4" Downpipe: GTI / GLI (Mk7/Mk7.5 · MQB) | Big-Bore 400-Cell GESI GEN2

The 4" Downpipe is our maximum-flow, big-bore downpipe for the Mk7/Mk7.5 GTI and Jetta GLI — built for higher-output and hybrid-turbo setups that want the most out of the exhaust. Fully TIG-welded, back-purged 304 stainless with a high-flow 400-cell GESI GEN2 catalyst in a 4.5" housing. Originally a Baun Performance design (GTI Jake) — this is the same big-bore downpipe formerly built by Baun Performance, now hand-built by Brockett Built. ▶ Watch the Original Build by GTI Jake (Baun Performance) Pairing with a cat-back? Add a midpipe. Do you have a specific cat-back you're pairing with? Our resonated midpipe is built to fit both this downpipe and your cat-back — select the 3.5″ diameter to match this 4″ downpipe, choose your cat-back, and we size it to bolt right in. Add the matching resonated midpipe → Fitment VW Mk7 & Mk7.5 GTI — 2015–2021 (front-wheel drive) VW Jetta GLI (A7) — 2019–2025 (front-wheel drive) Engine: EA888 Gen 3 2.0T · best suited to stage 2+ / hybrid-turbo builds AWD cars (Golf R / Audi S3 / A3 / Alltrack) use our dedicated AWD 4" downpipe — see that listing. Specifications Diameter: 4" upper section into a 4.5" catalyst housing Catalytic converter: 400-cell GESI GEN2 high-flow Material: 304 stainless steel Construction: TIG-welded, Argon back-purged, hand-built to order Flow: Independently bench-tested at approximately 396 CFM (downpipe alone) — roughly 143% more airflow than the stock downpipe Built to order. Contact us to confirm the right configuration for your build. Allow for fabrication lead time. Part of the GTI Jake / Baun Performance lineup, now designed and built by Brockett Built.