Introduction

Upgrading the intercooler on a VG30DETT engine is one of the most effective ways to reduce intake temperatures and maintain consistent power output under boost. The twin-turbo VG30DETT found in the Nissan 300ZX and early Infiniti J30 (non-US) is notorious for heat soak in traffic, especially with the factory side-mount intercoolers. A quality aftermarket unit like the Blitz front-mount intercooler kit dramatically decreases pressure drop and lowers intake air temperatures by up to 40°F under sustained load. This guide covers every step of the installation, from removing the stock side-mounts to securing the new piping and testing for leaks. Whether you’re a seasoned shade-tree mechanic or a first-time Z32 owner, following this procedure will ensure a clean, leak-free install that performs for years.

Tools and Materials Needed

Before you begin, gather all necessary tools and hardware. A complete install can be done in a weekend, but having everything on hand prevents frustrating trips to the hardware store.

  • Blitz front-mount intercooler kit (includes core, piping, couplers, clamps, and mounting brackets)
  • Metric socket set (10mm, 12mm, 14mm, 17mm)
  • Combination wrenches (10mm–17mm)
  • Flathead and Phillips screwdrivers
  • Trim removal tools (plastic pry bars for bumper/fascia clips)
  • Heavy-duty spring clamps or T-bolt clamps (if not included)
  • Silicone couplers and reducers (verify kit includes correct diameters)
  • Torque wrench (for mounting bolts and critical fasteners)
  • Ratchet strap or helper (to hold core in place while installing)
  • Heat-resistant tape or silicone wrap (for metal piping near radiator)
  • Jack and jack stands (if removing bumper lower trim)
  • Safety glasses and gloves
  • Soapy water or leak tester (for boost leak check)

Some installations may also require a Dremel or angle grinder for minor clearance modifications. Check the kit instructions before cutting metal.

Preparation and Safety

  1. Park on level ground and allow the engine to cool completely. The intercooler and charge pipes can be hot immediately after driving.
  2. Disconnect the battery negative terminal to prevent accidental sparks or short circuits while working near the radiator and fuse box.
  3. Drain coolant only if your kit interferes with the lower radiator hose or if you plan to replace the coolant. Many VG30DETT owners use this opportunity to flush the cooling system.
  4. Remove the front bumper fascia (on most Z32/300ZX models) to access the core area. This typically involves removing several Phillips screws along the top edge, a few 10mm bolts at the wheel wells, and plastic rivets underneath.
  5. Set the bumper aside safely – a towel on the ground works well to avoid scratching the paint.

If your vehicle is a right-hand-drive model or has additional AC ducting, refer to the Blitz kit’s specific notes. The general procedure remains similar.

Removing the Stock Intercoolers

The factory VG30DETT uses two side-mount intercoolers, one per turbocharger. They are located behind the front wheels, partially hidden by the inner bumper structure. Removal requires patience – the bolts can rust and access is tight.

Disconnecting Intake Ducting

  • Remove the intake pipe from each turbo compressor outlet to the stock intercooler inlet. Use a wrench on the 10mm clamp bolts – these are often spring-style.
  • Detach the outlet pipe (also called the throttle body pipe) from the intercooler to the balance tube or directly to the throttle body on later models.

Important: Mark which pipe is driver side vs. passenger side if they are different lengths. Some aftermarket kits reuse certain sections, but for a full FMIC upgrade you will discard all stock piping

Unbolting the Side-Mounts

  • Locate the two 12mm bolts holding each intercooler to the body. On the 300ZX, one bolt is at the top of the core, the other near the bottom bracket.
  • Use a wobble socket extension to reach the rear bolt on the passenger side – it’s blocked by the power steering reservoir.
  • Gently pry the intercooler free from its rubber grommet mounts. It may require a flat blade screwdriver to push the grommet out of the body.
  • Slide each stock intercooler out through the wheel well opening. You may need to turn it diagonally.

Once removed, inspect the stock units for oil residue or buildup. Clean any oily crankcase vapor residue from the nearby intake pipes to prevent oil from coating your new intercooler core.

Installing the Blitz Front-Mount Intercooler

The Blitz kit is designed to replace both side-mounts with a single larger core mounted behind the center bumper opening. This reduces piping length by as much as 60% and eliminates the hot-side piping that passes near the radiator.

Mounting the Core

  • Test-fit the Blitz core in the opening behind the bumper reinforcement bar. The core should sit level and centered with at least 1 inch of clearance from the radiator condenser.
  • Attach the supplied mounting brackets to the core first, then bolt them to existing holes in the crash bar or inner fender. You may need to enlarge holes with a round file.
  • Secure all bracket bolts to 12–15 lb-ft – over-torquing can strip the thin aluminum brackets.
  • Use a ratchet strap to hold the core steady while you adjust alignment. The core’s outlet should point slightly downward toward the throttle body side.

Routing the Piping

  • Most Blitz kits include two long charge pipes: one from the passenger-side turbo to the intercooler inlet, and one from the intercooler outlet to the throttle body.
  • Slide the pipes into position using the supplied silicone couplers and T-bolt clamps. Test-fit all connections before tightening.
  • For the cold-side pipe (outlet to throttle body), it typically runs along the front of the engine bay behind the headlight assembly. Use the supplied hangers or zip-ties to keep it away from the alternator and belt.
  • For the hot-side pipe (turbo to intercooler), it usually passes under the radiator core support. You may need to trim the plastic lower under-tray.

Modification note: Many VG30DETT owners find they need to grind 1/4 inch off the crash bar’s lower lip for the hot-side pipe to clear. Use a burr or angle grinder and repaint the bare metal with rust-inhibiting paint.

Connecting the Piping and Securing Connections

Improperly tightened charge pipes are the most common source of boost leaks after an intercooler upgrade. Take extra care at this stage.

Using Silicone Couplers and Clamps

  • Slide the T-bolt clamp onto the pipe, then install the coupler so it overlaps evenly on each side (1 inch minimum engagement).
  • Torque T-bolt clamps to 6–8 Nm (4–6 lb-ft) – hand-tight plus a half turn is usually sufficient. Over-tightening will cut into silicone couplers.
  • For spring-style clamps, check that they are fully seated in the groove of the connector bead.

Wrap any pipe that comes within 1 inch of the upper radiator hose with heat-resistant tape or reflective sleeve. The Blitz piping may route near the AC lines; use split loom conduit if directed by the kit manual.

Final Steps and Testing

Reassembly

  • Reinstall the front bumper fascia. Align the clips and screws; do not over-tighten plastic retainers.
  • Reconnect the battery negative terminal.
  • Refill coolant if drained, and burp the system according to Nissan service procedures.

Boost Leak Check

Before starting the engine, pressurize the system to about 15 psi using a compressor and a custom test cap on the throttle body elbow. Listen for hissing sounds and spray soapy water on all couplers. Bubbles indicate a leak. Tighten the clamp slightly and retest. If you do not have a pressure tester, start the engine and let it idle while you soap each connection – a rough idle or whistling can reveal leaks.

Test Drive

  • Take a short test drive under light load. Monitor boost pressure with a gauge (if equipped) to ensure it reaches the same level as before the upgrade.
  • After 10–15 minutes, check all clamps again – thermal expansion can loosen them initially.
  • Listen for any contact noise: piping that rubs the fan shroud or frame will wear through both the pipe and coupler over time.

Performance expectation: With a Blitz FMIC, you should see a 15–25°F reduction in intake air temperature at the top of a third-gear pull, with no boost drop across the core. If you also upgrade the turbos or increase boost, consider adding a external wastegate to manage the higher airflow.

After the intercooler is installed, consider these supporting modifications to maximize the gains:

  • Oil catch can – reduces oil vapor fouling the intercooler core.
  • Boost controller – the low-restriction intake lets turbos spool faster; adjustments prevent overboost.
  • Replace thermostat – cooler coolant helps keep intercooler temperatures down in traffic.
  • ECU retune – a FMIC changes airflow characteristics; a custom tune ensures the air/fuel ratio stays safe under boost.

Conclusion

Installing a Blitz intercooler on your VG30DETT is a high-impact upgrade that pays off immediately in lower intake temps and reduced lag. By following this step-by-step guide – from prepping the workspace to pressure-testing the final connections – you ensure the system works as intended without hidden leaks or clearance issues. The result is a cooler-running, more consistent engine that pulls hard lap after lap. For additional details, refer to the official Blitz intercooler product page and the Z1 Motorsports installation notes for specific VG30DETT fitment. For more general tuning advice, Concept Z Performance’s guide offers complementary tips on selection and ducting.