Quality rotor bearings are...
Quality rotor bearings are a must due to a twin-screw's rpm and load characteristics. The twin rings of hard plastic on the bearings outer shell allow for slight looseness of the bearing in its bore (in the plate in the background). This allows the bearings to adjust to many major stresses as the blower heats and cools. And that shape cut into the bearing bulkhead in the background is not decorative. It, along with rotor shape, controls the supercharger's breathing. Engineer Billy Tally says when it came to breathing and porting, he came to see the twin-screw as a two-stroke engine rotating on its side. Since Billy cut his teeth with motorcycle legend Kel Carruthers, he felt right at home. Also noteworthy is the blower's intake aperture in the bearing plate: 3.5 inches, which is 89mm, so a 90mm throttle body or mass air meter ought to be sufficient, or so the thinking goes.
Electronic tuning is handled via a DiabloSport Predator. Techco supplies two software files, one for 91-octane pump fuel, the other for East Coast 93 octane. Techco's engineers use the same electronic tuning black boxes as OEMs such as Ford and GM employ in their engineering departments. These are much more expensive than the usual aftermarket tuning hardware, but they get to the basic code level of the engine management system so they promise better driveability. It's also a holdover from Saleen days, when John Spruill was writing code as an OEM, not as a tuner.
"I hate gaskets," Tally sneered more than once as we poked around the new supercharger. He's fed up with traditional paper gaskets that tear, squish and fail to seal well. So there are no paper gaskets in the Techco blower, only simple O-rings and a few complex rubber-coated gaskets. These gaskets were all selected from existing automotive stocks to keep costs down and supply sources numerous.
Techco went to fastener specialist ARP for all the significant hardware in the blower. This is an expensive way to thread things together, but the torque consistency and overall quality of the high-strength yet ductile ARP hardware make it worthwhile say Techco engineers.
Furthermore, the entire blower is dowel-pinned to maintain the precise alignments made possible by the CNC machining. While there are many places in a screw blower where precision is paramount, from a hot rodder's perspective pinning the intake runners to the case means the Techco blower is port matched for all practical purposes.
The Techco blower installs like other familiar screw or Roots supercharger. For example, Techco supplies its screw blower in a main assembly consisting of the supercharger, intake manifolding, charge cooler, drive, bypass valve, 36 lb/hr fuel injectors and fuel rails. These parts are shipped in one assembly, so fitting it is much like changing an intake manifold. You'll definitely want at least one helper when humping the blower assembly onto the engine.
Connections atop the engine are plug-and-play with no wires to cut or lines to bend. The stock fuel supply plugs into the Techco fuel rails as does the injector wiring harness, sensor wires, and so on. New hoses are supplied as required, as is a jumper harness to accommodate the reversed alternator.
No changes to the fuel pump or lines are required, so there's no need to drop the fuel tank. Likewise, no oil line plumbing is required as the Techco blower uses self-contained lubrication. In fact, there's nothing to do under the engine unless accessing the crankshaft pulley is easier that way for you.
The Techco blower drive attaches via brackets to the front of the engine and requires reversing the alternator so its drive pulley faces the engine. The alternator pulley is changed to a lower-profile piece that retains the same pulley diameter, but gives more clearance.
Mounting the charge cooling system radiator and pump is best done by removing the front bumper cap to allow maximum access. If this seems bothersome, the radiator and pump can be installed without removing the bumper cap, but Techco workers say they find the job easier that way.
Techco technicians have the installation down to a single day, but first-time shops should figure on more than eight hours, and home-based enthusiasts need to block out a weekend for this job. Techco guestimates 10 hours for a home install. If it were us, we'd start on Friday night if we needed to drive the car to work Monday morning.
We're showing a few photos of the installation highlights, but are not showing the entire job. That would take up too much room, and what we witnessed was a blower and bracket change on the Techco engineering mule, not a virgin installation.
 Two beefy billet aluminum...  Two beefy billet aluminum brackets are used at the front of the engine. The one at left is part of the alternator relocation scheme; the bracket at right is part blower-drive support and part mounting pad for the blower belt's manually adjusted tensioner. |  Techco's blower pulley uses...  Techco's blower pulley uses this simple wrench for installation and pulley changes. Two pins on the wrench engage two holes on the pulley for quick and easy pulley R&R. |  Techco makes its own pulleys,...  Techco makes its own pulleys, including this idler and crankshaft pulley. All are eight-rib and black-anodized for durability. |
 Once past the emissions-legal...  Once past the emissions-legal Basic Techco kit, T1 through T3 use the cold air intake (left). The T4 uses the same animal but with the longer air filter (right). Both use a 100mm mass air that repackages the stock mass air electronics and wire probes. The T4 version doesn't use the air dam as the longer filter won't fit inside it, and race cars typically have ample fender or underhood area to mount the larger intake. |  Looking through an open intake...  Looking through an open intake runner with the charge cooler core removed shows the relationship of the bypass valve to its actuator. This valve is normally open during part-throttle cruising to nearly eliminate load. Blower dyno testing shows it takes less than one horsepower to drive the blower under no-boost conditions. |  Techco uses this coolant crossover...  Techco uses this coolant crossover casting to transfer coolant between cylinder banks. As a casting, it's normally well hidden under the supercharger or thermostat housing. |