As explained in our product description for the GGR Cold Air Induction System for the Focus ST, we were sure that the standard air box would restrict the flow of air into the engine, and therefore limit the power.
Road testing the car before & after fitting the system, we could feel the improvements in acceleration, and greatly improved throttle response. The power available from the engine felt stronger and the power band appeared far wider than with the original air filter fitted.

To prove the actual power gains we took a standard Focus ST to Superchips and carried out power runs on their rolling road. Firstly with the original airbox, then we fitted our system and repeated the tests.

As you can see from the graphs, the results confirmed our feelings on the road, showing that the maximum power had risen by over 17 BHP (standard 224.9 – modified 242.3), with a maximum power improvement of 20 BHP just over 6100 RPM. It can also be clearly seen how the restrictive standard air filter causes the power to drop off noticeably just over 5000 RPM, whereas the freely breathing GGR system allows the power to continue climbing all the way to 6500 RPM. Torque improvements were shown as soon as the engine started to produce any power, with a maximum increase of 17 lb/ft at 5972 RPM.

Please also note that there were no other modifications carried out other than changing the air filter. Maximum boost pressure was controlled by the management system to standard settings. The power improvements are achieved by the increased volume of air entering the engine, and increased turbocharger efficiency. The turbocharger no longer has to work so hard to achieve the target boost pressures set within the management system. This has the additional benefit of enabling the target boost pressure to now be achieved at the higher RPM, instead of dropping down around 5000 RPM.

Click here to view the C.I.A.S Graphs...

Will removing the ECU from the standard Airbox, cause it to overheat?

The GGR Cold Air Induction System is part of the GGR ST300 2007 PDF....
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GGR Focus ST Collection 2007 PDF....