JMS Racing Subaru WRX STi at the Texas Mile

JMS Racing Subaru WRX STi at the Texas Mile

by Erik Jacobs

JMS Racing is no stranger to AWD performance, having been in the Mitsubishi Evo game for some time. They also have been around the block when it comes to drag and other straight-line racing, having built the first 9-second Evo in Texas.


Recently, a customer from Celaya in the state of Guanjuato, Mexico, came to JMS with the specific goal of setting a mile speed record in a Subaru. JMS didn’t hesitate to take on the challenge. While the STi may look relatively tame on the outside, the cliche holds true — looks can be deceiving.

The venerable EJ platform was updated for the mid-2000s U.S. STi release, and JMS stuck with the EJ257 that came with the chassis. They didn’t leave it stock, though. A thoroughly worked closed-deck block (JMS’ own handiwork) was stuffed with 10:1 CP pistons and topped with a JMS built and ported cylinder head complete with even more goodies.

The original top-mount intercooler and manifold were replaced with a Process West intake manifold. Normally JMS uses Cosworth intakes, but they were interested in testing out the Process West gear.

An ATI Super Damper is used to help keep things spinning smoothly. JMS says that they have had good results with the ATI dampers across all the platforms they work with.

A twin-scroll Precision 6870 turbo with a 1.15 AR has been located just behind the grill in order to give it maximum exposure to the air that inevitably comes rushing by at ludicrous speeds. Boost is kept in check by a combination of two TiAL 38mm wastegates and a TiAL 50mm blow-off valve. JMS Racing prepared one of their custom front-mount intercoolers based on a Garrett core, and fabbed up all of the piping in between.

JMS went back and forth between a dry sump and a traditional oiling setup. For the Texas Mile record, a Killer B Motorsport oilpan and pickup were used. The pan has a 30% higher capacity while the pickup is 300% thicker, reinforced, and has extra bracing. There will be no oiling issues here.

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