With the VMP blower supplying us with a significant amount of power, we knew that the factory fuel system would need a little pick-me-up. JMS Chip & Performance supplied us with a PowerMax fuel pump voltage booster/regulator (PN PM-1000, $329). Ford equipped the '03-'04 Cobras with a dual pump assembly set to run on a constant 12 volts when in use, but we still needed to increase fuel output with the new TVS installed. The booster/regulator from JMS allowed us to still utilize the factory pumps, but increase the voltage from 12 to 18 volts. With it installed, the minimum amount of voltage the pumps are receiving is now 14, and with the increase in voltage, the factory pumps can now deliver more fuel at higher pressure.
The PowerMax will work on any Mustang and is designed to increase the stock fuel pump's capabilities by over 80 percent. Included in the JMS kit is a remote-mounted voltage control knob and Hobbs switch. The Hobbs switch is activated when it sees a predetermined amount of boost. It is preset at 5 psi, but is user-adjustable from 3 to 7 pounds. We opted to keep the pre-setting, so when the new TVS blower produces 5 pounds of boost, the Hobbs switch activates the booster/regulator and voltage is increased.
The voltage control knob works hand-in-hand with the Hobbs switch and allows the user to set the voltage increase over a specific period of time. There are four settings on the voltage knob--0-, 0.25-, 0.50-, and 0.75-seconds. For our install, we set the voltage to increase over a half a second. What this is doing is avoiding a fuel spike when going to WOT. The pumps are starting at 14 volts and gradually increasing to 18 volts over the half a second time frame. We not only needed a better supply of fuel from the fuel pump, but the fuel injectors as well. We called upon our good friends over at Central Florida Motorsports where they supplied us with a new set of Siemen 60 lb/hr injectors. With the PowerMax and larger injectors, our '03 Cobra now has more than enough fuel to handle the added boost from the TVS.
13a Assembly of the new blower...
13a Assembly of the new blower began by placing the new blower...
13b ...with the intercooler...
13b...with the intercooler onto the factory lower intake.
14 Due to having one of the...
14 Due to having one of the first prototype designs, we were required to machine part of the front-left blower intake bolt. VMP has since redesigned and supplied a new bolt to fix the fitment issue.
15 To supply more fuel to...
15 To supply more fuel to our big power plant, we installed Siemens 60-lb/hr injectors onto the factory fuel rails.
16 Installation of the intercooler...
16 Installation of the intercooler water tube housing assembly was inserted into the factory intercooler and attached to the new blower.
17 With all the new and factory...
17 With all the new and factory hardware replaced or reused, we were finally on our way to installing the new TVS blower. (Editors note: It's beneficial to have a second person to help with reinstalling the new blower, intercooler, and lower intake as one assembly into the engine valley.)
18 With the TVS kit requiring...
18 With the TVS kit requiring the EGR to be deleted, we had to delete the unneeded hoses and placed the vacuum/boost attachments where needed. VMP gave us one of its EGR delete caps (PN W705609-S430).
19 We then installed the...
19 We then installed the 3.2-inch pulley (PN CTVS32, $89.99) that VMP supplied onto the new blower hub assembly.
20 SCT supplied us with one...
20 SCT supplied us with one of its 90mm BA-2600 mass air meters (PN BA2600, $249.95). Since we will be beyond the operating capabilities of the stock MAF, an aftermarket piece like this is necessary. This one supports up to 700 rwhp on a positive displacement application.
21 To complement our increase...
21 To complement our increase in airflow, Accufab sent us one of its monoblade throttle-bodies (PN SKU 10F-1726-xx, $325). The stock throttle-body posed as a restriction in airflow, so we opted to use its product in our testing, along with VMP’s complementing inlet elbow.
22 Here is a shot of the...
22 Here is a shot of the finished product. What you see here includes the TVS blower, 3.2-inch pulley, SCT mass air meter, Accufab throttle-body, and JLT ram-air intake.
23 Our bolt-on combination...
23 Our bolt-on combination yielded 450 rwhp and 459 lb-ft of torque. With the new TVS blower installed, we cranked out 542 rwhp and 499-lb-ft--a 92-rwhp and 40 lb-ft gain.
24 Our final numbers were...
24 Our final numbers were 578 rwhp and 543 lb-ft of torque with the 2.8-inch pulley. We were very pleased with the final results yielding a 214 rwhp and 201 lb-ft of torque gain over stock. We powered through the clutch after switching to the 2.6-inch pulley, ending our test session. We feel the 600 rwhp mark would be easily acheivable with a clutch swap and some race gas.
25 Here you can see the Hobbs...
25 Here you can see the Hobbs switch supplied with the Voltage Booster kit. The Hobbs switch is preset to close when it sees 5 psi of boost. However it is adjustable from 3 to 7 psi.
26 The PowerMax voltage booster/regulator...
26 The PowerMax voltage booster/regulator is designed to increase output of any fuel pump. The unit must be mounted inside either the vehicles cabin or in the trunk. We choose to mount it in the trunk where it would be hidden.
Our baseline dyno pull pumped out 381 rwhp and 357 lb-ft of torque. After we added the JLT ram-air intake and tune, the Cobra laid down an impressive 419 rwhp and 398 lb-ft of torque. Finally, with the 2.75-inch pulley, we hit the rollers one more time and came out with 450 rwhp and 459 lb-ft. This netted us with a 69 rwhp and 102 lb-ft gain from where we started.