How to Build a 350Z / G35 for Time Attack, HPDE & Autocross
If you want a Z/G that’s fast, predictable, and reliable on track, your build order matters. This pillar guide walks through the highest-impact upgrades for time attack, HPDE, and autocross—with a suspension-first approach built around repeatability and real seat time.
You’ll also see a real-world example: Anthony Guarnieri’s Time Attack Infiniti G35 build (with TL-ONE coilovers), plus an advanced section outlining a VQ37VHR swap.
1) Choose Your Discipline (Time Attack vs HPDE vs Autocross)
“Track build” can mean three very different goals. Before you buy parts, decide what you’re optimizing for:
Time Attack
- Goal: lowest lap time
- Priorities: platform control, heat management, tire strategy, aero stability
- Common mistake: chasing horsepower before solving balance and repeatability
HPDE / Track Days
- Goal: repeatable sessions, safe progression, minimal downtime
- Priorities: cooling, braking consistency, predictable handling, alignment stability
- Common mistake: aggressive parts that reduce confidence and tire life
Autocross
- Goal: transient response and rotation in low-speed corners
- Priorities: quick weight transfer control, front-end bite, tire temperature management
- Common mistake: over-stiff setups that reduce grip on imperfect surfaces
2) The Build Philosophy: Reliability + Chassis Control First
The Z33/V35 chassis responds extremely well to a well-matched suspension system, good alignment, and strong braking— often delivering bigger lap-time gains than power mods alone.
The correct build order (for most drivers)
- Safety + maintenance (fluids, wheel bearings, bushings, fasteners)
- Suspension + alignment (coilovers, arms, corner balance)
- Brakes + tires (pads/rotors/fluid, tire strategy)
- Cooling (especially for repeatable sessions)
- Power (only after the car is stable and consistent)
If you’re building a Z/G for competitive use, treat consistency as a performance mod. A car that runs every session at 9/10ths beats a car that runs one flyer and overheats.
3) Suspension Setup
Suspension is where Z/G builds are made. This chassis can be very fast with the right balance, but it demands: correct spring rates, damping control, and alignment that matches the tire.
Start with a system, not just a part
- Coilovers matched to the car’s discipline
- Arms & adjustability to hold alignment at ride height
- Sway bars to fine-tune balance
- Corner balancing to maximize consistency
Recommended reading
- Best Coilover Spring Rates for Track vs Street (and Drift) — 350Z & G35
- What Is a True Rear Coilover, and Why It Matters on the 350Z/G35
- Monotube vs Twin Tube Coilovers for Track Use
- Track Alignment Basics for 350Z & G35
- Wheel and Tire Fitment guide for Z & G platforms
Baseline spring-rate options
Use these as a starting point, then tune balance with alignment, tire choice, sway bars, and damping. (For details and context, see the spring rate article linked above.)
| Use Case | Baseline Target | General Intent |
|---|---|---|
| Comfort / Performance Street | 14k Front / 6k Rear | Compliance + control |
| Street / Track | 16k Front / 7k Rear | Balanced dual-duty |
| Track / Race | 20k Front / 8k Rear | Platform support |
| Drift | 16k Front / 10k Rear | Rear consistency |
Product resource links
4) Brakes & Tires
Brakes and tires decide how long you can push—and how confidently you can repeat laps. A fast lap is meaningless if you can’t do it every session.
Brakes: build for heat
- High-temp brake fluid and proper bleeding routines
- Pad compound matched to vehicle weight and discipline
- Cooling and airflow matter as much as rotor size
Tires: the most important “mod” for lap time
- Pick tires based on discipline and temperature window
- Align the car around the tire (not the other way around)
- Track: consistency and heat tolerance matter
- Autocross: quick warm-up and response matter
5) Weight Reduction & Balance
Weight reduction is powerful, but only when done deliberately. Focus on: unsprung weight, front-to-rear balance, and corner weights.
High-impact priorities
- Wheels/tires (unsprung + rotational weight)
- Battery relocation and sensible interior reduction (discipline dependent)
- Corner balancing after ride height is finalized
Both the Z and the G are going to get more and more front-heavy as you strip out weight. It is important to be mindful of this - although Lower overall weight > Weight Distribution typically holds true.
6) Powertrain Strategy (Basic Builds)
Most Z/G builds get faster by improving stability and grip before adding horsepower. For HPDE and early time attack, prioritize reliability mods over peak output.
“Stage 1” powertrain priorities
- Cooling and heat management first
- Reliable fueling and consistent ignition under load
- Driveline health: mounts, diff condition, fluid strategy
Once the chassis is predictable, modest power becomes more usable—and easier to drive at the limit.
7) Driver Development & Data
The fastest “mod” is driver consistency. A predictable setup helps you improve faster and reduces tire/brake waste.
How to get quicker (without changing the car)
- Baseline laps + notes (what the car does in entry/mid/exit)
- One change at a time (alignment, tire pressure, damping)
- Track video + simple data to spot habits
8) Case Study: Anthony Guarnieri’s Time Attack Infiniti G35 (Real Build Example)
Anthony Guarnieri (@ag_g35) built his Infiniti G35 into a focused, repeatable Time Trial weapon—one that shows what happens when the chassis, braking, cooling, and aero all support each other instead of fighting for attention. At roughly 338whp / 270wtq and about ~3300 lbs with driver and full fuel, the car’s pace comes from balance and repeatability.
Build Snapshot
Power & Weight
- Output: 338whp / 270wtq
- Weight: ~3300 lbs with driver and full fuel
Engine
- Swap: VQ37VHR
- Guilty Garage 3" intakes
- Concept Z Performance lightweight flywheel and clutch + HRK CSC delete
- EcuTek tune
- ISR long tube headers
- GKTech swirl pot
- Koyorad oil cooler
- GReddy baffled oil pan
Suspension
- Coilovers: Thunder Lane TL-ONE
- Spring rates: 20k front / 8k true rear (Swift)
- GKTech control arms and chassis components
- Hotchkis front sway bar
Wheels
- Konig Hexaform 18x10.5 +18
Brakes
- Wilwood 6-piston front / 4-piston rear
- Carbotech XP20 (front) / XP10 (rear)
- Castrol SRF brake fluid
Drivetrain
- Tomei 1.5-way LSD
- 3.9 final drive
- 370Z axles and hubs
Interior & Safety
- Autopower 4-point roll bar
- RaceQuip containment seat and 6-point harnesses
- Halfway gutted interior
Aero
- Homemade wooden front splitter
- Nine Lives Racing swan neck 70" rear wing
- Duraflex front bumper
Why this build works
The TL-ONE setup (paired with 20k/8k Swift springs) supports platform stability under braking, transitions, and sustained cornering. The wider tire configuration and aero package benefit from a predictable chassis that can be driven at the limit repeatedly without “mystery behavior” from session to session.
Read the full build story here: Infiniti G35 Time Attack Build | Thunder Lane TL-ONE Coilovers
9) Advanced: Engine Swaps & VHR Swap Overview
This section is intentionally labeled advanced. Most drivers do not need an engine swap to get fast—especially early on. But once the chassis is sorted and you’re truly power-limited, swaps can make sense. The most effective swap that fits into popular Time Trial rulesets is the VQ37VHR swap. This motor shares the basic dimensions and mounting points with the car's original VQ35DE motor, so it is a very straightforward swap.
When an engine swap actually makes sense
- You can consistently use the current power level and want more on straights
- The chassis is stable and you’re limited by acceleration, not corner speed
- You have budget and time for integration and debugging (wiring, ECU, cooling, fuel)
Anthony’s “two-month” VHR swap (high-level recap)
- Trigger: the original DE motor failed after a weekend of knocking
- Upgrade path: sourced a complete VQ37VHR engine, transmission, and differential from a NISMO 370Z
- Execution: built a plug-and-play style wiring solution to streamline integration
- Timeline: completed from teardown to track-ready in ~two months, debuting at HyperFest Time Trial in May
The key takeaway: swaps should be an evolution—not a shortcut. If your suspension, brakes, tires, and cooling aren’t already solid, more power usually makes the car harder to drive and harder to keep alive.
FAQ
Should I build my 350Z/G35 for suspension before adding power?
In most cases, yes. Suspension, brakes, and tires typically deliver the biggest performance gains sooner than peak power, while improving confidence and reliability.
What’s the best first upgrade for a Z/G track build?
A coilover system matched to your discipline plus a real alignment plan. This improves balance, grip, and repeatability immediately.
Do I need an engine swap (like a VHR swap) for time attack?
Not at the beginning. Most drivers gain more from corner speed, braking stability, tire strategy, and consistency. Treat swaps as an advanced phase once the chassis is sorted.
What’s different about autocross setups?
Autocross rewards response and rotation in tight transitions. The “best” setup often differs from road course priorities, especially in how you trade compliance for responsiveness.
