ATP Turbo GT3071R Externally Gated Turbo 2002-2007 WRX / 2004-2021 STI
Just like the GT3071R kit ATP-SUB-001 but with built in flange for a Tial 44mm wastegate on the turbine housing. High flow, less exhaust backpressure, more precise boost control, even more power! Tial 44mm wastegate and dump tube sold separately.
The Garrett GT Ball Bearing GT3071R, quite possibly the fastest spooling and most responsive 450+HP capable turbo on the planet now available in a drop-in package for the Subaru WRX/STI! The easy to implement turbo assembly that takes no more than 1-2 hours to install in place of the stock journal bearing VFXX unit is made possible by a high flowing GT inspired ATP exhaust housing and a series of custom engineered components built to suit the installation.
Each GT drop-in turbo package consists of a Garrett factory assembled and high speed balanced dual ball bearing CHRA which is then assembled into a set of CNC machine ported housings that have been optimized in every aspect for maximum flow and efficiency.
All accompanying oil and coolant supply components included in each kit have been designed to properly and seamlessly bridge the Garrett GT turbo to the EJ engine so that the fit is as OE as possible.
Just bolt the turbo on, add fueling and a good tune and prepare for a blast of acceleration. Garrett GT turbos offer more than just "peak HP" numbers. These GT turbos off more torque area under the curve and more "accessible" power than any other turbos series out there.
We do recommend that you compliment your GT bolt-on turbo with a nice high flowing bellmouth downpipe and a high flowing inlet pipe to effortless channel air in and out of the turbo. Although every bolt-on GT turbo ships with a 3" inlet, we do provide a "stepdown" sleeve just in case you're forced to use the stock 2.25" inlet hose. However, as a rule of thumb, turbos, especially higher flowing units love as much inlet flow as possible. This promotes both quicker spoolup and better ultimate HP, with less boost pressure at the manifold. The 3" downpipe and bigger inlet is critical for reaching peak efficiency on the GT turbo. Please also be aware that some downpipes such as the stock catted downpipe, has a "no-flow" door at the wastegate flapper area. This type of downpipe may not allow the wider swinging wastegate valve to open all the way, thus causing the possibility of a "boost-creep" condition or uncontrollable rise in boost.
The GT3071R is a great match on the 2.5L, especially if you're looking for boost threshold that is close to stock but want enough airflow for 450+HP. Almost all the boost is available all the time even at part to medium throttle. Boost recovery between gearshifts is awesome with full boost ready even before upshift is complete as the STI lurches forward with shear enthusiasm at the onset of each gear. The 2.0L driver should not rule out the use GT3071R if his HP target is in the same range. The modern generation wheels, coupled with an awesome wheel ratio, allows even the smaller displacement engine to provide adequate motivation to get the GT3071R going for an great powerband. The competition grade turbo still offers the best response and spool time out of any unit in this flow range.
2 uppipe gaskets will be needed if using the included spacer.
*** Optional Tial 44mm wastegate and dump tube shown are sold separately ****