The CZP Cast Bellmouth Downpipes were developed for high horsepower applications, where traditional split downpipes won't do the job. The open, free-flowing design is loosely inspired by popular high HP applications for the GT-R and other turbocharged Nissans.

As parts and tuning for the 300ZX have matured, more and more owners have dealt with boost creep issues as a result of the traditional "split" downpipe designs that have been commonplace for years. On split downpipes, the wastegate actuator often can't open enough for exhaust gas to escape, causing boost pressure to climb uncontrollably. This is especially common with downpipes that have dividers, and on vehicles with larger turbos and/or major breather mods. This has caused owners to modify their downpipes, and manufacturers to modify their designs, both of which are quick fixes that rarely address flow restrictions and turbulence caused by these modifications.

Our open bellmouth design addresses this by providing a large open port the exact shape of the turbine outlet that gradually transitions to a tubular 3" (2.8" ID) section as it approaches the test pipe. Unlike hand-made downpipes constructed from various segments welded together, our design is fully 3D modeled then cast with no rough, abrupt junctions. Just a perfect, smooth transition, from flange to flange.

These downpipes are best suited for larger frame turbos, and those running higher boost. Where traditional split downpipes will become restrictive around at around 400hp, these excel in higher horsepower applications. Compared to traditional split 3" downpipes, expect to see a 5-10hp increase at around 16-18psi, and more at higher boost levels.

Fit most Garrett GT series turbos with 5 Bolt turbine housings, including:

* CZP/Zero G5, G5V, G6, G6X, G7, G7P, G7X
* JWT Sport 530, Sport 550, Sport 700
* Z1 GT535R, GT600R, GT675RS, GT725R, GT800R
* HKS 2530
* Garret GT2560, GT2860, GT2871, GT3071, GT3076, GTX2860, GTX2867

For extra thermal insulation, we also offer optional professional ceramic coating in both silver and black finishes.