Introduction: Why the Greddy Muffler Makes Sense for Your Integra Type S

The Acura Integra Type S is already a formidable machine—a turbocharged, manual-transmission hatchback that blends daily usability with track-ready aggression. Yet for many enthusiasts, the factory exhaust system leaves one thing on the table: character. The stock muffler is tuned for noise compliance, producing a polite note that doesn’t match the car’s sporting intent. Enter the Greddy muffler. Known for decades in the JDM tuning world, Greddy (a brand under the Trust umbrella) offers a range of exhaust components that deliver a deeper, more aggressive tone while often reducing weight and improving exhaust flow. This guide provides a comprehensive, step-by-step installation process for bolting a Greddy muffler onto your Integra Type S, along with an in-depth sound comparison to help you decide if the upgrade aligns with your expectations.

Whether you’re a first-time installer or a seasoned gearhead, the process is straightforward—but careful attention to detail ensures a leak-free fit and optimal performance. We’ll cover everything from tool selection to final sound testing, so you can install with confidence.

Tools and Materials: What You’ll Need for a Clean Installation

A successful muffler swap relies on having the right gear. While the basic list is short, a few specialty items will make the job faster and safer.

  • Greddy Muffler (and compatible piping kit if required) – Confirm it’s the correct part for the Integra Type S (DE5 chassis). Some Greddy mufflers come with an adapter pipe; others are direct bolt-on to the stock mid-pipe.
  • Socket wrench set – Metric sockets from 10mm to 14mm, plus a 17mm or 19mm for the main exhaust flange bolts. A ratchet with a long extension helps reach tight spots.
  • Jack and two (or four) jack stands – A low-profile floor jack is ideal. Never rely on the factory scissor jack for under-car work.
  • Pipe cutter or reciprocating saw – Only if the Greddy muffler requires a custom cut to the existing exhaust pipe. Otherwise, skip this.
  • Exhaust hanger removal tool – This inexpensive tool pries rubber hangers off without damaging them. A flathead screwdriver and penetrating oil can substitute, but the dedicated tool saves time.
  • Penetrating oil (e.g., WD-40 Specialist or PB Blaster) – Essential for loosening rusted bolts and hangers, especially if the car is driven in salt-prone regions.
  • Safety goggles and gloves – Exhaust system components can have sharp edges and rust flakes. Protect your eyes and hands.
  • Rubber mallet – Useful for gently persuading stubborn hangers or alignment without damaging the new muffler.
  • Optional but recommended: New exhaust gasket (donut or metal crush ring) – The gasket between the muffler flange and the mid-pipe often compresses permanently; replacing it ensures a leak-free seal. Also consider anti-seize compound for bolt threads.

Preparation: Set the Stage for Success

Before you crawl under the car, take a few minutes to prepare both the vehicle and your workspace. Park the Integra Type S on a level, solid surface—preferably a garage floor or paved driveway. Let the engine cool completely; exhaust components can reach temperatures that cause burns even an hour after driving.

Clear the area of obstacles and arrange your tools within easy reach. If you’ll be working on jack stands, chock the front wheels to prevent the car from rolling. For added stability, use a jack stand under each rear subframe jack point (consult your owner’s manual for the correct locations). Some owners prefer to also lift the front slightly to create more room, but lifting only the rear is sufficient for a muffler swap.

While you’re prepping, consider taking a “before” sound recording or note the exhaust note at idle and under light throttle. This baseline will make the sound comparison more concrete later.

Step 1: Safely Lift the Vehicle

Position the jack under the rear center jacking point (the reinforced area behind the rear subframe). Pump the jack until it contacts the underbody, then continue lifting until both rear wheels are about 10-12 inches off the ground. Immediately place jack stands under the designated lift points on each side—these are typically small notches near the rear suspension arms. Lower the jack onto the stands and verify the car is stable before sliding underneath. Give the car a gentle shake at the bumper to confirm it’s secure.

Step 2: Remove the Stock Muffler

Begin by spraying penetrating oil on all bolts, nuts, and rubber hanger mounts you’ll be removing. Allow it to soak for at least five minutes. The stock muffler attaches at three points: the flange where it meets the mid-pipe, and two rubber hangers (one near the muffler body, one near the tip).

Using a socket wrench, loosen and remove the two bolts securing the flange. These are often 14mm or 12mm. If they’re tight, use a ratchet with a breaker bar or a long handle for leverage. The flange may separate with a slight pop; be careful not to let the muffler fall.

Next, use the exhaust hanger removal tool (or a flathead screwdriver) to pry the rubber hangers off the metal studs on the muffler. Work slowly to avoid tearing the rubber. If a hanger is hardened or stuck, apply more penetrating oil and wiggle it. Once all hangers are free, lower the heavy stock muffler to the ground. Depending on the Integra Type S’s build date, the stock muffler may have a heat shield attached—if so, unbolt it separately before removing the muffler.

Pro tip: If the flange bolts are rust-frozen, apply heat with a propane torch (carefully, away from fuel lines) before trying to wrench them. Alternatively, cut them off with a reciprocating saw and replace with new bolts.

Step 3: Modifying the Exhaust Pipe (If Your Greddy Muffler Requires It)

Not all Greddy mufflers are direct bolt-on. Some aftermarket designs use a universal fit with a clamp or weld-on adapter. Check the installation instructions that came with your muffler. If it requires cutting the stock pipe, measure twice and cut once.

Using a pipe cutter is cleaner than a saw, but a reciprocating saw with a metal-cutting blade works well. Mark the cut point with a marker, then cut squarely. Deburr the inside edge of the pipe with a file to prevent turbulence and potential rattling. If the muffler uses a slip-fit connection, you may need to expand the pipe end slightly with a pipe expander tool. For clamp-type connections, ensure the cut pipe extends at least 2 inches past the clamp position to avoid slipping.

If the Greddy muffler is a full cat-back system replacement (rare for just a muffler, but possible), you’ll instead unbolt the entire rear section from the mid-pipe—no cutting needed.

Step 4: Install the Greddy Muffler

Before fitting the new muffler, check that the mounting flanges are clean and free of old gasket material. Apply a new gasket if the stock one is compressed or damaged—a fresh gasket is cheap insurance against leaks.

Slide the Greddy muffler’s inlet pipe into the exhaust pipe (or align the flanges). For slip-fit connections, push the muffler fully onto the pipe until it stops. For flange connections, thread the bolts through loosely—don’t tighten yet. Reattach the rubber hangers to the muffler’s mounting studs; you may need to use the rubber mallet to gently tap the hangers into place if the muffler is positioned slightly differently than stock.

Once the muffler is hanging from the hangers, align the tip with the rear bumper cutout. The Integra Type S has a specific opening; position the tip so it is centered and doesn’t rub the bumper. Tighten the flange bolts to the manufacturer’s specified torque (typically 30-40 ft-lbs). If using a clamp, tighten it evenly around the pipe. Finally, double-check that all hangers are seated fully and that the muffler doesn’t contact any part of the underbody, heat shields, or suspension components when you bounce the car.

Step 5: Leak Check and Final Adjustments

Start the engine. Immediately listen for any hissing or ticking sounds at the connection points. A small exhaust leak can worsen over time and affect sound quality and performance. Have a helper briefly block the tailpipe with a rag or gloved hand—if the engine stumbles slightly that’s normal, but if you hear additional leaks, the blockage is pressurizing the system and revealing them.

With the engine at idle, inspect all joints with your hand (carefully, they get hot fast) or use a piece of tissue paper to feel for puffs of exhaust. If you detect a leak at the flange, tighten the bolts another 5-10 ft-lbs (do not over-torque). For clamp joints, reposition the clamp and re-tighten.

If everything is sealed, let the engine run to operating temperature. This helps the new muffler settle into position. After a few minutes, turn off the engine, let it cool, and re-torque the bolts again—metal expands and contracts, so a second tightening ensures long-term stability.

Lower the car from jack stands and go for a short test drive. Pay attention to any drone at cruising speeds or vibrations under load. If the muffler contacts the underbody, you may need to adjust the hanger position or add a small spacer.

Sound Comparison: Before vs. After the Greddy Muffler

The primary reason most owners swap their muffler is the change in acoustic character. The stock Integra Type S exhaust is surprisingly muted from the factory—likely to meet European drive-by noise regulations. Here’s a detailed breakdown of what you’ll notice.

Stock Muffler Characteristics

  • Idle: Barely audible inside the cabin. A faint, low-frequency hum from the rear. Outside, the sound is present but non-intrusive—a polite burble.
  • Low RPM cruise (2,000–3,000 rpm): Virtually silent unless accelerating moderately. The car feels quiet and refined, similar to a standard Acura sedan.
  • Full throttle (5,500 rpm+): A slightly sportier note emerges, but it’s still filtered—more “background rush” than an aggressive snarl. The turbo whistle dominates over the exhaust.
  • Volume (approximate): Around 78-82 dB at 3,000 rpm under light load (measured from behind the car).

Greddy Muffler Characteristics

  • Idle: A deeper, more resonant tone at idle. The engine “lopes” slightly with a heavier beat. Still civil, but unmistakably aftermarket.
  • Low RPM cruise: Noticeably more presence. You’ll hear a soft rumble even at steady throttle, but it’s not offensive—no drone at 2,500 rpm. The sound is more organic and lets through more of the engine’s mechanical character.
  • Full throttle: Transforms into a full-throated roar. The exhaust note becomes aggressive, with a raw edge on the upper rev ranges. Turbo spool is still audible, but now the exhaust note matches the car’s performance. Expect pops and crackles on deceleration (especially if the car has a stock tune that allows overrun).
  • Volume (approximate): 88-92 dB at 3,000 rpm under light load—an increase of about 10 dB, which is roughly twice as loud to human ears. Greddy’s official exhaust page provides decibel charts for some models, though actual results vary by installation.

Subjective impressions

Many owners report that the Greddy muffler makes the Integra Type S sound like it “should have from the factory.” The tone is deeper and richer, without the raspiness common to cheaper mufflers. The increase in volume is noticeable but not overwhelming—daily driving remains pleasant, and highway cruising produces minimal drone if the muffler resonates properly. Compared to a full cat-back system, the muffler-only swap preserves the stock mid-pipe’s catalyst and resonator, so the sound is still relatively civilized. If you want a more dramatic transformation, pairing the Greddy muffler with a mid-pipe delete (or a Greddy cat-back) will amplify both volume and aggression.

Performance Benefits: Beyond Sound

While sound is the immediate payoff, a Greddy muffler can offer modest performance gains. The factory muffler is heavy and restrictive—designed for noise reduction and cost efficiency. Greddy mufflers typically use a straight-through perforated core or chambered design with larger internal volume, reducing backpressure. On a turbocharged engine like the K20C1 in the Integra Type S, less backpressure allows the turbo to spool slightly more freely, though the difference is marginal (2-5 hp at most). More noticeable is weight savings: a Greddy muffler can be 8-12 pounds lighter than the stock unit, reducing unsprung mass in the rear. Combined with the improved sound, the subjective feeling of a “freer” revving engine is real.

For those considering further modifications, installing a Greddy muffler now sets the stage for a future cat-back or downpipe upgrade, since the muffler will remain compatible with most aftermarket mid-pipes using standard 2.5-inch or 3-inch connections.

Maintenance and Long-Term Care

Greddy mufflers are built to last, but a little care extends their life. Regular undercar washes (especially in winter) prevent salt buildup on the stainless steel or titanium finish. If the muffler develops a patina of light surface rust (on non-stainless variants), a high-temperature exhaust paint can restore appearance. Check the flange bolts and clamp torque every oil change—vibrations can loosen them over time. Finally, listen for rattles: if the internal baffles break free (rare with Greddy), the muffler will buzz; contact the manufacturer under warranty if that occurs.

Conclusion: Is the Greddy Muffler Worth It?

For Integra Type S owners seeking a more engaging exhaust note without the hassle of a full exhaust system replacement, the Greddy muffler is an excellent upgrade. The installation is a straightforward weekend project that requires basic tools and a little patience. The sound transformation—from muted to muscular—adds a new layer of enjoyment whether you’re daily driving or carving back roads. With a reputable brand like Greddy, you also gain peace of mind in build quality. If you’ve been on the fence, this step-by-step guide gives you everything you need to install it yourself and hear the difference firsthand. For further reading on exhaust theory and sound comparisons, check enthusiast forums dedicated to high-performance exhausts, or consult AcuraWorld for owner feedback.