 The STS Turbo system for the...  The STS Turbo system for the '98-'02 LS1-powered Firebirds retails for $3,995 and comes complete with everything needed to bolt on well over 100 rear-wheel horsepower |
 Oil is fed to the STS turbo...  Oil is fed to the STS turbo via a -4 AN line that will get its oil supply from the aluminum oil pressure block-off plate located directly above the oil filter on the engine block. The block-off plate is retained with two 10mm bolts. |
 After loosening the bolts,...  After loosening the bolts, use a small prybar or large screwdriver and push the catalytic converter outward, allowing enough access to remove the bolts and the plate |
 The aluminum block-off plate...  The aluminum block-off plate is partially drilled from the factory, so to complete the job, mount it in a bench vice and proceed to drill out the oil pressure port with a 211/464-inch drill bit. |
In Part I of this story (Jan. '06), we introduced the Squires Turbo Systems (STS) rear-mounted turbocharger package for the '98-'02 LS1-powered Firebirds. The base STS kit retails for $3,995 and comes complete with everything needed to bolt on well over 100 rear-wheel horsepower in about a day's time.
What makes this system unique is that, instead of a traditional underhood turbocharger placement, STS utilized the factory exhaust manifolds, catalytic converters, and exhaust, and placed the turbo assembly where the muffler used to sit. The boost from the turbocharger travels through HPC-coated piping, along the driver-side framerails and into the engine compartment, where it flows fast and furious into the GM throttle body. The innovative approach that STS took in designing this "Subterranean" turbo system for your late-model F-body garnered the company the coveted GM Design Award for Best Performance Product at the '04 SEMA Show.
According to Billy May, owner of Texas Rear Turbos, an STS factory trained distributor and full-service installer, "The STS turbocharger kit for late-model Firebirds and GTOs is an excellent choice for the street that has been proven to be easy to install and very reliable, especially for daily driver applications.
"In order to put down 400 or more rear-wheel-horsepower on a naturally aspirated LT1- or LS1/2-based application, a cam that sacrifices idle quality and maximizes the midrange and top-end power is usually chosen. Not only will the STS turbo system produce the horsepower that the enthusiast is looking for while retaining the stock cam, but the powerband of the turbocharged car isn't nearly as peaky. By the time you rack up all the costs of heads, cam, exhaust, and other related parts to put your naturally aspirated car into the 400-rwhp range, you could have had a turbo system. If you decide later on that you want to sell your car or go back to stock, the system can be removed in a few hours and you are but a mouse click away from selling it on eBay.
"Our business was formed with customer service as the main priority. Although we are located in Texas, customers from as far away as California and Georgia have traveled to our shop because we go out of our way to understand their goals for their car, and then we take it from there. Whether it's a street application or a nasty dragstrip warrior, our relationship with STS allows us to custom tailor a system to match the customer's needs. As an enthusiast who owns an LS1 Formula, there's no better stress relief than banging a few gears and still knocking down 20-plus miles to the gallon."
Follow along as we continue installing the STS rear-turbo system on an LS1-equipped '00 Formula WS6. In the first installment, we bench assembled the turbocharger and then removed the Formula's stock factory muffler and tailpipes to prepare to mount the turbo. We then moved under the hood and removed the factory airbox, lid, and MAF. Next we attached the MAF to the STS tubing to effectively move it out of the factory location and line it up with the STS piping that will come from the turbocharger.
Although the STS base package is set up to boost your Bird to the tune of 5psi, we opted to turn up the wick and raise the boost to 7 1/2 psi, with the use of STS' sequential methanol injection kit. Installation of the system will continue at Real Performance Motorsports and DuSold Designs, both located in Lewisville, Texas, by technicians from Texas Rear Turbos.