New C4 Exhaust System - More Bark With Your Bite, Part 1

The flange on the Random Technologies cat converter has extra bolt holes to allow it to fit multiple applications. It also includes ports on both sides for connection of the A.I.R. tube on different applications. this is no "will-fit" universal part-it's designed for alternative mountings and was a simple and direct bolt-in.

Here's the Corsa cat-back system that was recommended by Mid America Motorworks. It's made to mount to the factory hangers, making installation a snap after the headers are in place.

Installing the left-side header wasn't too difficult. There was adequate room to lift it up into place from below. We tried dropping it down from above, but there was simply not enough room to snake it into place.

The new headers didn't come with gaskets, so we bought a set locally. Note that the bolt holes on the front and back of the gasket are not full circles, but rather are slotted. This allows us to install the header with the end bolts first to hold it in place, and then slide the gasket down into position before installing the remaining bolts.

Here you can see how easily the new gasket slides into place with the two end bolts holding the header in place. This is far easier than struggling with trying to start the bolts while juggling the header and the gasket at the same time.

As it turns out, all four of these brackets (two on each side) interfered with the header flange.

Fortunately, we didn't have to cut any material off these brackets. we only needed to bend each tang 90 degrees to prevent interference with the header flange.

The original alternator rear support bracket bolted to the rear bolt of the front tube on the driver-side exhaust manifold. The new header tube does not leave clearance for the stock bracket, so we decided to make a new bracket and mount it to the next bolt back.

We used the original long shouldered stud and made a "stand-off" tube to move the hex head out where we'd be able to attach a bracket without contacting the header tube.