GMG 991 Speedster WC-Sport Exhaust System

We are particular about what things are made from, which is why we build with Docol R8 tubing rather than whatever the steel yard had that week, and why our merge collectors are now 3D printed instead of fabricated the way everyone else still does it, because the printed part does the job better and the old way was leaving something on the table. None of it is done to look clever. It's done because the material that survives a season at the track is rarely the material that was easiest to order, and we'd rather go find the unorthodox thing than sell you the convenient one.

Every GMG part is produced in Southern California by our own engineers and fabricators, and the process runs the whole way through the building: the 3D scan of the car, the engineering and post-processing, the first prototype, and the beating that prototype takes at the hands of our professional drivers and the crew who support them before anyone is allowed to call it a product. Every name in that chain is one we know. The partners whose products we list are held to the same expectation, because putting our name next to something means we're accountable for it, and we'd rather do without a listing than explain one away.

Our home track is a short walk from the shop door, which means every harness bar, exhaust and performance part we sell has been run in anger under real conditions on our own cars before it goes on yours, and the ones that didn't hold up never made it to this page. That is the entire value system, and it comes from a lot of hours in competitive racing, where a failed part is a wrecked car rather than a bad review. We don't sell vanity upgrades. If a part is listed here it changes something you can measure or feel, or it makes the car safer, and if it does neither we have no interest in taking your money for it.