Infiniti G35 Cat-Back Exhaust: HKS vs Borla vs MagnaFlow

A cat-back exhaust is the single most popular upgrade for the 2003–2007 Infiniti G35, and for good reason: it unlocks the naturally aspirated VQ35DE's signature V6 howl while shaving weight and freeing up a few honest horsepower. The V35-chassis G35 — the coupe and sedan that launched Infiniti's performance era — runs a 3.5L V6 making roughly 280 to 298 horsepower and 260 to 274 lb-ft of torque depending on year and transmission. Swap the restrictive factory muffler section for a mandrel-bent stainless cat-back and you get the sound to match the chassis. In this comparison we put three of the best G35 cat-back exhausts head-to-head: the HKS Dual Hi-Power Titanium Tip, the Borla Cat-Back, and the MagnaFlow Street Series.

Why upgrade the G35 cat-back exhaust?

A cat-back exhaust replaces everything from the catalytic converters back — the mid-pipe, mufflers, and tips — with larger-diameter, mandrel-bent tubing that flows better and sounds far better than the factory system. On the VQ35DE, a cat-back alone is a modest power adder: expect a realistic 5 to 12 wheel horsepower, with the biggest gains arriving when you stack the exhaust with headers, a high-flow Y-pipe, and a plenum spacer. Where the cat-back really earns its keep is character — the G35's V6 goes from muted to unmistakable.

The factory G35 exhaust is heavy mild steel and heavily muffled. A stainless cat-back like the three here drops several pounds of rotating-adjacent mass at the rear of the car and opens up the mid-range rasp the VQ is famous for. Because all three are cat-back systems, they leave your catalytic converters in place — keeping the car emissions-legal in most states and bolting on in your driveway in about an hour to 90 minutes with basic hand tools.

How we compared these three G35 exhausts

We ranked these cat-backs on four things G35 owners actually care about: material and build quality, sound character, fitment and tip style, and value including warranty. All three are proven, in-stock systems for the VQ35DE G35 at our Tampa, FL shop, and all three bolt to the factory hangers without cutting. Prices at NLP Performance span the roughly $1,280 to $2,180 range, so there is a clear entry point at every budget. Here is how each one stacks up.

What to expect: sound, weight, and power

All three of these G35 cat-backs are louder, lighter, and better-flowing than the factory system, but they trade off differently between noise and refinement. On the VQ35DE, expect the exhaust note to deepen noticeably at idle and to open into the VQ's trademark mid-range rasp as the tach climbs past 4,000 rpm. The stock system leans heavily on chambered, mild-steel mufflers that muffle exactly the frequencies enthusiasts want to hear; swapping to a mandrel-bent stainless straight-through design like the MagnaFlow, or the race-derived HKS Hi-Power muffler, lets those frequencies through.

Weight is the underrated win. The factory G35 exhaust is heavy, and a stainless or titanium-tipped cat-back can shed several pounds from the rear of the car — the HKS, with its titanium tips, is the lightest here. On the dyno, a cat-back-only change on a healthy VQ35DE usually reads as a 5-to-12 wheel-horsepower gain with a smoother torque curve above 5,000 rpm; the numbers grow once you add headers, high-flow cats or test-pipes, and a plenum spacer. Treat the cat-back as the foundation of a bolt-on package, not a standalone power part, and you will set the right expectations.

HKS Dual Hi-Power Titanium Tip — best overall

The HKS Dual Hi-Power is the enthusiast's choice for the G35, pairing SUS304 stainless tubing with HKS's signature burnt-titanium tips and the most aggressive tone of the trio. It is the priciest system here at about $2,180, but it is also the lightest-feeling and the loudest at wide-open throttle — a genuine race-bred design derived from HKS's Hi-Power muffler program. If your G35 is a weekend canyon or track car and you want it to announce itself, this is the one.

Borla Cat-Back (Coupe) — best value and warranty

The Borla Cat-Back is the smart daily-driver pick, delivering Borla's deep, aggressive-but-livable note out of T-304 aircraft-grade stainless and backing it with a warranty no one else in this test matches. Priced around $1,950, this 2-door system (part #140057) uses 2-1/4-inch tubing that splits into a dual rear exit capped by large 4-inch polished tips. Borla built it on the same platform as its wildly popular 350Z program, so the VQ35DE tuning is dialed — muscular under load, quiet enough to hold a conversation on the highway.

MagnaFlow Street Series — best budget

The MagnaFlow Street Series (part #16861) is the value leader, delivering MagnaFlow's signature deep, resonant VQ growl and dyno-proven flow for roughly $1,280 — hundreds less than the other two. It runs 2.5-inch mandrel-bent main piping into two straight-through mufflers, exiting through a dual driver-side rear exit with 3-inch polished, double-wall, angle-cut tips. It is aimed at the 2003–2006 G35 3.5L and backed by MagnaFlow's lifetime limited warranty, making it the easiest recommendation for a street car on a budget.

G35 cat-back exhaust comparison at a glance

Here is how the three G35 cat-back exhausts compare on the specs that drive the buying decision — material and piping, tip size, sound character, and price. Every kit below links straight to its product page at NLP Performance.

Which G35 exhaust is right for you?

Choose the HKS Dual Hi-Power if you want the loudest, most iconic setup and the titanium-tip look; it is the enthusiast and track pick at about $2,180. Choose the Borla Cat-Back if you daily-drive your G35 Coupe and want a deep, aggressive note that will not drone on the highway, plus a 1 Million Mile Warranty; at roughly $1,950 it is the best all-around value. Choose the MagnaFlow Street Series if you want the classic resonant VQ growl for the least money — around $1,280 with a lifetime limited warranty.

Whichever you pick, plan to pair it with a set of high-flow test-pipes or headers and a plenum spacer down the road to see the full VQ35DE power picture. On its own, any of these cat-backs is a clean, reversible bolt-on that transforms how the G35 sounds. Browse the full lineup in our performance exhaust collection, and our Tampa team can confirm coupe-versus-sedan fitment before you order.

Installing a G35 cat-back exhaust at home

Installing a cat-back on the 2003–2007 G35 is a straightforward driveway job that most owners finish in about one hour to 90 minutes. Because all three systems bolt to the factory hangers, there is no cutting or welding required for a standard install. Get the car safely in the air on a lift or jack stands, then work back to front so the new system hangs correctly before you tighten anything.

Soak the factory clamp and flange bolts with penetrating oil first — two-decade-old exhaust hardware is often rust-welded, and a stripped stud is the one thing that turns an easy job into a long one. Support each section as you remove it, transfer the rubber isolators to the new hangers, and hang the replacement mufflers loosely. Once everything is on the car, align the tips evenly in the valance, then torque the clamps from front to back. Leave 10 to 15 minutes for a heat cycle and re-check the clamps after your first drive; a quick snug-up prevents rattles and leaks down the road.