Hello,
I am wondering if anyone has had similar issues (and found solutions) installing a Skunk2 Alpha header on their car. First off, mine is a 1991 LS Hatchback 5-Speed B18A1. Initially, I had a fitment issue with the oil pan; the collector would interfere with the lower portion of the stock oil pan preventing the flange from seating on the head studs. Skunk2 said that although their header was said to work with the LS, I had to either modify the oil pan (dent it) or find a pan that would accommodate their header. Well, not the best of solutions, so I bit the bullet and used a Moroso pan that was made for such issues. After installing the pan, and then the header, I noticed that although everything mounted up well (to my existing SS Tanabe Touring exhaust), the front most tube of the header was touching part of the lower metal framework of the front bumper, causing excessive noise (resonance) and vibrations. (You would need earplugs to tolerate it.) Yet it seems another issue using this header. So … does anyone here have anything to offer in the way of a practical (and safe) solution? Any suggestions would be greatly appreciated. Thank you.
Update: The piece that the header is touching (from what I can find on the internet) is called the front lower crossmember. And it doesn’t appear to need much material cut away from it — but it’s on the frame, not the edge flange. A small dent in it would do the job, but I’m afraid that might cause issues. How concerned should I be?
That’s funny, I had a similar issue getting my b20b into my 92 LS. The header wouldn’t seat on the exhaust mani because the pan was in the way. So I used a Moroso pan which solved that problem. Don’t know about the stock cross-member, I have an after-market traction bar that takes up much less room (but is a little heavier and cost $700). Koinky-dink I also have the SS Tanabe Touring exhaust. Nice unit.
I am no expert, but I would guess you can take a BFH and make a small dent in the crossmember (while it’s bolted on the frame to avoid possible warping issues) and be totally OK. Or grind off a tiny amount and spray some primer on it. We’re talking small though, just a hair deep and not very wide. I did that when my 90 front UCAs refused to fit in the wheel-well area of a 92 LS and have not seen any issues alignment or otherwise.
Besides, if it turns out denting your crossmember was bad, you can always pick another one up from a wrecking yard, it bolts on-and-off.
Re: SS
Thank you for the reply. I agree about the Tanabe exhaust, for the money and after comparing other options, it seems the best choice for durability and noise level. As for putting a small dent in the crossmember, in theory it should not be an issue — but one must either remove the unit (remember, there also is a front engine mount attached) or remove the header (at the head and exhaust system) in order to access the spot where the hammer will be applied.
Anyway, I also remembered that my engine mounts are original from 1991. They are all likely hard and/or sagging a bit. I’m going to replace them (all 4) and see how that changes things. It may very well reduce the vibrations to normal for the car, and lift the front end of the engine itself ever so little but enough to allow the header pipes to fully clear the crossmember.