KJ Jones
December 31, 2013
Photos By: KJ Jones

It appears we're now officially entering a time when finding bone-stock Fox Mustangs to modify is a challenge. Seriously, stock '79-'93s are no longer in abundance. Of course, this progressive drought gives us good reason for concern.

However, while the Fox hunt becomes more challenging, we're thankfully seeing a steady rise in the number of stock-as-a-rock Ponies from the next wave—'96-'04 4.6-liter Mustang GTs. Yes, it seems the closer we get to finally experiencing the highly anticipated '15 'Stangs, the more we're seeing SN-95 and New Edge rides appear on our radar, with medium-to-high- mileage Two-Valve powerplants that are perfect for upgrades.

With affordability being the buzz theme for most pre-Coyote Mustang projects these days, many of our recent test efforts have been focused on various groups of the basic air-induction and exhaust hardware for fuel-injected, '86-'10 Ponies; evaluating their installation simplicity and the impact they make on relatively untouched 'Stangs.

As we've said many times, bolting a power adder onto any of the engines that motivate the 'Stangs we cover is a sure-fire way to increase their performance. However, this direct route to big steam often leaves a lot to be desired when it comes to the financial side of things.

While a 'Stang's horsepower potentially can be doubled once a blower, turbo, or nitrous is added, an important caveat to note is that exorbitant gains typically come only after some serious coin is spent. With that notion in mind, while we certainly dig the process of making fantastic steam, we also enjoy presenting mod projects that won't flatten your wallet.

BBK Performance offers all of the parts that make up basic and intermediate bolt-on performance systems for late-model 'Stangs. While underdrive pulleys, CAIs, throttle bodies, after-cat exhaust, and X- or H-shaped crossovers constitute the simple stuff, the next level of “basic” typically includes taking exhaust upgrades a bit further by installing headers, which is exactly our plan is for this project.

For this Two-Valve edition of entry-level-parts testing, we're adding long-tubes to the standard group of basics that make up a BBK bolt-on package. Chris Goodner's stock, 67,000-mile '01 Bullitt is our test bed, as it's a perfect example of the older EFI Mustangs that are now becoming more prevalent on today's modifyication scene. We really have to thank GTR High Performance's Ricardo Topete for finding our test Mustang, and technician Eddie Zapata for handling the bolt-on duties. Presenting long-tube headers to this equation brings a need for SCT PCM tuning, which Chris Jones of Blow-By Racing handles for GTR via the Internet.

These photos and captions detail the operation, which was done in reverse order (headers and tuning first, then pulleys, throttle body and CAI as a threesome) to accommodate the additional time necessary for installing long-tubes. The top-side parts are all DIY-friendly to 'Stangbangers with mechanic skills and a driveway to work in. The headers, on the other hand, are best left for Mustang pros like Eddie, who have the tools and facilities (twin-post hoist) necessary for the heavier job.

GTR High Performance tech Eddie Zapata lifts a BBK long-tube header into position on the 4.6-liter Two-Valve bullet in Chris Goodner’s ’01 Bullitt.
With only 67,000 original miles on the odometer, Chris’ recently purchased Pony is a great example of the type of ’Stangs that today are readily available—affordable, bone-stock, good-condition, and perfect for modification.
We usually begin bolt-on efforts like this by swapping the factory air-induction hardware with aftermarket pieces first, and then finish up with exhaust upgrades that typically feature simple after-cat or X-shaped crossover systems. However, with long-tube-header installation being a lot more labor intensive, we chose to make the exhaust mods first. After performing prerequisite tasks such as disconnecting the negative battery cable and raising the car with a twin-post hoist, Eddie removed the factory exhaust manifolds, and then thoroughly cleaned the ports in preparation for the new headers.
Here is a look at the major difference between the stock, cast-iron intake manifolds and BBK’s long-tube headers. Unlike manifolds, headers feature individual tubes for each exhaust port, which all are merged into one common point. This design promotes optimum cylinder scavenging and exhaust flow, which helps promote increased horsepower and torque in Two-Valve engines.
The driver-side BBK header is equipped with a bung for connecting the tube that links it with the EGR Valve (the valve that recirculates exhaust gas into the engine via the intake manifold to help cool the air/fuel mixture and lower the possibility of detonation). However, we deleted the EGR by cutting off each end the tube and modifying them—by crushing and welding—to become a plug (for the valve) and a cap (for the bung on the header).
The driver-side BBK header is equipped with a bung for connecting the tube that links it with the EGR Valve (the valve that recirculates exhaust gas into the engine via the intake manifold to help cool the air/fuel mixture and lower the possibility of detonation). However, we deleted the EGR by cutting off each end the tube and modifying them—by crushing and welding—to become a plug (for the valve) and a cap (for the bung on the header).
Once installed, the headers are a clean fit down below, free of any conflict with the K-member, A-arms, or especially the Mustang’s five-speed transmission.
And on the topside, fitment is equally as good, as there’s no conflict with framerails or steering gear in any way.
And on the topside, fitment is equally as good, as there’s no conflict with framerails or steering gear in any way.
Do you recall us saying the Two-Valve header swap is a labor-intensive process? Bolting the tubes up to the cylinder head literally requires five 13mm wrenches (the four shown, and one that Eddie is using) of different lengths.
The Bullitt’s factory exhaust system was removed at our project’s outset. GTR has an impressive stack of these cast-off exhaust pieces, which typically are done away with in basic bolt-on efforts, regardless of whether long-tubes are installed.
The long-tube installation mandates using a BBK 2.5-inch, short, X-shaped crossover tube (PN 1635; $179.99).

On The Dyno

Our latest work with basic bolt-ons for 4.6-liter Mustang engines proves there's a wealth of horsepower holed up in a stock Two-Valve's exhaust.

GTR High Performance's Ricardo Topete and Chris Jones of Blow-By Racing collaborated on the dyno and laptop keyboards to coax approximately 20 additional horses from the stock Two-Valve engine in Chris Goodner's '01 Bullitt after exchanging the ‘Stang's factory exhaust manifolds for a set of BBK Performance long-tube headers, and remapping the Pony's PCM with SCT tuning software.

GTR High Performance has a great cooperative arrangement for PCM tuning, with Chris Jones of Blow-By Racing in Boca Raton, Florida. Through the technology of the Internet (for transferring data and calibration files) and SCT tuning software, Chris modified our ‘Stang’s fuel and timing tables after the headers were installed. Once maximum power and a safe air/fuel ratio was achieved with the exhaust, only a few minor changes were necessary after the remaining bolt-ons were installed.

Taking a slightly different approach with the remaining bolt-ons, the BBK Black Out cold-air-intake system, 65mm throttle body, and three-piece underdrive pulleys were examined as a group instead of in our standard individual manner, and opening up the intake produced almost the exact amounts of rear-wheel horsepower and torque that we anticipated from the collective package.

Our dyno sequencing also was a bit different for this project. While we typically baseline test a stock ‘Stang on the Dynojet chassis dyno and then evaluate horsepower/torque changes after each part is added, only two post-baseline runs were made for this effort—to adjust the PCM calibration after headers were added, and to determine what differences the remaining bolt-ons (CAI, throttle body, and pulleys) made as a group.

Baseline
Headers
Bolt-Ons
Difference
RPM Power Torque Power Torque Power Torque Power Torque
2,500 119.14 250.29 121.79 255.87 122.77 257.92 3.63 7.63
2,600 124.78 252.05 128.37 259.30 129.39 261.37 4.61 9.32
2,700 130.11 253.09 134.89 262.40 136.45 265.42 6.34 12.33
2,800 134.32 251.95 139.98 262.56 141.98 266.32 7.66 14.37
2,900 138.46 250.75 145.02 262.64 147.24 266.67 8.78 15.92
3,000 142.54 249.55 150.25 263.04 153.55 268.82 11.01 19.27
3,100 147.51 249.90 156.69 265.47 160.94 272.67 13.43 22.77
3,200 154.67 253.85 164.93 270.69 170.32 279.53 15.65 25.68
3,300 162.23 258.20 173.76 276.54 179.82 286.18 17.59 27.98
3,400 169.62 262.01 181.67 280.63 187.63 289.84 18.01 27.83
3,500 174.98 262.58 187.94 282.03 193.93 291.01 18.95 28.43
3,600 179.87 262.42 193.42 282.18 200.34 292.27 20.47 29.85
3,700 186.18 264.28 199.90 283.75 207.40 294.40 21.22 30.12
3,800 191.97 265.33 206.61 285.57 214.53 296.51 22.56 31.18
3,900 198.43 267.22 213.64 287.70 220.81 297.37 22.38 30.15
4,000 204.39 268.37 220.27 289.22 227.31 298.46 22.92 30.09
4,100 211.14 270.46 227.18 291.02 233.12 298.63 21.98 28.17
4,200 216.32 270.50 231.72 289.77 238.69 298.49 22.37 27.99
4,300 219.00 267.49 234.58 286.53 243.97 297.99 24.97 30.50
4,400 221.44 264.32 237.74 283.78 247.39 295.30 25.95 30.98
4,500 224.96 262.56 240.71 280.94 251.21 293.20 26.25 30.64
4,600 227.69 259.97 244.16 278.77 253.22 289.13 25.53 29.16
4,700 228.95 255.85 247.28 276.33 255.39 285.39 26.44 29.54
4,800 232.18 254.05 249.61 273.12 257.78 282.06 25.60 28.01
4,900 231.90 248.57 251.72 269.81 259.30 277.94 27.40 29.37
5,000 232.57 244.30 252.05 264.76 260.62 273.76 28.05 29.46
5,100 232.45 239.39 252.63 260.17 260.83 268.61 28.38 29.22
5,200 231.08 233.40 250.23 252.74 260.86 263.47 29.78 30.07
5,300 229.64 227.57 250.02 247.77 260.47 258.12 30.83 30.55
5,400 226.74 220.53 249.48 242.65 259.72 252.61 32.98 32.08
5,500 225.77 215.59 247.41 236.26 259.31 247.63 33.54 32.04