With the prospect of many C5 performance enthusiasts building high cube/high power engines, APS has specified a pair of huge external wastegates for highly stable, high boost pressure applications on the APS Intercooled Twin Turbo System for the C5 Corvette.
A wastegate is a specialist valve that diverts exhaust gases away from the turbine when a boost pressure limit is reached. The diverted exhaust gas is dumped straight into the exhaust pipe downstream of the turbocharger.
The APS external wastegates deliver a dedicated path for the diverted exhaust gas to bypass the turbocharger's turbine, hence creating the physical basis for a highly responsive and extremely stable boost management strategy that is designed to bypass massive amounts of exhaust gas from each turbocharger.
A great degree of flexibility is also offered with this wastegate configuration. With a simple change of the wastegate spring specification, a variety of boost pressures can be set - from 5 psi all the way through to over 20 psi. In addition, a separate and optional electronic boost controller can easily be fitted to the wastegate control hoses in order to deliver real-time boost control from the cockpit.
The huge wastegates are cleverly packaged so as to take complete advantage of the tight space available under the floorpan. The wastegate configuration also delivers excellent exhaust gas flow regardless of whether the wastegates are open or shut.
Like all APS precision crafted components, the stainless steel wastegate pipework is manufactured to extremely tight tolerances in all three dimensions to ensure that installation is as straightforward as possible and that fit and finish is second to none.