Remember the Tomi / Cusco STi ? Remember how it ran crazy fast times at Buttonwillow? Remember the HKS Evo and how it holds the record at Buttonwillow? Well things are a changing. Sierra Sierra’s Time Attack Evo * recently beat the Tomi / Cusco STi’s record and is closing in on HKS’s time 1:43.523.  Eric Hsu posted up the following on his blog:

“Last week I went testing with the Sierra Sierra team to test out a bunch of new stuff on the EVO 8 at Buttonwillor Raceway. Some of these new modifications include revised front suspension geometry, stiffer spring combo, larger Garrett T04 turbo, Full-Race twin scroll exhaust manifold, larger exhaust, and a pair of larger custom Cosworth cams. Did it all work? So far so good. I think we are definitely making progress. On Hankook C91 DOT tires and the middle boost level, Dave Empringham piloted the car to a 1:44.2 on Buttonwillow’s configuration 13 clockwise. Good enough to smoke the Tomei/Cusco STi’s, but not quite HKS’ 1:43.523 yet.”

Check out the video after the jump!