Why Upgrade to a Borla S‑Type 3‑Inch Turbo‑Back Exhaust?

The exhaust system is a critical component of any forced‑induction engine. Replacing the restrictive factory system with a Borla S‑Type 3‑inch turbo‑back exhaust delivers measurable improvements in airflow, horsepower, and throttle response. The S‑Type sound profile offers a deep, aggressive tone without the drone often associated with larger‑diameter exhausts. This guide provides a comprehensive, step‑by‑step installation walkthrough to help you achieve a perfect fit and maximize the performance potential of your vehicle.

Understanding Turbo‑Back Exhaust Systems

A turbo‑back exhaust replaces every component from the turbocharger’s outlet to the tailpipe, including the downpipe, mid‑pipe, and rear section. Unlike a cat‑back system, a turbo‑back setup removes the restrictive factory downpipe and catalytic converter, allowing exhaust gases to exit the turbo with minimal backpressure. The larger 3‑inch diameter reduces flow velocity issues common on high‑output builds, while Borla’s patented multi‑core technology controls sound waves for a refined yet aggressive note. Before starting the installation, it is important to understand that a turbo‑back system may require a custom tune to fully optimize air‑fuel ratios, especially if the downpipe eliminates the primary catalytic converter.

Tools and Materials Needed

Having the correct tools on hand will make the job safer and more efficient. The following list covers everything you will likely need:

  • Socket set – metric and SAE sizes, including deep sockets for stubborn nuts
  • Wrench set – combination wrenches and ratcheting wrenches
  • Jack and jack stands – a quality floor jack and at least four jack stands rated for your vehicle’s weight
  • Safety glasses – to protect against debris and rust flakes
  • Mechanic’s gloves – cut‑resistant and oil‑resistant preferred
  • Torque wrench – a ½‑inch drive torque wrench capable of measuring up to 150 ft‑lb
  • Penetrating oil – aerosol or liquid formula such as WD‑40 Specialist or PB Blaster
  • Exhaust hangers – factory‑style or universal polyurethane hangers (may be needed if originals are worn)
  • Borla S‑Type 3‑inch turbo‑back exhaust system – including all clamps, gaskets, and hardware
  • Optional but recommended: O2 sensor socket, angle grinder with cutting wheel (for seized bolts), and a torch if bolts are rusted

Pre‑Installation Vehicle Preparation

Choosing a Safe Workspace

Select a flat, level surface such as a garage floor or paved driveway. Ensure the area is well‑ventilated, as exhaust fumes and penetrating oil vapors can be hazardous. If working outdoors, avoid wet or windy conditions.

Lifting the Vehicle

Using a floor jack, raise the vehicle and place jack stands under the designated lift points. For most cars, this means the reinforced sills or frame rails near the pinch welds. Never rely solely on the jack. Shake the vehicle gently before crawling underneath to confirm stability.

Cool Down and Safety Gear

Allow the engine and exhaust system to cool completely – ideally several hours after a drive. Hot metal can cause severe burns. Put on your safety glasses and gloves, and keep a fire extinguisher nearby as a precaution.

Step‑by‑Step Removal of the Factory Exhaust System

Apply Penetrating Oil

Spray penetrating oil on every exhaust hanger rubber, flange bolt, and O2 sensor you plan to remove. Allow the oil to soak for at least 10‑15 minutes. For severely rusted hardware, apply a second coat and wait longer.

Disconnect the O2 Sensors

Using an O2 sensor socket or a wrench, carefully unplug each oxygen sensor from the factory exhaust. Gently twist and pull the connectors apart – do not yank the wires. Label each sensor’s location (e.g., “front” and “rear” or “Bank 1 Sensor 1”) to avoid confusion during reinstallation. Thread the sensors out of the downpipe or bungs.

Unbolt the Downpipe from the Turbo

The downpipe connects directly to the turbocharger outlet. Depending on your vehicle, you may need to access bolts from underneath or through the engine bay. Use a socket and ratchet with a universal joint if needed. Support the downpipe as you remove the last bolts to prevent it from dropping suddenly.

Remove the Mid‑Pipe and Rear Section

Starting from the downpipe back, unbolt or unclamp each section. Factory systems often have slip‑fit connections that can be stubborn. Use a rubber mallet to tap joints loose, or carefully pry with a flat‑head screwdriver. Support each section as you work – you may need a helper for the heaviest pieces.

Extract the Exhaust Hangers

Pull the rubber hanger isolators off the metal studs. If they are hardened or cracked, cut them off with a utility knife. Remove the factory hanger brackets if they are being replaced by Borla components. Many Borla systems include new hangers, but you may reuse factory brackets if they are in good shape.

Inspect the Turbo and Flanges

Once the factory exhaust is removed, take a moment to inspect the turbo outlet flange for cracks or warping. Clean the gasket mating surfaces with a wire brush or scotch‑brite pad. If the factory downpipe used a donut gasket, remove all remnants from the turbo flange.

Step‑by‑Step Installation of the Borla S‑Type Exhaust

Prepare the Borla System

Lay out all the Borla components on a clean surface. Verify that all clamps, bolts, and gaskets are present. Borla uses high‑quality T‑304 stainless steel – handle the pipes carefully to avoid scratching the finish. Place the supplied gaskets on the flanges of each section.

Install the Downpipe

Position the new downpipe against the turbo outlet flange. Insert the provided bolts and torque them to the specification given in the Borla instructions (typically 35‑50 ft‑lb for M10 bolts). Do not overtighten or you may strip the threads. Reconnect the O2 sensors to their respective bungs. Some systems may require clocking the sensor wires to avoid rubbing on the driveshaft or subframe.

Attach the Mid‑Pipe

Slide the mid‑pipe onto the downpipe’s outlet. Use the supplied band clamp or v‑band clamp to secure the connection. Do not fully tighten yet – leave the clamp loose enough to allow rotational adjustment. Support the mid‑pipe with a jack or a second person while you position the hangers.

Install the Rear Section and Muffler

Connect the rear section to the mid‑pipe. Again, leave clamps loose. Hang the rear section on the vehicle’s factory hanger studs, using the Borla hanger isolators. The S‑Type muffler is designed to sit in the factory location – adjust the rear section so that the exhaust tips are centered in the bumper cutouts.

Align and Tighten All Connections

With all sections loosely assembled, walk around the vehicle and visually check clearances. Ensure the exhaust does not contact the underbody, driveshaft, or suspension components. A clearance of at least ½‑inch is recommended. Starting from the downpipe and working back, tighten each clamp and bolt to the specified torque. Use a torque wrench to ensure proper clamping force – over‑tightening can distort flanges or crush gaskets.

Install New Hangers as Needed

If the factory hangers were worn, replace them with the Borla‑supplied units. Borla’s hangers are often stiffer to reduce movement while still absorbing vibration. Push the hanger isolators fully onto the metal studs – you may need to lubricate them with soapy water for easier installation.

Post‑Installation Inspection and Testing

Visual Inspection

Look over every joint, hanger, and bolt. Confirm that all clamps are seated correctly and that no wires or brake lines are touching the exhaust. Spin the wheels by hand (if you lifted the axle) to ensure the exhaust does not interfere with the half‑shafts.

Torque Check

Re‑torque all fasteners after the initial startup and cooling cycle. The thermal expansion and contraction can cause bolts to loosen slightly after the first heat cycle. This is a critical step for long‑term reliability.

Leak Test

Start the engine and let it idle. While wearing hearing protection, listen for hissing or ticking sounds at each joint. A small exhaust leak can cause a loss of power and an annoying sound. If you suspect a leak, use a smoke machine or a soapy water spray at the flanges – bubbles indicate a leak.

Check for CEL (Check Engine Light)

If your turbo‑back system eliminates the primary catalytic converter, you may trigger a check engine light for catalyst efficiency. A quality tune or O2 sensor spacer can resolve this. Drive the vehicle for a few miles and scan for codes with an OBD‑II reader. Clear codes if necessary, and ensure the engine management system adapts to the new flow.

Performance Gains and Sound Characteristics

The Borla S‑Type 3‑inch turbo‑back exhaust reduces backpressure by up to 40% compared to a stock 2.5‑inch system. This allows the turbo to spool faster and maintain boost pressure longer, resulting in improved throttle response and a measurable horsepower increase – typically 15‑25 hp on a moderate tune, with even larger gains on high‑boost applications. The S‑Type sound is aggressive under full throttle but remains refined at cruising speeds, thanks to Borla’s “multi‑core” absorber technology. Expect a deep, exotic tone without the raspiness of straight‑pipe setups.

Maintenance Tips for Longevity

Stainless steel exhausts are corrosion‑resistant, but they still require periodic care. Wash off road salt and grime during the winter months. Check the hanger rubbers every oil change for signs of deterioration. Re‑torque the downpipe bolts after the first 500 miles, as the gasket may compress. If you notice any rattles, inspect the heat shields that may have been disturbed during installation.

Troubleshooting Common Issues

Exhaust Drone at Cruising Speeds

The Borla S‑Type is designed to minimize drone, but an incorrect installation can cause resonance. Ensure the exhaust tips are not contacting the bumper and that all hangers are properly seated. If drone persists, consider adding a Borla resonator or a J‑pipe to cancel specific frequencies.

Clamps Slipping

Over‑tightening can deform band clamps, while under‑tightening allows pipes to slip. Use a torque wrench and follow Borla’s recommendations. If the clamp is damaged, replace it – never reuse a crushed clamp.

O2 Sensor Wiring Issues

If the check engine light appears for O2 sensor circuit faults, inspect the wiring for burns or pinches. Route the sensor wires away from hot exhaust surfaces using zip ties or heat‑resistant loom.

Conclusion

Installing a Borla S‑Type 3‑inch turbo‑back exhaust is one of the most rewarding modifications you can make to a turbocharged vehicle. The combination of reduced backpressure, premium materials, and an expertly tuned sound profile transforms both performance and driving enjoyment. By following this step‑by‑step guide, you can complete the installation with confidence and get the most out of your upgraded exhaust system. For further technical details, visit the official Borla Performance Industries website or consult your vehicle’s specific forum community, such as Corvette Forum or Subispeed for turbo‑back applications. Always verify local emissions regulations before removing catalytic converters, and consider a professional tune to fully unlock the system’s potential.