We specialize in billet CNC parts, and Onishi devised a process to modify nearly any turbo compressor housing to sound like the iconic T51R. Each compressor cover is carefully secured on a custom jig before being precisely machined in the CNC cabinet. Meanwhile, a custom insert is milled to exact specs from a six-pound billet of aluminum.

Once the housing has been hogged out and the insert milled, the two are assembled and the cover is ready for shipping back to its owner. Alternatively, We also offer brand new turbos from all the well-known manufacturers with the T51R modification already performed. The service is available for most small, mid and large-frame turbos, though larger compressor housings may cost slightly more. Some small-frame turbos may not have enough removable material for the mod.

One of the most common questions we get about this Modification, is Why do it? While independent, third-party shops have shown increased numbers on the dyno after the modification, we would like you to know that this upgrade is first and foremost for greater driving pleasure, quite simply. There may be some physics-based explanation of improved laminar flow etc, but that is squarely above our pay grade. This is all about style, and giving your turbocharger make your car really whistle! Take a listen below