Michael Johnson Associate Editor
January 1, 2008
The exuberant Darrell Pitts is the owner of our subject '05 Roush Mustang convertible. He outfit his Roush with several bolt-ons prior to Zamboni Speed and Custom adding the Turbonetics single-turbo kit. When he received the Roush after the installation, he was pleased with the newfound power of his droptop. With more than 400 hp to the wheels and bright red paint, we're sure Darrell will become a favorite among the local police. (His buddy Teddy Witherington is at the wheel in this shot.)

Horse Sense: Unlike a supercharger which typically uses a belt from the crankshaft pulley to drive its boost-making ways, a turbocharger uses exhaust air to make power. Since it doesn't use horsepower to make horsepower, it is thought to be a more efficient way of making power when compared to a supercharged application, although it introduces backpressure into the exhaust system.

Forget everything you know about turbocharger kits. We all know the nightmare that came with installing one in the Fox Mustang days. Fitment issues abounded, and the lack of customer service further kept turbochargers at the underground level. Only the most dedicated power fiends made the commitment, because installation, tuning, and troubleshooting took on a whole new personality compared to other power adders. Turbocharger kits were reserved for race cars, such as those of Racin' Jason Betwarda, Gene Deputy, and Wild Bill Devine, to name a few. Those guys had the resources to take a unit and build the necessary tubing and brackets to install it on the car.

These days, the turbocharger climate has changed. Sure, there are still fitment shortcomings on Fox cars, but most high-mileage Foxes are so twisted up, even stock parts have a problem fitting at times. On the whole, the turbocharger aftermarket has heard the requests from consumers wanting complete kits that anyone can install and has answered with several systems for late-model Mustang applications, including Fox bodies. When the '05 Mustangs hit the market, everyone and their brother came out with a turbocharger setup for them. That fact may be having a trickle-down effect on the rest of the Mustang market, even though kits really gained a head of steam shortly before the S197 Mustangs turbos hit the streets. With the '05 Mustangs, it seemed turbocharger systems became like injured NFL players-a new one was out every week.

The focus of this report is Turbonetics' new single turbocharger kit ($5,745). Everything needed to install the system is included, something lacking in kits of the past. It features one of Turbonetics' own T4 60-1 turbochargers-perfect for mostly stock '05-and-up Mustang GT applications. Anything bigger would expedite the need for a built short-block. Important support equipment includes a Spearco intercooler, a Raptor blow-off valve, an Evolution wastegate, Denso 39-lb/hr fuel injectors, and an SCT handheld reflash tool. All the tubing in the kit is either polished or black chrome and uses T-bolt or V-band-style clamps. Follow along as we dry our hair to the tune of 400-plus rwhp.

Here are the larger parts contained in the Turbonetics kit, including the T4 60-1 turbocharger, Spearco intercooler, exhaust and intercooler tubing, Evolution wastegate, and Raptor blow-off valve. One of the things we like about the Turbonetics kit is the detailed instructions it features. Each item in the kit has a part number-even the small hardware pieces. Whenever a step calls for adding a part, the part number is present so there's no confusion as to what goes where.

Anytime you have to install an intercooler on a car, you're better off removing the front bumper cover. Thankfully, it's not difficult or time consuming to do on '05-to-current Mustangs. Zamboni Speed and Custom owner Mike Zamboni and lead tech Shawn Finley (left) make it look easy.

It's a good idea to drain the car's cooling system because the upper radiator hose gets replaced, the reservoir is relocated, and the radiator is moved forward ever-so-slightly.

Space is at a premium under the hood of a stock '05-to-current Mustang GT, so a lot of time is spent prepping the engine compartment for a new tenant. Since the turbo is mounted at the front of the engine, computer wires must be moved, fluid lines are adjusted, and other measures are laid out by Turbonetics' instructions to make room for the single-turbo kit. There's considerable room once everything is moved, but you're still left wondering how the turbo and all the requisite plumbing are going to mount.

Per the instructions, Shawn changes the stock fuel injectors for the included Denso 39-lb/hr squirters. If the fuel system is still pressurized, it's a good idea to have a rag to soak up excess fuel when disconnecting the rails and fuel injectors.

Before installing the driver-side injectors, Turbonetics recommends installing the T-fitting into the vacuum line running along the fuel rail. The line has to be cut 911/42 inches from the fuel pressure/MAP sensor, and the T-fitting installs between the two hose sections.

To mount the intercooler, the four inner front bumper support bolts need to be removed. Turbonetics supplies four new bolts, spacers, washers, and nuts to mount the intercooler using the supplied brackets.

One of the first things to do as part of this install is remove the battery and gain access to the heater hoses, which have to be disconnected at the hard lines. Turbonetics includes a section of 5⁄8- and 3⁄4-inch hose. Cut a 2 1⁄2-inch length of each and put them onto its respective heater-hose hard line. The factory hoses are a staggered size, so each cut section must be installed into its corresponding line. Place the corresponding fitting onto each hose, and reinstall the factory heater hoses onto the fittings.

Not only is the turbocharger water cooled, it also uses engine oil as its lifeblood. As with most supercharged applications, a hole must be put in the oil pan for the oil drain hose. Using a 1⁄8-inch drill bit and the supplied tapered center punch, the hole is tapped for an included fitting. Cut a 32-inch length of the 5⁄8 hose and attach it to the fitting. The other end will attach to the turbo.

To put in the oil feed line, locate and remove the oil pressure sensor. Using supplied components, a fitting assembly installs in place of the pressure sensor. The oil pressure sensor and the oil feed line will install into the assembled fitting.

Turbonetics recommends loosening the front sway bar to make working room for installing the turbo-charger assembly and exhaust tubing. Several fluid and electrical lines in the turbocharger area must be wrapped to protect them from the heat generated by the turbocharger and its tubing.

To make even more room for the turbo install, the upper radiator brackets must be drilled for two new holes to move the top of the radiator 3⁄4 inch forward. The factory radiator shroud must also be modified.

The factory H-pipe needs to be modified to accept the turbocharger's exhaust tubing. It has to be cut 2 1⁄2 inches downstream of the catalytic converters. Using factory clamps from farther down the stock exhaust, install the Turbonetics Y-pipe onto the catalytic converter pipes.

The pipe Turbonetics labels "exhaust pipe 2" attaches to the Y-pipe using a V-band clamp. Exhaust pipe 2's bracket also uses a front lower transmission bellhousing bolt to hold it in place. As with most exhaust systems, loosely attach exhaust pipes until the complete assembly is installed, so it can be manipulated to make sure other pipes and tubes will also fit.

The exhaust pipes and tubes use various brackets to keep them stable. This one uses three oil pan bolts at the bottom of the engine block. The other attaches to the A/C compressor studs, held in place by two nuts.

At this point, it's time to get out the heat wrap for the downpipe and the exhaust up-pipe. Turbonetics supplies safety wire to secure the heat wrap on the pipes.

The aforementioned A/C compressor bracket holds downpipe 1 in place. Turbonetics recommends fitting a V-band clamp onto downpipe 1 prior to the fitting of downpipe 2.

The up-pipe (facing up in this image) uses this support bracket for stability. The bracket attaches to an engine stud using the factory nut. The up-pipe attaches to exhaust pipe 2 (attached to the Y-pipe) and uses the oil pan bracket for stability. The up-pipe is also where the turbocharger mounts, hence the flange.

The Evo wastegate installs in the up-pipe leading to the turbocharger. A wastegate regulates the amount of air ingested by the turbocharger. Without a wastegate, the turbocharger would feed ever-increasing boost into an engine, which is especially bad for stock engines that can only handle up to 10 pounds of boost. For Darrell's car, the Zamboni crew regulated the wastegate to allow 7 pounds of boost to the engine. The other end of the wastegate dump tube is routed to downpipe 2.

Here's a good look at downpipe 2, which Shawn is attaching with the help of the passenger-side lower bellhousing bolt. Downpipe 2 attaches to downpipe 1 at the front, as well as downpipe 3, which leads back to the rest of the exhaust.

Downpipe 3 is a single pipe that turns into a dual so it can be mated to the stock exhaust leading over the rear axle. Turbonetics provides new clamps for mating the pipes. One thing we ran into-and you will, too-is that when you first look at where all the pipes are supposed to be mounted, you'll think the folks at Turbonetics have lost their minds. But they fit. It's tight and you may have to move the pipes around and persuade them into place, but they will install as shown.

Getting back to the turbocharger itself, this is where the oil drain hose installs. From this fitting, the oil circulates back to the oil pan.

This 11/48-inch NPT x 51/432-inch 90-degree boost fitting installs in the turbocharger compressor housing.

Remember the water lines? Turbonetics recommends they be installed onto the turbocharger before putting it in place. They're 52 inches long and will need to be heat wrapped.

After all that, we're able to mount the assembly into place. At this point, we need to mount the turbocharger and connect the water and oil lines. Use a V-band clamp to attach downpipe 1 to the turbocharger exhaust housing.

Now we find boost tube 1 to install the Raptor blow-off valve, which is used as a second safety measure to keep from sending too much boost through the engine. When the throttle closes under driving conditions, the valve allows the extra boost pressure to blow-off. Without one, the turbocharger or the throttle blade could get damaged because the boost will find a place to escape.

Here's where boost tube 1 and the blow-off valve are installed. The tube is installed between the intercooler and the turbo. A coupler connects boost tube 1 to boost tube 2, which is connected to the intercooler.

Both tubes leading from the intercooler use framerail passages to enter the engine compartment. This is another area where it seems as though these components won't work, but trust us-they fit. The Zamboni team did this part of the installation Orange County Choppers-style. They mocked up everything minus hose clamps to make sure we had everything in the right place. Then we went back and installed hose clamps to finish this part of the job.

Here's where boost tube 3 installs. This tube takes air that has been cooled by the intercooler and feeds it to the engine via boost tube 4.

This is boost tube 4, which leads from boost tube 3 to the throttle body. You can see that Turbonetics provides a new upper radiator hose. We've also mounted the heat shield onto the turbocharger's exhaust housing to keep underhood heat to a minimum.

Here's the finished product. The air intake tube is mounted to the turbocharger and includes a mass air meter provision. The factory mass air meter is modified, and a new air temperature sensor is installed in boost tube 4, which is the one connected to the throttle body. As you can see, the overflow reservoir is relocated to the shock tower. Turbonetics includes 5 quarts of its specially formulated synthetic oil and recommends changing it every 3,000 miles.

  Baseline* Turbonetics** Difference
3,500 189 283 245 368 56 85
3,750 207 290 280 392 73 102
4,000 228 299 293 395 65 96
4,250 249 307 326 403 77 96
4,500 264 308 353 412 89 104
4,750 276 305 371 411 95 106
5,000 289 303 387 406 98 103
5,250 296 296 403 403 107 107
5,500 297 283 402 383 105 {{{100}}}
5,750 N/A N/A 402 367 N/A N/A
6,000 N/A N/A 396 346 N/A N/A
6,250 N/A N/A 397 334 N/A N/A

'05 Roush, Stainless Works long-tube headers, cold-air kit, custom tune'05 Roush, Turbonetics single-turbo kit, SCT tune

Why is car owner Darrell Pitts smiling? (Yes, that is a smile.) His self-named Quiet Sleeper Roush convertible makes more than 400 hp to the wheels and it has room to grow. Before adding the turbo, Darrell's Roush boasted Stainless Works long-tube headers, a cold-air kit, and a custom tune. That's why the earlier numbers are relatively high.

With the Turbonetics kit, those headers were removed and the stock manifolds were reinstalled. With the included SCT flash tool and a Zamboni Speed and Custom tune, Darrell's single-turbo Roush made 407 hp and 414 lb-ft of torque on Zamboni's in-house Dynojet. You don't see those numbers on the included chart because they occurred between focused rpm numbers.

For those thinking these numbers aren't respectable, the Roush made these numbers at only 7 pounds of boost and a rich air/fuel mixture averaging an 11.59 ratio across the board. More boost is available, and the tune leaves more power on the table. Zamboni wants to make sure Darrell enjoys the car and gets used to the new power. In the future, the tune will be maximized for more.

Even so, we drove the car, and it's plenty fun the way it is. Sorry about the tires, Darrell.