At Vette we love bolt-on performance parts. Maybe it’s the nearly instant gratification they provide or it could be that they are easy enough for a caveman, or editor, to install. In any event, they are the backbone of our hobby.
For now, our C5 is fielding its original LS1 powerplant. But, like any engine, our LS is simply a big air pump. Restrictions on either the intake or exhaust side of the equation means power is being lost, which is never an optimal situation. A high-flow cold-air intake can help move more atmosphere in, but backpressure on the exhaust side would hurt any possible gains. So, helping an engine exhale will help it in inhale, and that equates to more ponies at the rear tires.
On the exhaust side a cat-back exhaust system would free up a few horsepower, but to really make an impact, changes need to be made closer to the action — at the heads. Yep, headers make a huge difference in exhaust flow and the biggest gains come from long-tubes. Of course, if you’re rolling a street car in an emissions state then look at CARB-certified pipes. CARB stands for the California Air Resources Board and if can pass in California, it can pass anywhere.
01. The engine bay of a C5 is a very crowded place, so even getting to the stock exhaust manifolds is challenging.
02. Under our 1999 C5 FRC you can see where the exhaust pipes bolt to the cast-iron exhaust manifolds. We sprayed the fasteners down with some penetrating oil to help break through the rust. The bat-wing oil pan doesn’t make this job any easier.
03. The easiest path was just to remove the mid-pipe, with cats, from the Corvette and set it aside.
04. The passenger-side exhaust manifold came out without much hassle. We simply had to remove some lines and pull the plug wires. The driver-side required the removal of the lines, coil packs, and alternator.
05. With the stock manifolds out, it was time to get the new JBA long-tubes in place. First up was the driver-side. At first, we simply disconnected the driver-side engine mount and used a pole jack to lift the engine. This still didn’t give us enough clearance, so we removed the engine mount, oil filter, and the sender plate just above the filter. The header still didn’t fit so we also pulled the steering shaft. With all of that out of the way the header was able to slide in from the top.
06. This is our track car, so we went with long-tubes. But, if you’re dealing with a street car that needs to pass emissions, then Doug’s Headers has you covered with its CARB-certified 1 5/8-inch shorty headers (PN D3331). They look better, weigh a lot less, and give a small horsepower gain. Best of all, these are mandrel bent from 16-gauge tubing and are 50-state legal. Like the long-tubes, they come in raw and ceramic-coated finishes. Also, they are a direct bolt-in part.
07. For real power gains, though, nothing beats long-tube headers. These 1 3/4-inch ceramic-coated stainless pipes from JBA (PN 6817S for 1997-’00 Vettes) are designed specifically for the tight confines of our C5 engine bay. (Part number 6818S fits 2001-’04 Vettes.)
08. While they are not 50-state legal in terms of emissions, they still have all the proper air tubes, O2 sensor provisions, and do not require the relocation of the cats. They also have thick 3/8-inch CNC laser-cut flanges and JBA’s patented Firecone collector.
09. We were expecting them to install from the bottom, but it turned out they slid in, once all the previously mentioned parts were removed, from the top.
10. Once loosely in place we reinstalled the engine mount, oil filter, and steering shaft.
11. The passenger-side was much easier and, aside from removing the plug wires and using the pole jack to lift up the engine a bit, only required us to detach the starter. Pro tip: make sure the starter bolts are back in place before securing the header to the engine. If not, the collector tube will interfere with inserting the bolt.
12. With both headers in place we reattached all the other bits like the alternator and coil packs. Here’s the view under our C5.
13. In addition to the headers, the box also contained V-band hardware, adapter tubes, flange gaskets, and hardware.
14. First up was attaching the adapter tubes to the headers with the V-band clamps.
15. We then trimmed off the mid-pipes just forward of the cats. This metal is pretty thick, so use a good blade, and have a spare.
16. We were then able to test-fit the sections together and make any needed adjustments.
17. Once lined up, we MIG welded the seams.
18. And here’s the finished project. Total install time was a full 8 hours and while we wouldn’t call it easy, it wasn’t rocket science. Now that the headers are in they fit great with plenty of clearance around the tubes. Thanks to the band clamps, ground clearance remained the same. We didn’t have access to a dyno but we’ve found that long-tubes free up around 30 horsepower to the rear wheels. Since there’s a stroker LS3 in our C5’s future these new high-flow tubes will really pay off.
When doing installs like this, it’s a great time to inspect various components and, if needed, do a little preventive maintenance. In our case, we noticed a couple of the original plug wires were burnt, so we decided to replace them with a set of JBA low-resistance plug wires (PN W0807). Aside from looking good they feature extra-thick plug boots and are designed for extra header clearance.