The VQ37VHR engine powers iconic Nissan and Infiniti vehicles like the 370Z, G37, and Q50. Known for its high-revving nature and linear power delivery, the VQ37 responds exceptionally well to exhaust upgrades. Replacing the restrictive factory system can unlock noticeable horsepower gains, improve throttle response, and transform the engine’s character. This expanded guide compares three top-tier exhaust brands—Borla, Invidia, and Stillen—to help you choose the right system for your build.

Understanding High-Performance Exhausts

High-performance exhaust systems reduce backpressure, improve exhaust scavenging, and shed weight compared to OEM parts. The primary types for VQ37 applications include axle-back systems (simplest, affects sound mostly), cat-back systems (replaces from the catalytic converters back, offers moderate gains), and header-back or turbo-back systems (full replacement for maximum power). Most enthusiasts start with a cat-back exhaust for the best balance of power, sound, and cost.

Key factors to evaluate when choosing an exhaust: material quality (304 stainless steel is standard for longevity), sound profile (aggressive, refined, or quiet), fitment precision (direct bolt-on vs. requiring modifications), weight savings, and warranty support. The three brands covered here are among the most popular and respected in the VQ community.

Borla Exhaust Systems

Borla has built its reputation on American-made exhaust systems with proprietary technology like multi-core muffler designs and Aircraft-Quality T-304L stainless steel. Their VQ37 offerings deliver a deep, muscular tone with minimal interior drone—a key concern for daily drivers.

Material and Construction

All Borla systems use T-304L stainless steel (aerospace grade), mandrel-bent tubing, and CNC precision robotic welding. They offer a Million-Mile Warranty that covers defects and corrosion, reflecting their confidence in durability. The systems are fully polished for a mirror-like finish.

Sound Characteristics

Borla’s two main lineups for the VQ37 are the S-Type and ATAK. The S-Type provides a refined yet aggressive tone that builds into a satisfying roar under wide-open throttle, with virtually no drone at cruising speeds. The ATAK (Acoustically Tuned Applied Kinetics) is louder and more raw, designed for track use or drivers who want maximum attention. Both systems retain the VQ’s characteristic rasp while adding depth.

  • S-Type: Balanced sound, moderate volume, ideal for street-driven cars.
  • ATAK: Aggressive, race-inspired sound, louder inside and out.

Performance Gains

Borla claims gains of 5–12 horsepower and 8–10 lb-ft of torque depending on the model and supporting mods. Real-world dyno results from forums show consistent gains of 8–10 whp on otherwise stock VQ37s. The systems sharpen throttle response and help the engine breathe more freely at higher RPMs.

  • Borla S-Type Cat-Back (140650): For 370Z/G37, features dual-wall polished tips.
  • Borla ATAK Cat-Back (140651): Same chassis but with louder mufflers and larger 4.0-inch tips.

Installation and Fitment

Borla systems are true bolt-on designs with all necessary hardware included. Most installations take 2–3 hours for a home mechanic. Fitment is generally excellent, though some G37 owners report needing to adjust hangers slightly for optimal clearance. They are 50-state legal (except models without catalytic converters).

Invidia Exhaust Systems

Invidia has become a household name in the import tuning world, known for aggressive styling and a raw, JDM-inspired sound. Their VQ37 exhausts are offered in two distinct flavors: the Q300 (daily-friendly) and the N1 (track-oriented).

Material and Construction

Invidia uses high-grade 304 stainless steel with polished surfaces and robotic TIG welding. The mufflers are chambered and baffled for volume control. The N1 series features a straight-through design with a single large muffler, while the Q300 uses a dual-muffler configuration. Both are mandrel-bent for smooth airflow.

Sound Characteristics

The Q300 is known for a deep, refined tone that is mild at idle but opens up under load. It has minimal drone, making it suitable for daily driving. The N1 is louder, raspier, and exhibits a pronounced “burble” on deceleration. It is distinctly aggressive and can be too loud for some neighborhoods.

  • Q300: Smooth bass note, reserved at low RPM, exhilarating at high RPM.
  • N1: Raw, race-bred sound, significant drone at freeway speeds, very loud.

Performance Gains

Invidia dyno results show 6–10 horsepower gains across the powerband, with the N1 offering slightly more top-end due to its less restrictive muffler. Both systems improve exhaust flow and reduce backpressure. The N1 is lighter than stock (saves about 10–15 lbs), while the Q300 is comparable in weight.

  • Invidia Q300 Cat-Back (HS06ZE0BX): For 370Z, polished tips, dual 3.0-inch piping.
  • Invidia N1 Cat-Back (HS06N1SBX): Single 3.0-inch piping to a 4.5-inch cannon-style tip.

Installation and Fitment

Invidia systems are direct bolt-on with all hardware. The Q300 fits tight around the rear subframe; occasional trimming of rubber hangers may be needed. The N1 is simpler but can hang low on some applications—check clearance. They are not legal for on-road use in some states without high-flow catalytic converters (check local laws).

Stillen Exhaust Systems

Stillen has a long motorsports history, with deep roots in Nissan performance. Their VQ37 exhausts are engineered for maximum power extraction while maintaining a refined, non-droning sound. Stillen offers both axle-back and cat-back configurations.

Material and Construction

Stillen uses aerospace-grade 304 stainless steel with a multi-step polishing process. The mufflers have unique internal chambers designed to cancel drone frequencies while maintaining flow. The welds are consistently smooth and durable. Stillen products come with a Lifetime Warranty for the original purchaser.

Sound Characteristics

Stillen targets a refined aggressive sound—loud when you get on it, quiet when cruising. The cat-back system produces a deep, European-esque tone with minimal rasp. The axle-back is slightly milder but still adds a sporty note. Stillen systems are among the quietest of the three brands at highway speeds, making them ideal for daily drivers who want power without the roar.

Performance Gains

Stillen claims 8–15 horsepower gains for their cat-back, and independent dynos show consistent 10–12 whp increases on 93-octane fuel. The system also yields 8–10 lb-ft of torque in the mid-range. Stillen’s R&D on the VQ37 is extensive, and their exhausts are often paired with their cold air intakes for compounded gains.

  • Stillen Cat-Back Exhaust (ST-38001): Dual 2.5-inch pipes into a dual 3.0-inch exit, large polished tips.
  • Stillen Axle-Back Exhaust (ST-38002): Replaces only the rear muffler section, retains factory mid-pipe.

Installation and Fitment

Both Stillen systems bolt directly to OEM hangers. The cat-back includes a mid-pipe that fits neatly over the rear axle. The axle-back is even simpler—about an hour job. Fitment is precise, with no sagging or tip misalignment reported. They are 50-state legal when used with stock catalytic converters.

Head-to-Head Comparison

Choosing between Borla, Invidia, and Stillen depends on priorities. Here’s a detailed breakdown:

Sound Profile

  • Loudest: Invidia N1
  • Aggressive but refined: Borla ATAK, Stillen Cat-Back
  • Mildest: Invidia Q300, Borla S-Type, Stillen Axle-Back

Performance Potential

  • Highest dyno gains: Stillen Cat-Back and Borla ATAK (10–15 hp)
  • Mid-range torque: Borla S-Type and Stillen
  • Top-end power: Invidia N1

Drone Control

  • Best: Stillen (engineered with Helmholtz resonators), Borla S-Type
  • Good: Invidia Q300
  • Poor: Invidia N1 (significant drone at 2,500–3,000 rpm)

Weight Savings

  • Lightest: Invidia N1 (approx. 35 lbs total, saves 10 lbs vs. OEM)
  • Moderate: Borla S-Type (approx. 40 lbs)
  • Heaviest: Stillen Cat-Back (approx. 45 lbs, but still lighter than stock)

Price Range (Approximate as of 2025)

  • Borla S-Type: $1,100–$1,300
  • Borla ATAK: $1,200–$1,400
  • Invidia Q300: $800–$950
  • Invidia N1: $750–$900
  • Stillen Cat-Back: $1,150–$1,350
  • Stillen Axle-Back: $550–$700

Warranty

  • Borla: Million-Mile
  • Invidia: Lifetime (limited) for original owner
  • Stillen: Lifetime for original purchaser

Ease of Installation

All three are straightforward DIY projects. Borla and Stillen provide the most complete hardware and instructions. Invidia may require slight trimming of rubber hangers for perfect alignment.

Additional Considerations for VQ37 Exhaust Upgrades

Headers and Test Pipes

Pairing a cat-back with long-tube headers and test pipes (or high-flow cats) dramatically increases volume and power. Borla, Invidia, and Stillen cat-backs all mate well with aftermarket headers. However, the N1 may become unbearably loud with a full header-back setup—it’s best reserved for track use.

Resonated vs. Non-Resonated Mid-Pipes

Some modifications add a resonated mid-pipe to reduce rasp and drone. Both Borla and Stillen incorporate resonator technology in their systems. The Invidia N1 can be paired with an optional resonated test pipe to tame the sound.

Emissions and Legalities

Removing catalytic converters or using test pipes is illegal for street use in most states. All three brand’s cat-back systems are emissions-compliant when used with factory cats. Check local laws before installing non-compliant components.

ECU Tuning

While not required for a cat-back, an ECU tune (e.g., from Uprev or Ecutek) can optimize air-fuel ratios and advance timing to extract full benefit. Many users report an additional 5–10 hp from a tune paired with one of these exhausts.

Maintenance

Stainless steel exhausts require minimal upkeep. Rinsing off road salt and occasional polishing of tips will keep them looking new. Borla’s polished stainless tips are the easiest to maintain; Invidia’s N1 tip can tarnish if not cleaned regularly.

Community Feedback and Real-World Experience

Online forums like The370Z.com and MyG37.com contain thousands of owner reviews. Common themes: Borla is praised for build quality and warranty but can be pricey. Invidia offers the best value for the sound enthusiast, especially the Q300. Stillen is the go-to for those wanting minimal drone with genuine power gains. However, the N1’s drone is a frequent complaint for daily drivers. Some owners note that Stillen’s cat-back can be difficult to align perfectly on early 370Z models.

Conclusion

The VQ37 demands an exhaust that matches its lively character. Borla delivers a premium, drone-free experience with two distinct sound levels. Invidia provides budget-friendly aggressive options for those who prioritize volume. Stillen focuses on engineering refinement and proven power gains. Evaluate your driving style—daily commuting, weekend canyon carving, or track days—and choose accordingly. Any of these systems will unlock the VQ37’s potential, transforming your car’s personality.

For further research, visit the official sites: Borla Exhaust, Invidia USA, and Stillen. Dyno charts and sound clips are available on Z1 Motorsports.