MORE POWER & RELIABILITY
DITCHING THE FAILURE-PRONE VGT TURBO ON FORD’S 2011–2014 6.7L POWER STROKE
Ditch the failure-prone VGT turbo on Ford’s ’11-’14 Power Stroke.
INSTANT THROTTLE RESPONSE, BIG TORQUE, AND THE ability to get loads moving in a hurry were great selling points for the 2011 Super Duty. Thanks to a variablegeometry turbocharger, reverse-flow cylinder heads, and a Bosch injection system utilizing piezoelectric injectors, Ford’s 6.7L Power Stroke V-8 packed 400 hp and 800 lbft of twist when it debuted. However, power ratings on paper don’t always pan out in the real world. With roughly 50 percent of all modern diesel trucks being equipped with some sort of programmer or other power adder, it didn’t take long for 6.7L Power Stroke owners to find the weakest link in the chain: the Garrett GT32 SST turbo.
Equipped with variablegeometry technology, a ceramic ball-bearing center cartridge, and an electronically activated internal wastegate, the GT32 SST
had all the bells and whistles but proved to be a big restriction for the engine. The dual compressor wheels sat back-to-back on a common shaft, but their small 46mm inducers yielded a power curve that ran out of steam before 3,000 rpm, not to mention that the turbine side was undersized by today’s standards. Once the
6.7L engine is saddled with a programmer, the restrictive GT32 SST can produce shaft speeds in excess of 150,000 rpm. In layman’s terms, the factory turbo is a ticking time bomb once it’s asked to cope with power levels beyond stock.
Eventually the fueling added by a programmer will overspeed the turbo, causing it to self-destruct. This places truck owners in a unique dilemma: spend $1,900 on an OEM replacement unit that might meet the same fate, or invest in a proven alternative.
Enter Maryland Performance Diesel’s budget turbo kit for 2011–
2014 Fords. The company’s system replaces the factory charger with a time-tested unit from BorgWarner while reusing the factory intercooler piping and the upper and lower intake manifolds. If you’re the owner of a 2011–2014 Super Duty in need of a turbo, you should consider this option. For $2,725.95 this system adds unmatched reliability to your truck, along with a noticeable bump in power.
11While the Garrett GT32 SST turbocharger (left) found on the 2011–20146.7L Power Stroke is state-of-the-art and a fascinating piece, it’s notorious for overspeeding when pushed hard. Luckily, aftermarket companies like Maryland Performance Diesel (MPD) offer a sound solution: a budgetfriendly, bolt-on system that replaces the problematic turbo with a proven one from BorgWarner (right). When it comes to the Garrett GT32 SST facing off against the BorgWarner S366 SX-E, it’s a classic case of complex and intricate versus simple and proven. Exotic versus conventional. Contradictory in nearly every way, the GT32 utilizes variable-geometry technology while the S366 SX-E is fixed geometry. The GT32 features dual cast 46mm compressor wheels compared to the S366 SX-E’s single 66mm forged milled wheel. A ceramic ball-bearing center cartridge resides in the GT32, whereas a journal bearing center section can be found in the S366 SX-E.
44 Up-pipes with heavy-duty expansion bellows and the appropriate mounting gaskets are also included in MPD’s budget turbo kit. The uppipe on the left connects to the passenger side exhaust manifold, while the unit on the right links to the one on the driver side. If seeing up-pipes configured in this unconventional fashion confuses you, remember that the 6.7L Power Stroke utilizes reverse-flow cylinder heads. This means the exhaust manifolds reside next to the lifter valley (where the intake manifold would be on a traditional V-8).
3 In order to work in conjunction with the factory hot-side charge air pipe (the tube that spans from the turbo to the intercooler), MPD modifies the compressor housing outlet of the S366 SX-E turbo. And because this connection point sees the most boost, MPD machines grooves into the edge of the outlet (in addition to the bead on the end). This allows the supplied 3 intercooler boot a rough surface to grab onto and essentially rules out the possibility of blowing an intercooler boot under extreme pressure.
6 After the coolant and oil lines were disconnected from the factory turbo and the wastegate solenoid harness unplugged, the GT32 was finagled under the cowl and off of the engine. Then the pedestal gasket supplied by MPD was installed, followed by the S366 SX-E (shown). To simplify our installation, MPD bolted the S366 SX-E charger to its respective billet-aluminum turbo pedestal and installed the braided stainless steel oil feed line prior to shipping us the kit. 6
5 Gaining access to the factory turbo takes some time, with the air intake, radiator hoses, intercooler pipes, air intake valve, and upper and lower intake manifolds all having to be removed before enough room exists to loosen the turbo’s four pedestal bolts. To unbolt the factory uppipes from the exhaust manifolds, both the passenger-side and driver-side inner fenderwells were removed. 5
2The exhaust side of the BorgWarner S366 SX-E offered in MPD’s budget turbo kit features a 73mm turbine wheel (exducer) in a quick-spooling, non-wastegated 0.91 A/R housing, and a T4 turbine inlet flange. While the factory turbo requires both coolant for cooling and oil for lubrication, theS366 SX-E uses engine oil for both those functions. This is just another way that MPD’s budget kit simplifies the turbocharger system, not to mention that it’s less taxing on the engine coolant. 2