Airtec Motorsport Stage 4 intercooler upgrade for the Ford Focus ST225 Mk2 2.5 Turbo, developed for heavily modified vehicles with power levels of 400+ hpThis setup is intended for owners who want to get the most out of their Focus ST during sporty street use and track use.
For the Stage 4 kit, Airtec has modified the popular Focus RS intercooler so that it fits perfectly behind the bumper of the Focus ST225. Additionally, the proven 2.5-inch big boost pipe system has been adapted for use with the Focus ST turbo, ensuring optimal utilization of the entire airflow between turbo, intercooler, and engine.
The intercooler uses a 60 mm high-flow core which is approximately twice as high as the original intercooler and nearly 100 mm longer. This results in a massive increase in capacity and an impressive 127% increase in frontal surface area compared to standard.
The combination of the smooth-flow cast end tanks and the integrated Air Ram Scoop ensures that airflow is directed through the intercooler to the maximum extent, resulting in significantly lower intake temperatures during prolonged load.
The included 2.5 inch boost pipe upgrade replaces the original 2-inch piping. Thanks to the larger diameter, airflow is less restricted, resulting in better response and more power. During dyno tests, the boost pipe upgrade alone yielded a gain of 11.8 hp and 12 Nm of torque.
Do you want to keep the original symposer? Then choose the cold side boost pipe with symposer outlet.
The intercooler is available in Pro-Series Black or Natural SilverThe boost pipes are supplied exclusively in Pro-Series Black.
Important for pre-facelift models: The pre-facelift Focus ST225 features a different radiator construction than the facelift ST225 and Focus RS models. As a result, the left (cold side) 2.5-inch silicone hose can run very close to the radiator support after installing this Stage 3 kit.
To create sufficient clearance, Airtec recommends removing the radiator bracket bolt, moving the bracket slightly to the right, and then drilling a new mounting hole before reinstalling the bolt. This is a simple adjustment that takes only a few minutes of extra work, but is necessary to create enough clearance for the larger 2.5-inch cold side hose.
Should the available space still be insufficient to your liking afterwards, Airtec advises switching to a Focus RS radiator, which offers more space around the pipework.
Advantages
• Developed for 400+ hp builds
• 60 mm high-flow core
• 127% larger frontal surface area
• Air Ram Scoop for maximum cooling
• 2.5 inch boost pipe upgrade
• 11.8 hp and 12 Nm gain through the pipes only
• Smooth-flow molded end tanks
• Lower inlet temperatures
• More power and torque
• 3 year warranty
Compatibility
Ford Focus ST225 Mk2 2.5 Turbo
Frequently Asked Questions
What is the difference between the Stage 3 and Stage 4 intercooler?
The Stage 4 is developed for higher power levels of 400+ hp and uses modified 2.5-inch boost pipes specifically tuned for the Focus ST turbo.
For what power level is this kit suitable?
This intercooler kit is designed for heavily tuned Focus ST225 models with power levels above 400 hp.
Do the 2.5-inch boost pipes actually deliver extra power?
Yes, during dyno tests, a gain of 11.8 hp and 12 Nm of torque was measured by installing only the larger boost pipes.
Does this kit fit pre-facelift models?
Yes, but Airtec recommends a small modification to the radiator support to create enough space for the larger 2.5-inch silicone tubing.
