5.0 Mustang & Super Fords
BBK Full-Length Headers Install - Tube Amplification
Turning up the power on a blown 5.0 with the addition of long-tube headers
Horse Sense: Obviously tuning is the central offering from an outfit named VMP Tuning, but main man Justin Starkey has become closely associated with getting the most out of Fords with the 2.3-liter TVS supercharger. This is more true now than ever, as VMP offers its own TVS supercharger with a small pulley and high-flow inlet pre-installed.
Last we left VMP Tuning’s ’11 Mustang GT, Justin Starkey had transformed his wife’s bolt-on car into a legitimate 10-second street car. This was accomplished with the mere addition of a Roushcharger supercharger and a flash of Justin’s tuning mastery. With Rebecca behind the wheel, the car nudged into the 10-second zone with a 10.98 at 127 mph.
“What we did with an out-of-the-box Roush 5.0-liter supercharger kit will not be too hard for the average Joe to duplicate, but it was a new application and there were a few hurdles to get past. Once I started to dial in the engine and did some auto trans tuning, and Rebecca got more track experience with the blower, the combo all came together,” Justin explained. “The result was a 10.98 pass a week after we put the Roush kit on. At the time the car only had drag radials on factory 18s, J&M lower control arms, a PST driveshaft, VMP custom tuning, and an out-of-the-box Roush 2.3-liter TVS kit. The kind of power we are making with these 5.0s is Terminator and GT500 territory.”
For a car running through a cat-less stock exhaust, this was an impressive feat. However, once a mountain is conquered, there is always another mountain. Since that time, Justin has tirelessly tweaked the car’s combination for more performance. Working with SCT software and hardware and moving to an 85mm pulley (down from 90mm) were the next moves. With some favorable weather at the NMRA finals in Bowling Green, Kentucky, and an FRPP Cobra Jet throttle body installed, Rebecca ran a 10.61 at 130.6 mph. That was still rocking the stock wheels and suspension.
“When we went to the Bowling Green NMRA race and Rebecca pulled off the first 10.6s. The big change was a 85mm supercharger pulley and accompanying fine tuning,” Justin added. “We are still running the restrictive enclosed airbox so most of the gain was in low-end torque, around 30 lb-ft, and a little top end horsepower. This improved the 60-foot a bit while still on 18-inch 275 Mickey Thompson drag radials.”
Next up were a move to lighter Weld Racing wheels and relocated lower control arms to improve traction and weight transfer. Under the hood, Justin finally settled on the 72mm pulley, putting boost plateau maximum at around 11 psi as muted by the restriction of the sealed airbox. Justin decided to stop there to keep the boost in a range that the nearly maxed-out factory fuel system could handle.
About this time, we came along with the idea to throw some BBK long-tube headers into the mix to see what uncorking the exhaust side of the equation would accomplish. Justin had already removed the cats for racing, but Rebecca’s ebony Pony still sported an otherwise stock exhaust system. After getting the car up and running with the headers, we thought we’d hit a wall until Justin discovered some tuning necessities when adding long-tube headers.
“The long-tube header install did not require any air/fuel changes (or cause any), but the key to extracting power from any Coyote combination is getting the TI-VCT right,” Justin hinted. “We are making 640 rwhp through an auto transmission; the guys with larger blowers and manuals are making more at the wheels, but crank horsepower is similar, around 800 hp. We intentionally run the factory enclosed airbox to limit boost on the top end for fuel system and engine durability reasons.
“We have not even begun to push the Roush 2.3-liter TVS kit hard. The TVS has produced over 800 rwhp on my Shelby GT500. There is plenty left in the 2.3-liter blower, at this point we are just stepping lightly around the stock engine/trans/fuel system. I believe the Roush kit could easily go to 700-750 rwhp on a stock engine with fuel, though it would be on borrowed time.”
In the end, the combination described here resulted in a stunning 10.00 at 138 mph with a 1.5-second 60-foot time. Keep in mind that this car has a stock engine. So despite its most obvious bolt-on—the blower—it is still a new Mustang with a handful of bolt-on parts. These are good times indeed, and Rebecca’s project is far from complete.
“I’m turned on by the fact that we are going to see a bunch of factory hot-rod 5.0-liter parts. The 5.0 in the F-150 is going to be lower compression than the Mustang version, which is good for boost. The Roush kit will essentially bolt right onto an F-150. Then we’ve got the Boss with its factory forged parts,” Justin said. “Whether we can draw from this parts bin or just use aftermarket parts is still being determined. The stock auto trans and stock converter is almost more of a durability concern than the engine, but solutions are becoming available for that, too. We plan to eventually build an engine to handle 20 pounds of boost. However, to run fast a built motor is not as much of a necessity as everyone first thought. The factory 11:1 compression ratio is boost-friendly, even on pump gas.” 5.0
On The Dyno
Though boost actually tailed off a bit due to the reduction in backpressure, the addition of the BBK headers definitely picked up the power of Rebecca’s Roushcharged ’11 GT. The gains were particularly strong in the midrange, where the ’Stang picked up peaks of 19.22 horsepower and 22.63 lb-ft of torque. Since our testing, Justin has since stepped the blower down to a 69mm pulley, resulting in a whopping 670 hp and 610 lb-ft at the Mickeys. This car is currently producing the power of a bolt-on GT500. The Coyote era truly is a big reset for our bolt-on expectations.
|Stock Manifolds||BBK Long-Tubes||Difference|