[VIDEO] 718 GT4 Street Headers Installation Guide
Refer to the video below for a complete video install guide of our 718 GT4 catted headers.
-Make sure to tighten header bolts to 30 Nm.
-Assemble both left and right bank assemblies loosely *then* tighten from the manifolds to the muffler.
From our blog post on the 718 GT4 Street Headers: This is a complete replacement from the cylinder head to the factory muffler and is comprised of three pieces per side: the exhaust manifold (header), the over-axle pipes (which contain the catalyst), and the muffler adapter. The reason this is only offered as a complete kit (and not individual components) is that our system was optimized for producing horsepower (using stock mounting locations limited power gains). All components are made from mandrel-bent, TIG-welded 321 stainless steel. These connect using gasketed v-bands for easy install and a complete seal.
This system was designed to bolt on to the car with no permanent modifications. We accomplished this by scanning the car and modeling our design in CAD, then building a prototype. After a couple of revisions we have production parts in process!
Of course, we build parts to perform, not just sound cool, so we verify everything on the dyno. The dyno proved compelling on our initial prototype, so of course, we went after more performance and learned about what the factory ECU will and will not allow. Ultimately, we landed on the right combination and it netted a 30 wheel horsepower gain with a chunky dose of torque through the whole powerband. Peak gains of 30whp and 28wtrq. Click here to get your own and see the dyno graphs.