Project V8 RX-7: Part 9 – The Exhaust
by Jeff Naeyaert
The title picture already gave it away, so I’ll save the prose, it’s time to build an exhaust! This isn’t going to be a sissy grandma exhaust either like on Project G35 whose owner couldn’t stand how loud the Berk exhaust they originally installed was… in fact, it's the same folks at Berk that are gonna kick it up a notch and help us make a super bitchin’ set of pipes that’ll make children cry and leave no question in any Rotard’s mind that our dead Wankel was replaced with a big ol' hunk of American
The only caveat is this has to be able to pass a smog referee’s inspection. To our knowledge, they only look at the stuff that effects emissions—not sound regulations. This is only based on our personal experience dealing with them the first time I went through inspection with the LS1 powerplant. Either way, we’ll know soon enough when we try to pass!
We do know for certain that we are required to use all 4 catalytic converters that came with the E-ROD kit—so no headers (yet).
|The exhaust manifolds and secondaries provided with our E-ROD kit.|
There is however NO way that the secondaries with the cats on them are going to just bolt up and fit as is on our RX-7 (unless we make it a Donk car) so that means we gotta chop ‘em. This is a gray area that we don’t have a lot of solid information on (feel free to comment if you know something we don’t) but it is our understanding that you can chop and turn things to fit but the cats and oxygen sensor locations relative distance from the manifolds must remain the same. In other words, we can’t chop the cats up and move them back 2 feet farther down the exhaust stream. Makes sense, and that’s something we can live with!
We decided in order to save money (not time) that we’d fabricate the exhaust sections from the manifold down past the cats ourselves using just the parts we chopped up. We’d then order new tubing to do the cat-back portion and let a professional handle that part (saving money because we’d inevitably ruin a lot of good new material AND time!)
|Time to hack!|
|All chopped up, we separated the cats from the flanges. Where possible we plan to just rotate and change the angle of the existing pipes so we maintain the catalytic converter and O2 sensor distances from the heads.|