APS Stealth Intercooled Twin Turbo Pontiac GTO/Holden Monaro




APS Stealth Intercooled Twin Turbo Pontiac GTO

Since the release of the LS1 engine in the Pontiac GTO, the hearts of performance enthusiasts pounded for an engine enhancement system that would not only deliver a tidal wave of torque, but also unleash the true horsepower potential of the LS1 and LS2 engines.

Right from the start, APS set out to simply annihilate the project 427 C5R Monaro and with over 25 years of turbocharging and intercooling experience, APS has produced what is arguably the ultimate intercooled twin turbo system for the GTO.

A straight forward bolt on totally engineered system that utilizes the latest in water cooled turbocharger technology and with the industry's largest bar and plate intercooler, APS delivers a system that results in outrageous power and torque right across the entire RPM range.

With insane horsepower and monster torque, the APS Intercooled Twin Turbo High Output System performs like a strong 9L Big Block and raises the GTO or Holden performance enthusiast exclusively into the supercar club!

With APS production components of equal to or higher than factory quality and specification, the look and feel of the APS Intercooled Twin Turbo system is one that screams the professionalism that APS High Output Systems are renowned for.

Lift the hood and the engine bay looks neat and purposeful - a quantum leap over any turbocharger or supercharger systems available today - a signature of APS workmanship.

But great looks don't just stop there. At the business end under the engine bay is where all the action is.

High engine bay temperatures have always been the Achilles heel of forced induction engine performance. With each turbocharger tucked up under the chassis, heat is channelled away from the engine compartment for high engine durability and consistently high engine performance. With the APS stealth Twin Turbo configuration, under bonnet air temperatures are a fraction of traditional turbocharger designs. Let's face it, nobody likes to wait for extended cool down periods, when you can simply turn around and line up for another screaming pass down the quarter mile track.

High engine performance also demands a huge mass flow rate of cool air. With twin cold air intakes, one for each turbocharger, the APS Intercooled Twin Turbo system delivers the goods. With a total cold air capacity that far exceeds the demands of the base APS Twin Turbo system, there's plenty of air flow in reserve for those who wish to build larger capacity engines (400 ci plus engines).

If the turbocharger can be described as the heart of the system, then the intercooler must surely be the "lungs"!! APS has designed and manufactured a custom configured, vertical flow high efficiency intercooler utilizing custom designed light weight cast aluminium end tanks. Extremely high flow rates and massive charge air temperature reduction - a level of performance that other manufacturers can only aspire to achieve.

With a huge 21" x 10" x 6" drag race specification bar and plate core, at 900 hp flywheel, the pressure drop is less than 1 psi. At the same turbocharger flow conditions, the intercooler outlet temperature is less than 15°F higher than ambient, at any vehicle speed over 60 mph. Truly outstanding results at such a huge horsepower level. So just like the APS turbochargers and twin cold air intakes, the APS intercooler system has massive additional headroom available for even higher power levels.

The true dual entry design of the APS intercooler system allows for the ultimate in true equal length balanced ducting from each turbocharger to the intercooler. This ensures the optimum utilisation of the intercooler core by spreading the charge air from each turbocharger evenly across the entire intercooler core - This is efficiency at its best!

The end result? Insane horsepower and monster torque for your LS1 or LS2 powered GTO. The APS Intercooled Twin Turbo High Output System performs like a strong 9L Big Block and raises the LS1 performance enthusiast exclusively into the supercar club! Are you ready for the ride of your life?

Dynamometer Charts

Before and after power and torque at the wheels.

  • Stock LS1 engine
  • Manual trans
  • 93 (R+M)/2 octane fuel (US East Coast fuel blend)
  • 60 lb Siemens injectors/GSS342 Walbro Pump (not included)
  • Dual 3" exhaust system (not included)

Power output measured at the wheels will vary according to trans type (auto trans delivers lower numbers at the same boost pressure), fuel quality, elevation, ambient conditions, wheel/tyre choice, dynamometer type etc.

Automatic Transmission: In order to accomodate the stock auto trans, boost pressure will require attention to limit the amount of power and torque through the trans. Please discuss this with your APS dealer prior to commencing installation.

APS Intercooled Twin Turbo System Tuner System
Turbochargers Intercooler
Twin, extreme efficiency, super compact, liquid cooled turbochargers with a custom APS aerodynamic configuration

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Massive APS DR Series Bar & Plate Front Mount Intercooler with unique cast alloy end tanks

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Ducting Exhaust Manifolds
Polished Stainless Steel and TIG welded intake and turbocharger discharge ducting.

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High Energy cast super tough high Silicon/Moly iron and precision machined exhaust manifolds and turbine outlet housings.

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Air Intakes APS Blow Off Valve
Twin High Flow Cold Air Intake System

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APS High Volume Twin Vent Blow Off Valve

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APS Twin Intercooled Twin Turbo System

Optional Products

Fuel System

Optional 540WHP bolt on fuel system.

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Optional Twin Pump Fuel Supply system. The perfect base to build high power.
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Optional Twin Fuel Rail Fuel Supply System. Combine with APSGTO-FSS/06 for 1000WHP fuel system.
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For vehicles that are required to run catalytic converters, high flow cats can be installed as shown above. Note: cats not supplied.


The comprehensive APS Intercooled Twin Turbo System for the Pontiac GTO
includes every nut, bolt and bracket required for speedy installation.




Twin turbos take the VZ Monaro from mild to wild

Drag Race Action - APS Intercooled Twin Turbo
Click here for video action of the APS Intercooled Twin Turbo Tonner's 9.81 second quarter mile pass.