How to Build a Budget Terminator - Cheap Snake Pt. 2: Blower Install

There are times when deciding on the content (feature articles, tech reports, and so on) for the pages of 5.0 Mustang & Super Fords is an extremely challenging task, and there's a very good reason why this is so. At this juncture, there are simply a lot of different late-model Mustangs.

Of the five platforms that have been introduced over Mustang's 50 years, four groups are directly in our wheelhouse ('79-'93, '94-'04, '05-'10, and '11-'15). In a 10-year subset of that overall timeframe is a series of special-edition Ponies called SVT Cobras, which really aren't discussed as much as other V-8 Mustangs as far as technical changes and improvements.

As Cobras go, the factory-supercharged models of '03-'04 are considered the baddest 'Stangs of the series, which had only been naturally aspirated prior to '03. With more than 350 horses at the feet from the factory, Terminators—SVT's internal handle for the cars—reigned supreme in the overall late-model Mustang hierarchy until the advent of the Shelby GT500 in 2006. The subject of modifying '03-'04 Cobra Mustangs for increased performance has been well covered over the years. At this point, the tried-and-true templates for increasing steam haven't really changed.

The initial jump to more horses is made by installing a variety of bolt-on parts that focus on optimizing intake and exhaust airflow, and slightly raising boost output (CAI, throttle body and plenum, MAF, an X-shaped crossover tube and mufflers, and a smaller blower pulley). Once you're acclimated to the gains and the need for more becomes too great, a power-adder change of some sort is the standard next move. We're talking about an upgrade that typically involves doing away with a 'Snake's factory Eaton supercharger, and replacing it with a twin-screw or TVS unit that displaces more air volume, and ultimately makes more boost.

Tedd’s mission to buy and upgrade a Terminator on a small budget got off to a great start when he scored this fantastically mint (one owner and babied) black ’03 for only $22 grand. The car was listed on Craigslist.com and was located not too far from where Tedd lived.

Eddie Zapata (right), Pedro Pasoldan (center), and Ricardo Topete of GTR High Performance lay a Whipple 2.3L supercharger down on the Four-Valve engine in Tedd Mason’s ’03 Cobra. The previously owned blower, scored through an online deal with a fellow Cobra owner, is the icing on Tedd’s low-investment-upgrades cake.

Here is the showpiece for our last segment of Tedd’s project—a Gen 1 Whipple 2.3L twin-screw supercharger that Tedd found by faithfully scanning the Classifieds section at www.svtperformance.com. The complete system (and a few extra bits that were thrown in the deal) was had for only $2,200.

We've been following the modification efforts of Tedd Mason, a Southern California Cobra owner, who is taking such steps toward achieving big steam with cost serving as a major guideline for his project.

As we detailed in our first report on Project Cheap Snake (July '14, p. 64), Tedd was able to beef up his '03 Terminator with just the basic bolt-ons, which he acquired through shrewd, online parts deals with fellow Cobra owners. As we explained, Tedd's ultimate goal is to hopefully increase his Snake's power output to the 600-horse range, by way of addition of a replacement supercharger procured by the same frugal means.

In this closing report, we return to GTR High Performance in Rancho Cucamonga, California, to catch up with the latest details of Tedd's mission. Check out our photos and captions to learn more about Tedd's low-buck, 2.3L blower score, and the difference bigger boost makes on his personalized SVT Pony.

01. At the project’s outset, the 4.6L 32-valve bullet in Tedd’s Cobra was completely stock with the exception of Lethal Performance coil covers, and a Bassani catted X-pipe and Flowmaster mufflers. In our first report, Tedd installed a slew of popular Cobra bolt-ons that were all purchased at minimal cost (through shopping and horse trading with fellow Terminator fans on Mustang forums). These increased the stocker’s power from 404.65 to 430.07 for a total cost of only $1,118.

02. Immediately after the bolt-on session, the team at GTR pulled the transmission and exhaust, replacing the stock pieces with new hardware from McLeod Racing (RXT twin-disc clutch) and long-tube headers from BBK Performance. A return to the dyno wasn’t immediate, as Tedd had to put roughly 500 miles on the new clutch before we could evaluate the car’s performance with the long-tubes.

03. Several support pieces for the blower swap were necessary, and Tedd stayed true to his low-dollar plan with each purchase. Pieces from SCT (X2 programmer, Big Air 3000 MAF) and Metco (idler pulley set) were all purchased from online connections. A set of new gaskets was the only full-price setback because a Ford dealer was the go-to source for those items, which are highly recommended for a project like this. As we explained in the first report, Tedd stresses the importance of communicating with online sellers and asking a lot of detailed questions about parts you’re considering. “Doing this really helped weed out the stuff that wasn’t good or complete, as well as good sellers from bad,” he says.

04. Ricardo and Eddie go about removing the Cobra’s stock Eaton M112 supercharger. While the blower produced just over 6 psi of boost with the factory pulley on Tedd’s ride when the bolt-ons were installed, the Roots-style unit is capable of generating 8 psi.

05. With the stock blower removed, Eddie extracts the OEM intercooler, which is reused with the new 2.3L ’charger.

06. Because the new supercharger is physically larger (dimensionally) than the M112, a slight modification to the stock belt-tensioner is necessary. Cutting material (a small stopper) from the tensioner will increase its swing radius, and ensure the belt remains tight under boost conditions.

07. Ricardo cleans and prepares the cylinder heads for placement of the upgrade supercharger. While residual gasket material isn’t an issue with modular engines, it’s still important to ensure there is no debris around the intake ports or any of the head-to-manifold seal areas. A set of new spark plugs (PN NGK TR6/4177) was also installed at this time.

On the Dyno

Please take a close look at the dyno chart, graph, and breakdown of Tedd Mason's expenses. They show how much Tedd Mason's '03 Cobra was improved in both phases of his budget-conscious upgrade effort.

Check out our July '14 issue (“Cheap Snake”) or find the article on www.mustang-360.com for a refresher on the steps Tedd took for finding, purchasing, and installing the first round of upgrades on his Cobra. You will also find the baseline and post-bolt-ons (Bolt column) power-and-torque data from the initial stage.

While the second level of the project is highlighted by replacing the Cobra's stock supercharger, its first data point comes from dyno-testing with BBK's long-tube headers and H-pipe installed. The components actually were added immediately after the first bolt-on session (along with a McLeod Racing RXT twin-disc clutch system). However, testing on the Dynojet chassis dyno could not be performed until Tedd had driven a few hundred miles to break in the clutch.

Obviously, adding a 2.3L twin-screw supercharger made the biggest impact on Tedd's 'Stang, taking rear-wheel horsepower and torque well beyond the 500/500 that Tedd hoped his upgrades would produce using 91-octane fuel. To make such performance gains possible, GTR High Performance turned to Bob Kurgan for assistance with the Snake's PCM calibration.

While proper fueling is critical whenever forced-air increases are made, spark is equally important. In tuning Tedd's ride, Bob focused on making small timing increases—starting with 16 degrees, and eventually locking in 18 degrees of timing advance—to achieve 600 horsepower at the feet, with a very safe 11.6 air/fuel ratio. (A glory pull that yielded almost 610 horses was made after nearly an hour cool down and with 20 degrees of timing.)

Below is a final version of Tedd's detailed ledger of his project's expenses (parts/labor prices), and how those amounts relate to the increased horsepower and torque. One of the things that makes his project so compelling and relatable is the fact that all of the performance improvement came by way of adhering to a tight budget and making good choices when parts—new or used—were purchased. It's something that's easy enough for anyone to do.

On the Dyno cont.

GTR High Performance works very closely with Bob Kurgan of Kurgan Motorsports when developing custom PCM calibrations for upgraded ’Stangs that require changes in the computer’s air, fuel, and timing strategies. Bob uses SCT’s Advantage III software to create a new file for Tedd’s car, which Ricardo downloads into the shop’s workstation and then transfers into an X2 handheld programmer for porting into the Cobra’s processor.

08. Here is a comparative look at the original Eaton M112 supercharger that Ford installed on its ’03-’04 Cobra Mustangs and the 2.3L twin-screw–style blower that we’re installing. The 2.3’s larger air- intake capacity, bigger rotors, and “screw” method of forcing air into the engine are the major differences between the two, as are their discharge areas.

09. Before installing the new blower, Ricardo bolts the OEM intercooler to the 2.3 and adds a bead of silicone around the entire perimeter of the area where the ’cooler is placed. This ensures a tight seal and prevents boost or coolant leaks.

10. While a supercharged Cobra’s factory-installed 39-lb/hr injectors (right) are capable of supporting a little more than 450 rear-wheel horsepower, stepping up to 60-lb/hr squirters is necessary when the stock blower is being exchanged for a 2.3L unit.

11. With the low-budget blower in place, Ricardo gives the pulley a few turns to confirm the rotors spin freely and there are no other operating issues.

12. Eddie positions the throttle body, JLT air-intake tube, and SCT BA3000 mass-air, which were carried over from the project’s initial bolt-on package.

13. We’re going with a 3-inch-diameter pulley on the supercharger. This is considerably smaller than the stock 3.65-inch pulley, and should increase blower speed enough to generate about 16 psi of boost.

14. Adding supercharger oil and a new serpentine belt (a longer belt is required for the new blower), and connecting such ancillary items as throttle/cruise-control cables and such are the final steps in the blower-swap process.

15. With its black finish, the bigger 2.3L ’charger looks sinister atop the 32-valve bullet in Tedd’s Snake.

16. GTR High Performance works very closely with Bob Kurgan of Kurgan Motorsports when developing custom PCM calibrations for upgraded ’Stangs that require changes in the computer’s air, fuel, and timing strategies. Bob uses SCT’s Advantage III software to create a new file for Tedd’s car, which Ricardo downloads into the shop’s workstation and then transfers into an X2 handheld programmer for porting into the Cobra’s processor.

Horse Sense:
By a show of hands, how many of you know that Eaton’s M112 supercharger was not the blower that Ford SVT engineers initially selected for then-new ’03 Cobras? That’s right, an Eaton M90 blower was chosen first. However, when it became clear that the smaller unit could not meet the huge intake-air requirement of Cobra’s 4.6L, 32-valve engine, the call was was made to add the larger blower from SVT’s Lightning pickup truck. The decision resulted in an unheard of 390 horsepower at the flywheel (for a production EFI Mustang), and the rest, as they say, is history.