The Praxis Fabrication 2nd Gen Wastegate Kit pairs a T4 one-piece stainless steel manifold with an external wastegate and hood-exit stack to help manage exhaust drive pressure in your Cummins turbo setup.

Backorder notice: The ITI manifold is currently backordered. Once your order is placed, we will email you with the estimated lead time.

What's included

• T4 one-piece stainless steel manifold
• FIS 45mm wastegate
• Hood-exit stack
• Manual controller with fittings and lines

Why run an external wastegate?

Choosing a turbine housing for a turbo such as an S400 often means balancing low-end response with top-end flow. A tighter housing, such as a 0.90 A/R, can help the turbo spool sooner, but it can also become restrictive at higher engine loads, increasing exhaust drive pressure and exhaust gas temperatures (EGTs).

A larger housing, such as a 1.10 or 1.25 A/R, offers more exhaust flow at the top end, but may come with slower spool-up and reduced low-end response.

An external wastegate helps manage that trade-off by allowing a portion of the exhaust gas to bypass the turbine housing when the gate opens. With the right setup and tuning, this can help retain the response of a tighter housing while reducing excessive drive pressure and EGTs at higher loads.