Unlocking serious horsepower from a Nissan 370Z—pushing past the 400-wheel horsepower mark—transforms an already capable sports car into a real street predator. While the VQ37VHR engine is a strong foundation, achieving that triple-digit gain typically requires a carefully selected combination of bolt-on parts and internal modifications. Two of the most effective upgrades for the money are a high-flow exhaust system and a set of performance camshafts. The Motordyne exhaust system and aftermarket cams are a proven recipe, but the costs can vary significantly depending on labor rates, supporting modifications, and tuning choices. This expanded breakdown gives you a realistic, line-item view of what to budget for, what hidden expenses might pop up, and how to make smart decisions along the way.

Understanding the Upgrades Required for 400+ Wheel Horsepower

The factory 3.7-liter V6 in the 370Z produces around 332 horsepower at the crank. To reach 400+ at the wheels (which translates to roughly 470-500 at the crank, depending on drivetrain loss), you cannot simply slap on an exhaust and call it a day. The combination of a free-flowing exhaust and upgraded cams addresses two critical bottlenecks: the engine’s ability to expel exhaust gases efficiently and its ability to draw in a larger air/fuel charge. However, these two mods work best when paired with other supporting parts like long-tube headers, a cold air intake, and a proper ECU tune. This cost breakdown focuses on the exhaust and camshafts as the centerpieces, but we will also cover the almost mandatory supporting modifications that ensure you actually hit your horsepower target.

Breaking Down the Motordyne Exhaust System Costs

What Makes Motordyne Unique

Motordyne Engineering is a premier name in the Nissan VQ community, known for precision-crafted, dyno-proven exhaust components. Their ShockWave cat-back exhaust system features a Helmholtz resonator that cancels out drone frequencies while maintaining a deep, aggressive tone. For the 370Z, Motordyne offers multiple configurations: cat-back, axle-back, and a full system including ART pipes (high-flow catalytic converters or test pipes). The goal is to drastically reduce backpressure while keeping the sound track-appropriate.

Component Pricing

  • Motordyne ShockWave Cat-Back Exhaust: $1,500 – $2,000 (depending on tip options, polished vs. brushed finish, and current market pricing)
  • Motordyne ART Pipes (High-Flow Cats or resonated test pipes): $600 – $900 (required for maximum flow, but consider your local emissions laws)
  • Motordyne Y-Pipe (if not included in cat-back): $300 – $500
  • Hardware and gaskets: $50 – $100

Labor Costs for Exhaust Installation

Installation of a cat-back system is a doable DIY job for an intermediate mechanic, but many prefer a shop to ensure proper alignment and no exhaust leaks. If you also install ART pipes, the O2 sensor bungs and the tight space around the transmission make it a bit more involved. Expect:

  • Cat-back only (DIY): $0 (your time)
  • Cat-back only (shop labor): $150 – $350 (1.5–2 hours)
  • Full exhaust including ART pipes (shop labor): $300 – $600 (3–4 hours)

Note: Some shops charge a flat rate for exhaust work, while others bill hourly at $100–$150 per hour. Always ask for a quote before dropping the car off.

Performance Camshafts for the VQ37VHR Engine

Why Cams Matter

Factory camshafts on the 370Z are designed for a balance of emissions, idle quality, and broad power. Aftermarket cams with increased duration and lift allow more air to enter the cylinder, especially in the high-RPM range. This is where the big horsepower gains live. However, cam install on a VQ37 is a major engine-out procedure (on earlier models, it can be done in-car but is extremely tight). The cost of the camshafts themselves is just part of the equation.

Camshaft Kit Pricing

  • Stage 1 or mild street cams (e.g., Tomei, BC, JWT): $800 – $1,200 (includes camshafts only)
  • Stage 2 or aggressive cams: $1,200 – $1,800
  • Cam sprockets, timing chain tensioners, gasket set (highly recommended to replace during install): $300 – $600
  • Valve springs and retainers (upgrade strongly recommended for aggressive lift cams to prevent valve float): $400 – $800

Labor Costs for Cam Installation

This is the most expensive labor item on the list. The timing cover must be removed, valve covers removed, chains and tensioners replaced, and cams swapped. A competent shop will charge 10–15 hours for this job. At $100–$150/hour, you’re looking at:

  • Labor for cam installation (including timing chain, gaskets, and valve spring upgrade if applicable): $1,000 – $2,000
  • Dyno tuning after cam install (mandatory!): $400 – $700

Pro tip: Some tuners offer a package deal if you buy the cams and tune from them, potentially saving a few hundred dollars.

Total Cost Breakdown for the Core Upgrades (Exhaust + Cams)

Here is the combined estimate for the Motordyne exhaust system and performance cams, including all labor and recommended supporting parts.

ItemLow EstimateHigh Estimate
Motordyne Cat-Back + ART Pipes$2,100$2,900
Exhaust installation labor$300$600
Performance cams (Stage 1)$800$1,200
Cam sprockets, gaskets, springs$700$1,400
Cam installation labor$1,000$2,000
Dyno tuning$400$700
Total$5,300$8,800

As you can see, the realistic cost for these specific upgrades is significantly higher than the earlier estimate of $3,800–$4,800 once you factor in cam hardware and tuning. That earlier number likely assumed DIY labor and no valve spring upgrade. Use these numbers as your baseline.

Additional Supporting Modifications (Almost Mandatory for 400+ WHP)

Simply installing cams and an exhaust will not guarantee 400 wheel horsepower. You will need to address the intake side, fueling, and engine management. Here are the most common supporting mods and their costs.

Cold Air Intake & Plenum Spacer

  • Cold air intake (e.g., Stillen, Injen, Z1): $400 – $700
  • Plenum spacer (to increase intake volume): $200 – $400
  • Installation labor (if not DIY): $100 – $200

Headers

Factory exhaust manifolds are restrictive. Long-tube headers are preferred for big NA power.

  • Long-tube headers (e.g., PPE, Z1, AAM): $1,000 – $1,800
  • Installation labor (moderate difficulty): $400 – $800

Upgraded Injectors & Fuel Pump

At 400+ wheel horsepower, the factory fuel system may run out of capacity. Many builds upgrade to 550cc or larger injectors and a higher-flow fuel pump.

  • Fuel injectors (set of 6): $500 – $1,000
  • Fuel pump (drop-in or in-line): $200 – $500
  • Installation labor: $200 – $400

ECU Tuning & Flex Fuel (E85)

E85 ethanol fuel provides additional knock resistance and can significantly increase power with proper tuning. It often pushes a cammed 370Z well past 420 wheel horsepower.

  • Uprev or ECUTEK license + tune: $600 – $1,000
  • Flex fuel sensor and wiring kit: $200 – $400
  • Dyno tuning session (if not already accounted): $400 – $700

Oil Cooler and Drivetrain Upgrades

With significantly more power, heat management becomes critical. The factory oil cooler is marginal for track use; upgraded cooling is recommended. Also, the factory clutch will slip around 400 wheel horsepower.

  • Setrab or similar oil cooler kit: $400 – $800
  • Performance clutch and flywheel: $800 – $1,500
  • Clutch installation labor: $600 – $1,000

Important note: If you are doing the cam install (engine-out), it is the perfect time to also replace the clutch and install the oil cooler, saving future labor costs. Plan accordingly.

Where Can You Potentially Save Money?

  • DIY installation: Exhaust and intake are beginner-friendly. Cam installation is advanced but possible with a solid service manual, special tools (cam locking tool, timing chain tensioner tool), and a lift rental. Budget $200-$400 for tool purchases/rentals.
  • Buy used parts: Motordyne exhausts hold their value, but you can sometimes find them on forums like My350Z.com or Facebook Marketplace for 30-40% off retail. Cams are also available used, but inspect for wear and include timing gear.
  • Bundle deals from vendors: Companies like Z1 Motorsports or AMS Performance sometimes offer packages that combine cams, valvetrain, and tuning at a discount.
  • Skip the valve spring upgrade for mild cams: If you choose Stage 1 cams with modest lift (below 0.400”), you can often reuse factory springs safely, saving $400-$800. Confirm with your cam manufacturer first.
  • Do your own dyno tuning (if you are an expert): This is not recommended for most owners. A bad tune can destroy your engine. Professional tuning is worth every penny.

Expected Horsepower Gains: Dyno Reality Check

What numbers should you realistically expect? Here is a rough guide based on common forum results and dyno tests:

  • Motordyne cat-back + ART pipes + intake + tune: ~330-350 wheel horsepower (gain of 20-40 WHP over stock).
  • Add long-tube headers and plenum spacer: ~370-390 wheel horsepower.
  • Add Stage 1 cams + upgraded valvetrain + full exhaust + headers + E85 tune: ~410-430 wheel horsepower. This is the 400+ WHP target.
  • Aggressive Stage 2 cams + full bolt-ons + E85: ~440-460 wheel horsepower, but with a lumpy idle and reduced low-end torque.

These numbers assume a Dynojet or Mustang dyno using SAE correction and a competent tuner. Factory 370Z drivetrain loss is roughly 15-18%. So 410 wheel horsepower equals about 490-500 crank horsepower.

Other Critical Considerations Before You Start

Emissions and Street Legality

Motordyne ART pipes with high-flow catalysts may or may not pass visual inspection in strict states (California, New York). Test pipes are illegal on public roads everywhere. Cams alone do not affect visual inspection, but the tune may cause OBD readiness issues. Research your local laws before spending the money.

Engine Longevity and Maintenance

A well-built 400+ WHP VQ37 can remain reliable for daily driving if properly tuned and maintained. Oil changes become more critical (use high-quality synthetic every 3,000-4,000 miles). The upgraded valve springs and oil cooler are essential if you plan to track the car. Expect to replace spark plugs more often (every 15,000 miles) and clean the MAF sensors periodically.

Insurance and Resale Value

Some insurance companies will not cover heavily modified vehicles, or they may require a separate agreed-value policy. Also, modifications generally lower resale value unless you find a buyer who wants exactly your setup. Keep your stock parts to return the car to factory if needed.

Labor of Love: The Time Commitment

Even if you pay a shop for everything, expect the car to be out of commission for one to two weeks due to parts ordering, scheduling, and tuning. If you are doing the work yourself, budget two weekends for cam installation and an additional weekend for the exhaust and tune. Plan for delays and take your time.

Final Thoughts and Recommendations

Upgrading your Nissan 370Z to 400+ wheel horsepower using a Motordyne exhaust and performance cams is absolutely achievable, and the resulting driving experience is intoxicating. The total cost for just the exhaust and cams—including labor, tuning, and essential supporting hardware—ranges from roughly $5,300 to $8,800. That range does not include headers, clutch, or fuel system upgrades, which can push the total build cost to $10,000-$14,000 if you go all-in.

To avoid disappointment, do not skip the dyno tune, and do not cheap out on the valvetrain if you choose aggressive cams. Start with a solid plan, buy quality parts, and find a trusted shop that specializes in Nissan VQ engines. The end result—a snarling, high-revving naturally aspirated 370Z that pulls hard from 4,000 to 7,500 RPM—is worth the investment.

For further reading, check out Motordyne’s official product page for the latest pricing, and visit 370Z Forum for real-world build threads and dyno sheets. If you are thinking about taking the plunge, start saving now—the parts you want will probably sell out before you’re ready.