I had 20 whp gain with ultrex el header, but it makes the car laggier. With bigger turbo, it doesn't do that anymore for some reason. Higher efficiency rang from the turbo maybe?

using the Perth-WRX mobile app

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MY08 STI 422whp at 1.5bar on E85, built by Diversion Garage, assembled and tuned by EvoR

Update from new owner: 375whp at 1.4bar on 98, at Tokyo Motorsport