Why Use PowerCaps?

For those looking at the Sanderson Lakes-style Limefire and Jayster outside chassis headers for their street rod, here is a tech tip that might save some grief, frustration, and possible damage to the headers!

You may already know that the Sanderson lakes-style headers are available with or without connections for an under-chassis exhaust system. The ability to have a throaty open exhaust or a quiet and capped lakes-style header using an under-chassis system has been something Sanderson has offered since the original design.

We have found that on stock or mild street rod engines, there is not much of an issue if following the normal installation instructions. However, on applications making decent horsepower, it is possible to damage the header or header coating near the end of the collector where the under-chassis adapter connection is located. The cause of this problem is the turbulence created by the limited distance of dead space just after the under-chassis connection and the end cap on the header (when the header is capped and exhaust gasses are being routed through an under-chassis exhaust system). The turbulence in this area causes the EGT’s (Exhaust Gas Temperatures) to rise dramatically, and in certain applications, this could cause the temperatures to exceed the thermal capacity of the header coating—causing finish damage and discoloration. The problem only seems to occur on high-power engines and engines that are regularly operating at higher RPMs—for example, considerable highway driving on lower-geared vehicles.

The solution is relatively simple but adds cost to the header purchase. Sanderson designed a component called the “PowerCap” to solve this issue. The PowerCap slides into the collector tube and provides a smooth redirection of exhaust gas flow from the collector tube into the under-chassis exhaust tubing. The PowerCap bolts securely into your header using the end cap flange, thereby removing the turbulence area in the collector horn. Another benefit of using the PowerCaps is improved horsepower by improving airflow into the under-chassis exhaust. Although the PowerCaps are recommended for higher horsepower applications, they also benefit all applications using the under-chassis exhaust connection.

PowerCaps capture hidden horsepower on applications using under-chassis exhaust connections. Under-chassis adapters allow you to run a quieter under-chassis exhaust system, and adding the PowerCaps increases power and extends the life of your headers.