I'd like to put a flex joint in, but where the header is broken at the collector is not circular, so it would be tough to find something that would fit. Also, it seems that extending the header length would require other changes to get everything fit back. I think the easiest route now would be to add the flex joint downstream of the cat, before the flange to the rest of the exhaust. Less effective there, I'm sure, but easy to do.

 

That might work. The 2 O2 sensors may be a problem, maybe not ( wite length ). I would not worry much about the shape of the collector, it can easily be made round to fit the cat ( this is a good place for a good butt weld - make sure to match the ID size of both pipes ).

 

Got the header welded up. Looks nice. FWIW, the shop said there was nothing wrong with the original weld. The failure was purely fatigue related, in their opinion. So, I guess OBX is vindicated.

 

Got the header back on yesterday. Just a couple of install hints, in case you are doing this yourself without a lift.
- Get the car up as high as you can. You really need to be able to wiggle the header around to get it past the front sway bar.
- I found it helpful to wedge the front sway bar out a bit (see pic). If you are using one hand to do this with a pry bar or something, you've got only one hand left to push the header up, and you don't have nearly the leverage as when the car is on a lift.
- When screwing the header on, Helix used a couple studs because the pipes interfered with the bolts going in straight. Actually, there is no need for studs. Simply put bolts all the way in thru the tight holes before the header is screwed on, then tighten these while the bolt head is still against the header flange (easier to do than explain ...).
- It is worth $5 to use better quality exhaust springs than the flimsy ones OBX supplies.
- The ball joint really doesn't need to be very tight at all (when cold) to keep from leaking. I imagine it tightens up anyways when the exhaust gets hot. Better keep the joint on the looser side and avoid cracking the header like I did. But this means you absolutely have to double nut.

 

Before I start hunting, any advice where to get springs like these?

 

WOW! I had no idea that header install would be such a DIY PITA.

 

I first went to P Boys and all they had was one selection of a bolt - spring combination. Not wanting the bolt, I went to a small independent auto store and they had exhaust springs. I think you will have to hunt around a bit.

 

inimmini, I just had a quick question a little off topic, sorry. Do you have a pic of you HAI with heat shield?

 

Has anyone added a flex joint to the exhaust that includes an OBX Header? The local shop that added the Cat for me can add a flex joint for about $85ish
Any thoughts?

 

I like it. $85 is not bad. IMHO a flex is much better for any street application especialy if you drive on roads in the NE.