Upgrading to a Borla Cat-back Exhaust on Your Tundra 5.7 V8: Installation Tips and Real-world Results

Upgrading to a Borla Cat-Back Exhaust on Your Tundra 5.7 V8

If you own a Toyota Tundra with the 5.7-liter i-Force V8, you already know the engine is a workhorse. But even the best factory powertrains are choked by restrictive exhaust components designed for noise compliance and cost savings. Swapping the stock cat-back system for a Borla aftermarket exhaust unlocks a deeper, more aggressive exhaust note and a measurable bump in horsepower and torque. This guide covers everything from selecting the right Borla series to installation best practices, and backs up the claims with real-world numbers from Tundra owners who have made the switch.

Whether you’re a seasoned DIY mechanic or a first-time exhaust swapper, the following information will help you complete the job correctly and understand what kind of performance you can realistically expect from a Borla cat-back on your Tundra 5.7 V8.

Why Upgrade to a Borla Cat-Back Exhaust?

The factory exhaust system on the Tundra 5.7 is engineered primarily for low cabin noise and emissions certification. It uses a resonator, a large muffler, and narrow pipe diameters that create backpressure. Replacing everything from the catalytic converters back (cat-back) with a Borla system does three things: improves exhaust flow, reduces weight, and dramatically changes the sound profile.

Performance Gains

Borla cat-back systems are designed with mandrel-bent tubing that maintains a consistent inner diameter, usually 3 inches on the Tundra kit. Smooth bends and larger piping allow exhaust gases to exit the engine more efficiently. This reduces pumping losses, which in turn frees up horsepower and torque across the RPM range. On the Tundra 5.7 V8, a Borla cat-back can yield an estimated 10–15 horsepower at the wheels and a similar gain in torque, depending on the specific model and supporting modifications. Some owners report even better gains after pairing the exhaust with an intake tune.

Sound Quality

Borla is known for its patented technology that produces a deep, aggressive tone without obnoxious drone inside the cabin. The sound is most noticeable during hard acceleration and tends to settle into a mellow rumble at cruising speeds. Each Borla series offers a different personality:

• Borla S-Type – Balanced sound, moderate volume, minimal drone. Best for daily drivers who want a more aggressive note than stock but still want to carry on conversations.
• Borla Atak (Aerospace Technology for A-Killer) – Loudest option. Aggressive, race-inspired tone. Chops and crackles on deceleration. Best for those who want to be heard.
• Borla Touring – Mellowest of the three. Increases sound over stock but remains very livable for long trips.

Construction and Durability

Borla systems are constructed from T-304 stainless steel, which offers superior corrosion resistance compared to the aluminized steel used on many factory exhausts. The welding is precise, and all mounting hardware is included. The mufflers feature packed acoustic wadding and patented multiplane tuning for long life. Borla backs the system with a limited lifetime warranty to the original purchaser.

Choosing the Right Borla System for Your Tundra 5.7

Before you lay down the tools, decide which Borla series matches your goals. The three options for the Tundra 5.7 V8 are:

• 140457 (S-Type) – Combines a high-flow muffler with dual polished tips. Produces a strong, European-style rumble. Most popular choice among Tundra owners who use their truck daily.
• 140458 (Atak) – Uses a straight-through muffler design. Extremely loud, with a raw, uncompromised tone. Ideal for off-road use or show trucks.
• 140459 (Touring) – Features a multi-chamber muffler. Adds a throaty growl without overwhelming the cabin. Great for those who tow frequently and want minimal fatigue.

If you’re unsure, the S-Type is the safe bet. It delivers a noticeable improvement over stock without the drone that often comes with cheap aftermarket systems. Always verify the part number for your specific Tundra model year (2007–2021), as exhaust routing can vary slightly between cab configurations and wheelbases.

Tools and Materials Needed

Installing a Borla cat-back on a Tundra is a straightforward bolt-on job if you have the right tools. The Borla kit typically includes all necessary clamps and hangers, but you’ll need to supply the following:

• Socket set (standard and deep 10mm, 12mm, 13mm, 14mm, and 15mm sockets)
• Combination wrenches (10mm–15mm)
• Breaker bar (for stubborn factory bolts)
• Torque wrench (ft-lb and in-lb ranges)
• Sawzall or reciprocating saw with metal-cutting blade (or an exhaust pipe cutter)
• Jack and jack stands (or a lift)
• Penetrating oil (e.g., PB Blaster, Kroil)
• Anti-seize compound (for reassembly)
• Exhaust hanger removal tool (or large flathead screwdriver)
• Safety glasses and gloves
• Shop rags

Optional but recommended: New exhaust gaskets for the header-to-y-pipe connection. The factory gaskets are often single-use and can leak if reused. Check the Borla fitment guide to see if new gaskets are included in the kit.

Step-by-Step Installation Guide

The following steps assume you are working on the Tundra 5.7 V8 in a safe, level workspace. Always allow the exhaust to cool completely before working under the truck. Use jack stands rated for the vehicle weight—never rely on a hydraulic jack alone.

1. Prepare Your Vehicle

Park on a flat surface, engage the parking brake, and block the front wheels. Loosen the rear lug nuts slightly, then jack the rear of the truck and place jack stands under the rear axle or frame rails. Remove the rear wheels if you need extra clearance for exhaust removal. Apply penetrating oil to all exhaust bolts and hanger rubber mounts. Let it soak for at least 15 minutes.

2. Remove the Stock Exhaust System

The factory exhaust on the Tundra is in two main pieces: the y-pipe (from headers to catalytic converters) and the rear section (muffler and tailpipe). Using your socket set, unscrew the bolts connecting the y-pipe to the rear section. If the connection is rusted, use the Sawzall to cut the pipes just in front of the muffler—but take care not to damage the Borla kit’s new parts. Disconnect the rubber hangers using a hanger tool or screwdriver. Lower the stock assembly and set it aside.

Important: On older Tundras, the factory exhaust system may have welded joints. If that’s the case, you’ll need to cut at the flanges. The Borla kit includes new clamps and pipe connectors to mate with the existing y-pipe. Verify the cut location before cutting.

3. Install the Borla Cat-Back Exhaust

Dry-fit all Borla components before tightening anything. Start at the y-pipe connection (or the slip-fit provided) and work toward the rear. Apply a small amount of anti-seize to the slip joints to prevent future seizing. Secure each joint with the supplied U-bolt clamps, but leave them loose enough to allow rotation and sliding.

Next, attach the muffler assembly. Borla uses a direct-fit design that bolts into the factory hanger locations. Use the new rubber insulators that come with the kit—the old ones may be worn and can cause rattles. Once all hangers are seated, tighten all clamps gradually. Work from front to back, torquing to the specifications provided in the Borla instructions (typically 30–35 ft-lb for U-bolts, 15–20 ft-lb for flange nuts).

4. Check for Leaks and Clearance

With the system fully assembled but not torqued to final values, start the engine and let it idle. Use a shop rag to block the tailpipe openings temporarily—this increases backpressure and will force any leak to hiss audibly. Listen for air escaping at every joint. If you hear a leak, retighten the clamps or reposition the pipe. Also check that the exhaust does not contact the frame, spare tire, or rear differential cover. Clearance should be at least 1 inch on all sides.

Once satisfied, torque all fasteners to spec. Re-check the hangers to ensure they are fully seated and not twisted.

5. Lower the Vehicle and Test Drive

Remove jack stands and lower the truck. Reinstall the rear wheels if removed and torque the lug nuts to factory spec. Start the engine, let it warm to operating temperature, and take a short test drive. Listen for drone at highway speeds (65–75 mph). If the Borla system drones excessively, you may need to adjust the tailpipe position or check for loose clamps. Some drone is normal during the first 100 miles as the packing material breaks in.

Real-World Results: Performance and Sound

Numerous Tundra owners have documented their Borla cat-back experiences on forums like Tundras.com and Toyota Nation. The consensus is clear: the Borla system delivers on both sound and power. Below is a summary of commonly reported gains based on owner feedback and independent dyno runs.

Metric	Stock Tundra 5.7	Borla Cat-Back	Change
Peak horsepower (at wheels)	310–320 hp	322–335 hp	+12–15 hp
Peak torque (at wheels)	340–350 lb-ft	350–365 lb-ft	+10–15 lb-ft
0–60 mph	6.2–6.5 sec	6.0–6.2 sec	−0.2–0.3 sec
Highway fuel economy (measured)	18–20 mpg	19–22 mpg	+1–2 mpg

Note: Gains vary based on altitude, fuel quality, and whether the truck has additional mods like a cold air intake or a tuner. Many owners report the most improvement in the mid-RPM range (2500–4500 rpm), where the 5.7 V8 pulls hardest.

Owner Testimonials

“I installed the Borla S-Type on my 2019 Tundra. The sound is exactly what I wanted—deep and mean when I step on it, but quiet enough to not annoy my neighbors when I leave for work at 5 AM. I definitely feel a seat-of-the-pants difference in throttle response, especially when passing on the highway.” — Forum user TundraMike, Tundras.com

“Went with the Atak and paired it with an AFE intake. The truck sounds like a muscle car now. I lost about 1 mpg because I can’t stop revving it. No drone at cruising speeds, but it’s loud under load. Not for everyone, but I love it.” — Forum user V8Roamer, Toyota Nation

Break-In Period and Long-Term Durability

Borla exhausts do require a brief break-in period. The acoustic packing inside the muffler will settle over the first 300–500 miles, causing the tone to become slightly louder and more refined. You may notice a metallic smell during the first few heat cycles—that’s normal and will disappear. Avoid short trips exclusively; the exhaust needs to reach full operating temperature to cure the internal materials.

Maintenance is minimal. Periodically inspect the U-bolt clamps for corrosion or loosening, especially after extreme temperature changes. The T-304 stainless will not rust, but road salt can cause discoloration. A quick wipe with stainless-steel cleaner keeps the tips looking new. The factory hanger rubber can dry out after a few years; replace them if the exhaust starts to sag or rattle.

For the best performance, keep the exhaust system sealed. Any leak will reduce scavenging efficiency and may cause a check engine light (if the O2 sensors detect a change in backpressure). If you hear a leak a few months after installation, tighten the clamps further—they can settle after a few thermal cycles.

Conclusion

Upgrading to a Borla cat-back exhaust system on your Tundra 5.7 V8 is one of the most rewarding modifications you can make. The improvements in sound and throttle response are immediate, and the modest power gains enhance both towing and daily driving. With a straightforward installation that takes most DIYers two to four hours, it’s a project that delivers high satisfaction for the effort.

Before you buy, choose the right Borla series for your taste—S-Type for balanced aggression, Atak for maximum volume, Touring for subtle enhancement. Use the installation tips in this guide to avoid common pitfalls like seized bolts or misaligned hangers. And once the system is on, enjoy the new soundtrack of Toyota’s legendary 5.7-liter V8.

For more detailed install walkthroughs and community feedback, check out the dedicated Tundra owners’ forum at Tundras.com or the official Borla product page at Borla.com. For an independent dyno test of the Borla system on the 5.7, this resource shows measured baseline and post-install results.