifold from Pusher and a Steed Speed exhaust manifold sum up the rest of the engine’s airflow and exhaust mods.
Dual Pumps, 200-Percent Injectors
A big part of Paul’s 1,000hp recipe lies in his injector and pump choices. The fully balanced and calibrated set of injectors were built at S&S Diesel Motorsport, complete with internal body mods and 200-percent over nozzles. Adequate rail pressure is maintained thanks to a dual CP3 kit from Fleece Performance. One of Fleece’s 10mm stroker pumps sits in the factory position while a stock 6.7L Cummins CP3 gets belt-driven up top. The injection system receives plenty of support thanks to a 165-gph FASS system, which supplies the CP3’s with 13-15 psi worth of fuel at all times.
With an original goal of 750 to 800 hp, Paul took a chance and kept the G56 manual in the mix, in the beginning. Thanks to some sensible driving, it lasted four years before fourth gear shattered under full power. Then, instead of gambling on a second gear box , he enlisted the help of Wilson Patterson Diesel, who spearheaded a 48RE swap. To make sure Paul’s power goals were achieved and the automatic survived in this 8,100-pound application, WP Diesel fitted the 48RE with Sun Coast’s billet, 27-spline input shaft. A TCS 300 Maraging steel intermediate and 29-spline billet-steel output shaft also made the cut, while a Sun Coast triple-disc converter, spec’d with a 2,200-rpm stall speed, handles power transfer. Sun Coast’s plug-and-play E618 valve body, tuned through the use of a PCS 2800 stand-alone controller, controls its shifts.
A Tire-Frying Daily
So what does it all amount to? How about a truck that makes a dyno-proven 1,013 hp and is a hell of a lot of fun on the street. Yet even at this power level—and on a stock bottom end, no less—Paul doesn’t bat an eye about taking the truck on out of state road trips. Thanks to his carefully selected turbo, tuning, fuel, and transmission combination, the big Mega Cab is just about as reliable, well-mannered, and refined as 1,000hp gets. Of course, when it’s time for his 21-foot limo to run down the occasional Corvette or light up the rear tires at highway speeds, Paul is more than happy to do it.