Why Upgrade to the Turbonetics T66 Turbo?

The Turbonetics T66 turbocharger has earned a reputation as a reliable, high-performance upgrade for the RSX chassis, particularly when targeting 400–550 wheel horsepower on the K20A and K20Z engines. Unlike smaller frame turbos that choke at higher RPM, the T66’s 66mm compressor wheel moves a substantial volume of air without sacrificing mid-range punch. This turbo is well-suited for street-driven RSXs that also see track days or roll racing events.

Key reasons RSX owners choose the T66 include:

  • Proven Power Ceiling: With proper fueling and exhaust, the T66 supports over 500 whp on a built block, while remaining daily-drivable at lower boost levels.
  • Fast Spool for Its Size: Thanks to a billet compressor wheel and a .68 or .81 A/R turbine housing, the T66 reaches full boost by 3,800–4,200 RPM on the 2.0L K-series, which is impressive for a 66mm unit.
  • Robust Construction: Turbonetics uses fully CNC-machined components and a journal bearing center section (or optional ball bearing), ensuring long service life when properly lubricated.
  • Excellent Support Community: The RSX community has extensive tuning data for the T66, making it easier to dial in your setup with calibration software like Hondata KPro, KTuner, or FlashPro.

For a detailed overview of the T66’s compressor maps and sizing recommendations, consult the official Turbonetics website.

Preparation: Tools, Parts & Engine Health

Proper preparation is critical to a trouble-free installation. Rushing the job can lead to boost leaks, oil starvation, or even catastrophic engine failure. Below is an expanded checklist.

Engine Prerequisites

Before bolting on a T66, ensure your RSX’s bottom end can handle the extra stress. For power levels above 350 whp, forged pistons and rods are strongly recommended. Even at lower boost, a healthy K-series with fresh timing chain, valve seals, and a compression test showing 180–220 psi per cylinder is ideal. Replace any worn motor mounts – the torque from 400+ whp can tear factory rubber mounts apart.

Required Parts List

  • Turbonetics T66 turbocharger – choose your turbine housing AR (0.68 for quicker spool, 0.81 for top end power)
  • Turbo manifold – cast or tubular, T3/T4 flange. Ensure it clears the brake master cylinder on the RSX
  • Intercooler and piping – a bar-and-plate core rated for 500+ hp, 2.5” or 3” piping depending on target power
  • Oil feed & drain lines – -4AN feed line from a port on the block or head, -10AN drain to the oil pan
  • Boost controller – manual (like Hallman) or electronic (like BoostController or AEM)
  • Fuel system upgrades – larger injectors (1000cc min for pump gas, 1300cc+ for E85), and a fuel pump (Walbro 450 or AEM 320)
  • Engine management – Hondata KPro (for 02-04 RSX) or FlashPro (for 05-06 RSX) is mandatory for tuning
  • Wideband oxygen sensor – to measure air-fuel ratio during tuning
  • Heat management – turbo blanket, manifold wrap, and heat shielding for the ABS unit and wiring harness

Tool List

  • Metric socket set (10mm, 12mm, 14mm, 17mm, 19mm) with extensions
  • Torque wrench (ft-lb and in-lb ranges)
  • Oxygen sensor socket for removing pre-cat sensor
  • Hardline cutter and AN wrenches for oil/water lines
  • Thread sealant or Teflon tape for brass fittings
  • Booster pack or battery maintainer to keep electrical stable during work

Step-by-Step Installation Guide

These instructions assume the RSX is on jack stands with the battery disconnected. Always reference the service manual for factory torque specs.

1. Remove the Stock Exhaust Manifold and Intake

Unbolt the factory exhaust manifold – on the RSX there are eight 10mm bolts connecting it to the cylinder head. You’ll also need to disconnect the oxygen sensors and the catalytic converter. Remove the intake manifold if you plan to replace it or if the intercooler piping requires aftermarket intake manifold clearance. Inspect the threads in the cylinder head for any galling; chase with a tap if needed.

Tip: Soak exhaust manifold studs with penetrating oil the night before to prevent breakage.

2. Install the Turbo Manifold (Cast or Tubular)

Choose a manifold designed for the RSX’s K-series engine that positions the turbo for good fitment. Many quality options exist from Full-Race, Revival Motorsport, or Synapse Motorsport. Apply a light coat of anti-seize on the manifold studs. Torque the manifold nuts in a cross pattern to 18–22 ft-lb. If using a tubular manifold, ensure no wastegate routing interferes with the cam gear cover.

3. Mount the Turbonetics T66 Turbo

Using a new gasket between the manifold and turbo, install the T66. Rotate the compressor housing as needed for intake piping orientation (usually facing the passenger side on the RSX). Tighten the V-band or four-bolt clamp to spec. Be careful not to drop any hardware into the engine bay – tape a rag over the intake ports if necessary.

4. Connect Oil Feed and Return Lines

Use an oil feed line from the cylinder head port (near the cam gears) or from a sandwich plate in the oil filter housing. Require a restrictor if using a journal bearing turbo – Turbonetics typically recommends a 0.040″ restrictor orifice. The -10AN drain line must have a gravity-fed slope downward to the oil pan; install a bung in the pan above the oil level line. Pressure test the oil system by spinning the engine with the fuel pump fuse removed until oil seeps from the feed line.

Critical: A poorly routed drain line will flood the turbo seals causing smoke and oil consumption. Keep the drain at least ½” per foot downward angle.

5. Install the Intercooler and Piping

Mount a bar-and-plate intercooler in the front bumper beam. For the RSX, a 24″x12″x3″ core fits well and supports 500+ hp. Use silicone couplers and T-bolt clamps. If retaining AC, trim the plastic shroud minimally to clear piping. Size the piping: 2.5” is typical for street setups, 3″ for high flow blowers.

Ensure all joints are leak-free – a boost leak test (2‑psi with a pressure tester) is highly recommended before fire-up.

6. Upgrade Fuel System

Replace the fuel pump: drop the rear bench and remove the access panel. Swap the pump assembly with a Walbro 450 or similar. Install the larger injectors (top feed for K-series) with new o-rings. Reprogram the ECU for the new injector dead times. If running E85, also upgrade the fuel lines to PTFE (Teflon) to withstand ethanol’s corrosive nature.

7. Install the Boost Controller and Engine Management

Mount an electronic boost controller in the cabin or engine bay, with a vacuum line to the wastegate actuator. Wire the controller to a switched 12V source. Then load a base tune onto the Hondata KPro or FlashPro: start with conservative ignition timing (around 18–20 degrees at peak torque) and target lambda of 0.80 (11.5:1 AFR) under boost. Do not attempt full boost before verifying fuel pressure and no knock.

8. Final Checks & Start-Up

Double-check every bolt: turbo bolts, manifold bolts, intercooler clamps, oil line fittings, and battery terminal. Reinstall the factory heat shields or aftermarket heat wrap near the brake lines. Refill engine oil with a high-quality 5W-40 or 10W-40 synthetic. Crank engine without spark plugs (fuel pump fuse removed) to build oil pressure. Reinstall plugs, reconnect everything, and start.

Let idle for 10 minutes to circulate oil through the turbo. Check for leaks – if oil drips from the turbo drain, you need a better slope or larger drain tube.

Tuning the Turbonetics T66 RSX

Installation is only half the battle; proper tuning unlocks the T66’s potential. Here’s what the calibration process involves:

  • Base map creation: Start with a safe map from a known tuner. Many community members share base maps for RSX with 1000cc injectors and T66 – but always verify with a wideband.
  • Fuel tuning: Use manual mode on KPro to dial in each fuel column. For a 400 whp target, expect pulse widths around 12–14ms at 8000 rpm. Blend E85 to increase octane and reduce intake temps.
  • Ignition tuning: K-series engines respond well to moderate timing – around 22 degrees at peak torque tapering to 12–14 degrees near redline. Watch for knock retard; retune timing in affected zones.
  • Boost control: Electronic solenoid duty cycles. Start at 15 psi base boost (wastegate spring), then use the controller to ramp to 22–25 psi. Monitor fuel pressure drop; you may need a boost referenced fuel pressure regulator.
  • Dyno tuning recommended: For maximum safety and power, visit a professional tuner experienced with Hondata. They can dial in cam angles, VTEC crossover, and knock sensitivity in real time.

Expected Power Gains & Dyno Results

Real-world results from RSX owners show the T66’s impressive curve. Below is a typical dyno plot summary on pump gas (91 octane):

  • 300 whp @ 10 psi: conservative tune with stock block and basic intercooler – safe daily driver
  • 420 whp @ 18 psi: typical build with forged rods, pistons, 1000cc injectors, and E85 support. Torque peaks at 340 lb-ft at 4800 rpm
  • 500+ whp @ 25 psi: built motor with aggressive cams, ported head, and 1300cc injectors on E85 – borderline for stock transmission

On the street, the T66 spools fast enough to make passing effortless from 2500 rpm, with the real rush beginning at 3500 rpm and pulling hard past 8000 rpm. The RSX’s lightweight chassis (around 2,800 lbs) means a 400 whp car runs low 11-second quarter miles with proper traction.

Long-Term Considerations & Maintenance

To maximize the T66 turbo’s lifespan and your RSX’s reliability:

  • Oil changes every 3,000 miles with a high-zinc synthetic (like Rotella T6 or Motul) – turbo bearings wear faster with old oil
  • Let the turbo cool down after spirited driving – idle for 2 minutes before shutdown to prevent coking
  • Inspect wastegate and BOV springs – they settle over time; check boost creep seasonally
  • Replace O-rings and gaskets – the intercooler couplers and turbo inlet gasket can leak after 10–20k miles
  • Monitor fuel trims regularly – KPro allows datalogging of long term fuel trim; if it swings beyond +/-10%, check for vacuum leaks

For community support and build threads, the ClubRSX forums have an extensive forced induction section with T66-specific logs.

Where to Buy the Turbonetics T66 and Supporting Parts

Purchasing from reputable suppliers ensures you get genuine Turbonetics products and avoid counterfeits. Recommended vendors:

  • Direct from Turbonetics: Authorized dealer listings and kit bundles available on their site
  • Performance parts retailers: Summit Racing, JEGS, or Maperformance – check for genuine T66 seals
  • Used market (with caution): Check the part number and shaft play before buying used; new or OEM-remanufactured is best for reliability

Also consider a complete turbo kit – companies like Injector Dynamics offer plug-and-play injectors for the K-series that match the T66 fuel requirements without modifications.

Conclusion

The Turbonetics T66 turbo upgrade for the Acura RSX delivers a dramatic power increase while remaining civilized for daily driving. With the correct preparation, careful installation, and professional tuning, you can unlock 400–500 reliable wheel horsepower – enough to run with high performance sports cars costing three times as much. Whether you’re building a street machine or a weekend track toy, the T66 is a proven choice that has been tested in countless RSX builds. If you’re not comfortable tackling the wiring or fuel system yourself, enlist the help of a reputable shop that understands Hondata KPro – it’s money well spent to protect your investment and ensure the turbo performs as intended. Get ready to enjoy a completely transformed driving experience.