Did they also send you the sway bar re-locator brackets as well? I'm really wanting to pick up this header, but the horror stories of fitment issues have been a cause for concern with me. I mean, unless Skunk2 got their crap together and fixed it haha
I bought this header the day before your post and installed it this weekend. It replaced a 7 year old OBX V2 that had cracked (for the third time) at the 4 into 2 welds. A botched repair weld sealed its fate (pun intended). See the picture below. Here are some thoughts. Your mileage may vary:
What came in the box: The header, cat-back adapter, donut gasket to go between them, CEL eliminator, slotted anti-roll bar brackets, Skunk2 sticker, and owner’s manual.
Comparison to the OBX: The Alpha is more substantial with cast pieces at the 4 into 2 join that should eliminate stress on the welds there. It is probably two pounds heavier (I didn’t get to weigh them) which should be a plus for durability but is a minus during installation. The Alpha uses larger diameter tubing from the second step all the way to the 2 into 1 merge. The tubes are straight for a longer distance as they exit the cylinder head. That makes for problems during installation.
Installation: Compared to the OBX the installation is much more difficult. To install the OBX only required undoing the anti-roll bar brackets at the sub-frame. After that it slid right up to exhaust ports and could be bolted on from the top. It was light enough to stay in position while I moved from under the car to on top to bolt it on. It had plenty of clearance around the anti-roll bar once everything was back in place.
There are already several tips for installing the Alpha in this or another thread. I used all of them and more. First, check the bold holes in the flange that bolts to the head. If the number 4 cylinder (driver’s side) hole isn’t as big as the number 1 cylinder (passenger side), then drill it out. If you don’t the bolt for the number 4 cylinder won’t line up and you might cross thread it and screw up your cylinder head. It’s really only about a 1/16th of an inch so it is hard to see but it will make a big difference. If in doubt, drill it out.
Disconnect the anti-roll bar. I unbolted the brackets from the sub-frame and one of the end links to get enough movement as I maneuvered the header to snake it up to the engine.
Unbolt the heat-shield that covers the brake lines but don’t remove it completely or you won’t get it back in once the header is in place. Just kind-of move it around as you are snaking the header in place then you can bolt it back in place. You will want to keep it as it protects the brake lines from the exhaust heat and nobody wants boiling brake fluid.
Remove the oil filter. You won’t need to if you take the heat shield out completely but you don’t want to do that. It’s the longer straight section of primary tube that makes these two steps necessary.
Get a friend or a jack to help: I was installing the header by myself and used a jack at the collector to hold the header in place while I moved topside to bolt it to the cylinder head.
Optional: I cut off the hanger piece that is supposed to match up to the hanger on the sub-frame. The stock catalytic converter had one but one-piece headers don’t really need it and it can cause problems if used. It cleared everything OK when installed but was making it difficult to maneuver the header under the car. I was installing the header with the car on ramps.
Fitment after the installation: Once reconnected the anti-roll bar cleared easily using the stock brackets and end links. There is more than a finger gap on the driver’s side and over the top. On the passenger side there is less but easily a quarter inch. [Edit: After driving it a bit, the anti-roll bar found its natural location and was rubbing on the header. I simply added the slotted brackets at the bushing and bumped the bar over a quarter inch. So far that has fixed the rubbing.]
I had to bend slightly the upper passenger side corner of the heat-shield just to give a bit more clearance. That was easy. The adapter mated up to my Comptech cat-back, no problems, doesn’t hang too low.
There is one fitment issue which is particular to my car and aftermarket motor mounts. One of the primary header tubes just barely contacts the bracket that connects the engine block to the rear motor mount. I tried clearancing the bracket with a BFH but couldn’t make a dent (another pun). I think vibrations will eventually wear a hole in the tube so I will probably use a pry bar or screw driver to put a small (1 mm) dent in the tube.
Constructive Suggestions to Skunk2: Correct your CNC software program so it drills the number 4 cylinder bolt correctly. Leave off the hanger bracket and use the money you saved to include gaskets for the cylinder head and cat-back flanges and spring bolts for the collector. My much cheaper OBX came with those and a header of this quality should come with EVERYTHING needed to install it.
Sorry for the long post. I hope it helps. :vtec:
