SCT Performance tunes VMP Tuning’s Gen2 TVS supercharger on a 2015
By Steve Turner
Avid followers of Mustang power adders are quite familiar with the popular Twin Vortices Series supercharger based on Eaton’s rotors. This technology rose to prominence as an upgrade for the Roots supercharged ’07-’12 Shelby GT500s. Eventually it became a mainstream aftermarket upgrade for Mustang GTs, before becoming a factory option on the 2013-2014 GT500s.
Like any good tech install you want to start by disconnecting the battery. Seriously, you’ll need to do that before wiring the intercooler pump and fans, but SCT Performance’s Matt Alderman gets started by removing the front fascia from his 2015 Mustang GT. Be mindful that there are a couple of fasteners hiding behind the splash shield that retain the top corner of the fascia.
One of the popular purveyors of TVS superchargers for Mustangs is Roush Performance. You know from our recent coverage that Roush offers its own TVS kit for the 2015 Mustang GT, which offers a complete supercharger upgrade for the new Mustang GT featuring the popular Gen1 TVS supercharger.
For many people, this option offers plenty of performance and a warranty to go along with it. However, there are always people who want even more performance. Those people are SVTP members and readers. You fine folks know that VMP Tuning partnered with Roush to create its own line of Gen2 2.3-liter TVS superchargers, which offer numerous tweaks designed to maximize flow and efficiency.
“With the 2015 being heavier, the torque of the TVS is more important than ever. However, we don’t leave any horsepower on the table either. Our Gen2 blower is poised to serve the customer that has a daily driver and wants 600 rear-wheel horsepower, to people like my wife, Rebecca Starkey, who want to run 8s in the quarter mile,†Justin added. “We are able to supply a wide range of pulley options for the TVS to run anywhere from 8 to 20-plus psi and make 550 to 900-plus rear-wheel horsepower.â€
Next Matt removed the cold-air intake, disconnected the fuel feed line, and removed the injectors and fuel rails as one piece. He then disconnected the other sensors and hoses, then he could unbolt the manifold and remove it.
Aside from the improvements found in the VMP kit, the packaging constraints of the latest Mustang required numerous tweaks for fitting any TVS supercharger on the new-school Coyote.
“For 2015 the lower intake and blower sit lower in the engine bay to clear the new lower hood line on 15s. The CAI is a little different as the engine bay got narrower up front. The belt system and heat exchanger are the same, which means our eight-rib conversion kit still fits and our triple-pass dual-fan heat exchanger is carryover as well. Technically a 2015 kit will fit an ’11-’14, but an ’11-’14 kit will not fit a ’15 or newer without drop motor mounts.â€
Installing it is one thing, but with any modern car there are other mountains to climb. We didn’t see an early onslaught of insanely supercharged S550s that we might have expected, because tuning the latest Mustangs has been a challenge. This is largely due to a new software strategy inside the new TriCor PCM.
In anticipation of the intercooled lower intake, Matt loosened and adjusted the knock sensors toward the outside to make remove for the deeper intake.
“The best way to put it, tuning the 2015 Mustang GT is similar but different. Ford switched to a Continental computer, and on the surface, many of the tables are the same, but some of the ways they are implemented has changed,†Justin explained.
Fortunately, Roush Performance provides a calibration with its TVS supercharger kits for the 2015 Mustang GT. It makes a TVS kit a worry-free bolt-on. However, this calibration is meant to serve the as-delivered Roush kit, not the higher output VMP system. Such a system calls for custom tuning, which is where SCT Performance comes in.
Before moving on, Matt taped off the cylinder heads’ intake ports to keep out any stray debris from the upcoming aluminum surgery.
Fortunately, we had the opportunity to follow the installation of a VMP Stage 2 TVS supercharger kit (PN STAGE250GEN2; $6,999) on Matt Alderman’s 1,200-mile GT. This kit includes optional upgrades like a VMP TwinJet 67mm throttle body, a twin-fan/triple-pass heat exchanger. Students of the sport know that Matt is the head calibrator at SCT Performance, so he was able to dial in the combination for maximum power.
“When first starting this project I had a lot of obstacles to overcome. The main one was the throttle body,†Matt explained. “In 2015 Ford changed the electronics on the stock throttle body and therefore when changing to the previous year the are many parameters that needed to be found and tested.â€
As you will see, a 2015 5.0, a VMP Gen2 TVS, and Matt’s tuning makes for a potent combo…
The lower-profile manifold for the 2015 Mustang requires a bit of additional modification. This boss on the block must be trimmed down to clear the intake. Using a grinder, or an air saw like this one employed by VMP Tuning’s Justin Starkey, to make a uniform cut. If the cut isn’t clean, the intake might not properly seat on the cylinder heads.If you’ve been around TVS installations on 2011-2014 Coyotes, you are familiar with these modifications to the timing cover. These bosses must be trimmed down to allow the idler bracket to mount flush to the timing cover and cylinder head. Follow the instructions and take your time.After trimming the block and timing cover, then cleaning out the shavings with a shop vacuum, the path is cleared for the lower intake manifold. Matt lowers the intercooled lower into place, taking care to ensure there are no wires or hoses between the mating surfaces of the intake and heads.You can either gap-down the stock spark plugs for boost or you can choose to add a set of optional Brisk Iridium plugs to your kit. They come pre-gapped at .0035-inch, but you can gap them as small as .0026-inch if you plan on installing the smaller pulleys in the VMP array to increase boost.To make room for the supercharger inlet, it is necessary to trim the K-brace that runs from the cowl to the shock towers. Mark the brace along the edge of the cowl panel, then cut the brace and file down the edge. You can do so on the car if you like, or you could mark the brace and remove it for cutting. Either way, you’ll want to file the edge down and paint the exposed metal.With the intake in place, Matt and Justin joined forces to install the coolant hoses and fuel rails fitted with the new 47 lb/hr injectors. Matt tightened the manifold in a crisscross pattern before torquing them to 8 lb-ft.Those timing cover mods allow for the installation of this bracket, which hosts two idler pulleys for the belt. The bracket installs using a mixture of new and re-used hardware, so take a close look at the instructions before you bolt it down for good.Before setting the supercharger in place you will need to install the necessary vacuum lines, including the revamped brake booster vacuum and aspirator hoses. These mods are covered in detailed in the instruction manual. Here Matt swaps the EVAP solenoid from the factory intake to the supercharger using the spacers supplied in the kit.With the necessary vacuum lines and harness extensions laid out, Matt seats the VMP Gen2 TVS supercharger on top of the Roush intercooled lower manifold. Because of its one-piece inlet, the VMP Gen2 doesn’t use the fastener under the inlet. So, Matt hand tightened the nine supplied fasteners using the sequence show in the instructions. He then torqued them to 18 lb-ft.After installing the accessory drive belt by following the diagram in the instructions, Matt completed the re-engineering of the FEAD by installing the bracket that holds the spring-loaded tensioner.Matt chose the Stage 2 VMP kit, but added the optional VMP TwinJet 67mm throttle body. (The bigger throttle body, larger injectors, and a VMP fuel pump booster are standard on the Stage 3 kit.) These beauties provide a nice balance of airflow and driveability. Of course, make sure you install the supplied O-ring on the inlet before you bolt down the new throttle body.Eventually VMP will over its own induction system, but for now the company is including the traditional Roush inlet tube, mass air housing, and airbox. Before installing this system, Matt swaps over the factory mass air sensor into the Roush housing.The VMP Gen2 Stage2 kit not only includes the VMP TVS and TwinJet throttle body, but it offers a significant heat exchanger in the form of a twin-fan heat exchanger. Not only is this heat exchanger massive, but its twin SPAL fans also provide a steady supply of cooling air. Here Matt slides the unit into place and bolts it to the bumper using the supplied grommets and fasteners.This bracket provides a mounting for the intercooler coolant pump. In order to gain clearance for it, Matt flipped the factory horn bracket upside down and re-oriented the harness.Because of its inclusion of the Afco heat exchanger, the VMP kit uses the 2011-2014 Coyote-style heat exchanger hoses, one of which requires this short extension. Matt plumbed the hoses from the manifold to the heat exchanger, intercooler pump, and coolant reservoir.To power the intercooler coolant pump and heat exchanger fans it is necessary to pick up power at the factory fuse box. The included harness is already pre-wired with all the necessary connectors and fittings.Matt used the core support to pick up a ground and mount the two relays, one for the fans and one for the coolant pump.Wrapping up the install, Matt bolted on the intercooler coolant reservoir, plumbed the remaining hoses, and filled the system with coolant. Then we were ready to run on the dyno. The VMP Tuning kit looks factory atop the Coyote in Matt’s GT, but it takes the car far beyond the factory level of performance.Before putting the fascia back on, Matt opted to remove the factory upper and lower grilles to allow for the installation of Lethal Performance’s grille deletes. Numerous factory tabs retain the grilles, so it helps to hold down several of the tabs with individual flat-blade screwdrivers so you can free large sections of the grille at one time.Matt’s GT looks sick with the Lethal grille deletes installed, and as we know with installing an open grille on earlier Mustangs, the improved airflow afforded by this arrangement will reduced coolant temps. That’s handy with an air-to-water intercooler system employed by the VMP TVS kit. Later, Matt blacked-out the heat exchanger and radiator with Eastwood’s radiator paint for an even more sinister look.While Matt started out with the largest pulley VMP offers, which measures 85mm. Thanks to Matt’s ability to custom tune the car via SCT software and an X4 handheld tuner, he can swap on smaller pulleys and add even more power in the future.Likewise, Matt’s custom tuning allowed for swapping out the standard throttle body—which is just a stock GT500 throttle body—for one of VMP Tuning TwinJet 67mm beauties. Even on the base kit, installing this big unit is good for another pound of boost, and without re-calibrating the PCM, that extra boost might lead to knock.Testing and tuning, the car hit the dyno at SCT Performance. Head calibrator Matt Alderman created a calibration for the VMP Gen2 TVS-supercharged 2015 Mustang GT. The core of this calibration will become a value file, which SCT tuning customers can use as the basis for a custom calibration.Matt created a custom tune file that not only allowed the new Mustang’s TriCor PCM to work with an oval-bore throttle body, but to flourish with the addition of the Gen2 TVS supercharger. “I went and adjusted the Ti-VCT at various points to work better with the new blower. I renormalized and adjusted the torque and inverse tables,†Matt said. “When having valve events forced I was able to better populate the spark table for that valve event. I did some speed density work as well.â€With the addition of the VMP system and the custom SCT calibration, Matt’s GT picked up impressive peak-to-peak gains of 196.79 horsepower and 143.67 lb-ft of torque at the wheels. More impressive is that result is on 93-octane pump gas with VMP’s largest supercharger pulley installed. There is definitely more on the table with increased boost and octane.When we can, we also like to take a look at a sampling of the data in chart form. Often this reveals some of those under-the-curve gains that might otherwise go un-noticed. In this case, the gains are so significant across the entire curve that it’s simply impressive. The torque gains are in the triple digits from the jump, and the power moves into the three-digit range from 4,000 rpm on up. Keep in mind that these are gains over an already healthy naturally aspirated combo highlighted by a JLT cold air intake, Kooks long-tube headers, and Matt’s SCT calibration.
