Introduction: Why Upgrade the Intercooler on Your Genesis G70?

The Genesis G70’s 2.0T or 3.3T engine delivers impressive power from the factory, but like all turbocharged vehicles, it is highly sensitive to intake air temperature. Hot air from the turbocharger robs power and increases the risk of knock, forcing the ECU to pull timing. The factory intercooler is adequate for daily driving in moderate climates, but it becomes a bottleneck under sustained hard driving, track use, or in hot weather.

Upgrading to a Mishimoto intercooler directly addresses this weak point. Their direct-fit unit features a larger bar-and-plate core, cast aluminum end tanks, and increased internal volume — all designed to reduce pressure drop while significantly lowering intake air temperatures. The result is more consistent power delivery, reduced knock retard, and greater tolerance for aggressive tunes or higher boost levels.

This guide walks you through a complete DIY installation of the Mishimoto intercooler on a Genesis G70. With basic hand tools and a few hours, you can achieve professional-grade results at home. We cover everything from the tools you will need to the final test drive. This project is rated intermediate — you should be comfortable working with plastic trim, clamps, and basic fasteners.

Tools and Materials Needed

Before beginning, gather the following items. The Mishimoto kit comes with the intercooler and mounting hardware, but you will need common tools and some consumables.

  • Mishimoto intercooler kit (part number MMINT-G70-20 or MMINT-G70-33 depending on engine).
  • Socket set — 10mm, 12mm, 13mm, 14mm, and 17mm sockets are most used.
  • Combination wrenches — same sizes as sockets.
  • Torque wrench (1/2-inch drive, capable of 20–100 ft-lbs).
  • Flathead screwdriver — for prying clips and trim.
  • Phillips screwdriver — for small screws (e.g., grille clips).
  • Ratchet straps or zip ties — to secure the front bumper when partially removed.
  • Coolant — only if you choose to drain the intercooler circuit (rarely necessary, but recommended if you disconnect the water-to-air heat exchanger on the 3.3T model).
  • Shop towels and gloves — for cleaning and protection.
  • Safety glasses — always wear them when working under a car or near pressurized coolant.
  • Floor jack and jack stands — optional but helpful for bumper removal clearance.

Preparation: Workspace and Safety

Park the Genesis G70 on a level surface. If you need extra space to work under the front of the car, safely raise it on jack stands and remove the front wheels — this gives you access to the wheel well fasteners and makes bumper removal easier. Allow the engine to cool completely if you have driven recently; the intercooler piping and radiator can be hot.

Disconnect the battery negative terminal as a general safety precaution, especially if you plan to disconnect any electrical connectors on the front of the car (e.g., ambient temperature sensor, fog lights). Wait at least 5 minutes before proceeding to allow the airbag system to discharge.

Step-by-Step Installation

Step 1: Remove the Front Bumper Cover

The Mishimoto intercooler mounts in the stock location behind the front bumper. The bumper cover must be removed to access the fasteners holding the factory intercooler. This process is straightforward but requires patience with plastic clips.

  1. Open the hood and remove the plastic cover at the top of the radiator support (if equipped) — it is held by 10mm bolts and clips.
  2. Remove the two 10mm bolts at the top of the bumper cover, located under the hood just behind the grille.
  3. Inside each front wheel well, remove the screws and push-pin clips that secure the bumper cover to the fender liner. There are usually 2–3 screws and 1–2 clips per side. Use a Phillips screwdriver and a trim tool or flathead to pry the clips.
  4. Under the front lip of the car, remove the 12mm bolts and plastic push pins holding the lower part of the bumper cover.
  5. Once all fasteners are removed, have a helper support the bumper cover while you disconnect the fog light connectors (if equipped) and the ambient temperature sensor connector on the driver side (usually a small plug with a locking tab).
  6. Carefully pull the bumper cover straight off the car — it hangs on plastic guides at the top corners. Set it aside on a soft blanket or towels to avoid scratching the paint. Use ratchet straps or zip ties to hold it loosely to the tow hooks or lower control arms if you prefer to leave it connected by the fender liners.

Tip: Label the fasteners by location as you remove them — the bumper reinstallation will go much faster if you know which screws go where.

Step 2: Disconnect the Stock Intercooler

With the bumper cover removed, the stock intercooler is fully visible. On the G70 2.0T, it is a single air-to-air unit mounted directly in front of the radiator. On the 3.3T, there is also a secondary water-to-air intercooler for the twin-turbo system — the Mishimoto kit replaces only the main air-to-air intercooler (the front mount). The following steps apply to both.

  1. Locate the charge air inlet and outlet hoses on the driver and passenger sides of the intercooler. They are held by spring clamps or worm-gear clamps. Loosen each clamp with a flathead screwdriver or a 7mm socket, then slide the hoses off the intercooler ports. Have shop towels ready to catch any residual oil or coolant that may drip from the hoses.
  2. If your G70 is equipped with an active grille shutter system (common on later models), you may need to disconnect the actuator connector and remove the shutter assembly from the back of the intercooler. This involves prying two small clips and sliding the shutter unit out. Keep track of the hardware.
  3. Remove the two 12mm bolts on each side that secure the intercooler to its brackets — one bolt at the top mounting ear and one at the bottom. The intercooler will now be free.
  4. Carefully lower the stock intercooler out of the car through the bottom opening. Watch for the rubber isolator pads — they often stick to the brackets. Retrieve them as you may reuse them or the Mishimoto kit will include new ones.

Note: If you own a 3.3T model and plan to keep the secondary water-to-air cooler, you do not need to drain or disturb that system. Only the main front-mount intercooler is being replaced.

Step 3: Install the Mishimoto Intercooler

Before installing the new intercooler, test-fit it in the vehicle with the brackets supplied in the kit. Mishimoto includes a detailed instruction sheet with torque specifications — refer to that for exact fastener sizes.

  1. Slide the Mishimoto intercooler into the opening, tilting it slightly to clear the radiator support brackets. It should fit snugly in the stock location.
  2. Install the four mounting bolts (two per side) through the provided bushings or rubber isolators. Tighten to 15–20 ft-lbs using a torque wrench. Do not overtighten as the aluminum end tanks can distort if excessive force is applied.
  3. Reinstall the active grille shutter assembly (if applicable) on the back of the Mishimoto intercooler. The shutter unit bolts to the same threaded holes on the intercooler core. Use the original hardware.
  4. Connect the charge air hoses to the Mishimoto intercooler ports. The Mishimoto unit uses the same inlet and outlet sizes as stock, so the hoses should slide on easily. Tighten the clamps to 5–7 ft-lbs (or hand-tighten worm-gear clamps to secure). Double check that the hoses are fully seated — the clamp should be positioned over the barbed section of the port.
  5. Inspect the piping for any kinks or misrouting. Make sure the hoses are not rubbing against the radiator or frame.

If your G70 has a water-to-air intercooler system: The Mishimoto intercooler is air-to-air, so it completely replaces the front-mount section. The secondary water-to-air cooler behind the engine on the 3.3T remains untouched. There is no need to bleed coolant from the intercooler system unless you accidentally disconnected a coolant line — in that case, use the correct OEM coolant and bleeding procedure (refer to the service manual).

Step 4: Reattach the Front Bumper Cover

Before refitting the bumper, verify that all plugs are secure, all clamps are tight, and no tools are left in the engine bay or behind the intercooler.

  1. Have a helper hold the bumper cover in position. Reconnect the fog light connectors and ambient temperature sensor. Push them in until you hear the locking click.
  2. Align the top edge of the bumper cover with the hood latch support hooks. Push inward until the plastic guides engage.
  3. Starting from the top center, install the 10mm bolts that secure the bumper cover to the radiator support. Tighten to 8–10 ft-lbs.
  4. Install the lower edge bolts and push pins under the front lip. Work from the center outward to ensure proper alignment.
  5. Reinstall the wheel well screws and clips. Use a trim tool to push the push pins fully home — a rubber mallet works well if needed.
  6. Reinstall the plastic cover above the grille (if removed).

Check: Step back and inspect the gaps between the bumper cover and the headlights, fenders, and hood. The G70’s panel gaps should be even; if they are not, loosen the top bolts and adjust the bumper cover slightly before retightening.

Step 5: Final Checks and Test Drive

Reconnect the battery negative terminal. Perform a thorough visual inspection before starting the engine:

  • Check that all intercooler air intake hoses are secure and not contacting the radiator, fan, or belts.
  • Inspect the lower bumper area for any loose clips that could cause rattles.
  • Look for any oil or coolant drips from the intercooler connections (loose clamps).

Start the engine and let it idle for 2–3 minutes. Turn on the A/C and let the cooling fan cycle a few times — listen for any abnormal sounds from the fan hitting the intercooler or shroud. If everything is quiet, take the car for a short drive in a low-stress environment.

Monitor the live data on your OBD2 scanner if you have one. You should see intake air temperatures (IAT) drop by 20–40°F (11–22°C) compared to stock under similar conditions — especially after a pull. The Mishimoto intercooler’s larger core mass also recovers temperature faster when you are cruising. Over the next week, pay attention to how the car feels: less heat soak on hot days, more consistent power when entering highway ramps, and less perceived pulling of timing under hard acceleration.

Performance Gains and Why Mishimoto

The benefits of a larger intercooler go beyond raw horsepower numbers. Cooler intake air reduces the likelihood of engine knock, allowing the factory ECU to retain its target ignition timing, and in some cases, even advance it. Many G70 owners report a reduction in knock correction events after the installation — that alone can improve power delivery and protect the engine on high-boost days.

Mishimoto’s intercooler is built with a bar-and-plate core (as opposed to the factory’s tube-and-fin design). This construction provides superior heat rejection and lower pressure drop. The cast aluminum end tanks flow more evenly to the core, further reducing turbulence. While some competitors offer cheap intercoolers that can actually restrict airflow, Mishimoto backs their product with a lifetime warranty and track-proven engineering. For a 350–400 wheel horsepower build (stock block with bolt-ons and a tune), this intercooler is more than sufficient — some users have even pushed it to 500+ whp with upgraded turbos.

When to Tune

After installing the Mishimoto intercooler, you do not have to tune the car — the stock ECU will adapt to the cooler air by pulling less timing. However, to fully exploit the increased thermal capacity, a custom tune from a reputable speed shop (e.g., Lap3, SXTH Element, or BTR) can raise boost targets and optimize fuel delivery. The intercooler becomes a prerequisite for any serious power upgrade; without it, a tune on a hot track day would quickly lead to knock and reduce power.

Common Pitfalls and Troubleshooting

  • Bumper fitment: If the bumper cover does not align properly after reinstallation, check that the lower lip brackets are not bent. The Mishimoto intercooler sits in the same envelope as the stock unit, so fitment should be identical — if you force the bumper, you may have a plastic guide trapped behind the core.
  • Clamp placement: Ensure air intake hoses are pushed fully onto the intercooler ports before tightening. A hose that slips off under boost will cause a massive boost leak and lean condition.
  • Heatsoak from A/C condenser: The Mishimoto core is thicker than stock, so you may notice slightly higher A/C pressures on hot days in stop-and-go traffic. This is normal for any upgraded front-mount intercooler. Some owners choose to add a lightweight aluminum radiator or perform a coolant system overhaul to balance temperature.

External Resources

Conclusion

Installing a Mishimoto intercooler on your Genesis G70 is one of the most effective modifications you can perform. It directly attacks the root cause of power loss on hot days — high intake air temperatures. By following this step-by-step guide, you can complete the job in an afternoon with basic tools and realize immediate improvements in throttle response and knock resistance.

Whether you are preparing the car for a new tune or simply want to protect your engine during summer driving, the Mishimoto intercooler is a worthwhile investment. Enjoy cooler air, more consistent power, and the satisfaction of a job well done.