Also, the collectors that came with the headers has the flange welded in place, so it's a trick to get it all aligned because once it goes together it will be a bigger trick to get the collector to turn in the head pipe if the flanges aren't lined up. I will remember to see if I have separate parts laying around that I can use.
TTi welds the flanges welded solid to both the header and the "reducer" and I wasn't crazy about it. I'd bought a set of ball-flange reducers for them, only to find those won't work on welded header flanges, at least not the TTi because the weld is on the inside. The surface of the weld isn't smooth enough (and the ball flanges I got were poorly made). Back to the
drau-ring board, just as I was all set up and into the job.
There's no reason you can't make your "final" headpipe adapters
now. Both now and later you just need to get past the T-bar/transmission crossmember, be it for break-in extension pipes or the full exhaust. Why do it twice, and incur both cost and effort
twice? It's wasted money if nothing else. What I ended up doing was bolting the reducers snugly to the headers, then making my X-pipe in situ. Not having an X-pipe will make it a lot easier--I had six slip joints to align to get my outlets where I wanted them. This is one of those places where I much prefer welding over clamps, X-pipe or otherwise. A real-world situation where one would want to remove only the first 6-24" of an exhaust system eludes me, and if it did get taken apart the realignment process would
suck.
What I suggest is start like you're doing the final exhaust system. Bolt the collectors to the headers, then have a look at where you are and where you need to be. Get yourself an 18-24" extension pipe just for mock-up purposes, and see what you, the local parts store, or Walker (or any number of other vendors) have for angled bends. Whether the bends you use are mandrel or crush, that's your call (I'd suggest mandrel--read on), but make sure they're I.D/O.D., meaning they'll slip-fit into each other. Depending on where your header collectors are and how they're pointed, you'll probably need two 45s per side to get past the T-bar crossmember and then point straight back. You may need a short extension pipe after the collector on one or both sides to position the angle pipes correctly in relation to the crossmember--straight through the middle of the clearance dimples. If you look at my X-pipe, the difference in length in the 45s coming out of the collectors is evident:
You'll also notice that I slightly "over-bumped" (expanded) the pipes a bit. That gave me some extra adjustment. It made no difference in sealing since I was welding it anyhow. As goofy as it looks from this angle, that X-pipe is dead-nuts centered in the car (not to the engine). The TTi headers essentially point right through the center of the clearance humps which the Rubber Dougies might not, but you get the idea.
The reason I suggest mandrel bends in this area has nothing to do with performance. If you look again at the picture, you can see I cut the angle pipes coming out of the X on a bend (the four 45° pipes were identical). It was necessary to get the outlets where I wanted them. Good luck pulling off a nice fit, or any kind of sealing, with a crush-bent pipe in that situation. No, the rental pipe expander will
not save you.
OK, so now you're past the crossmember and the pipes would point approximately straight back, but they're all
flopsy and sensitivity because you expanded them a bit for wiggle room. If you hyper-expanded them, no problem--cut a couple of slots 180° from each other, pull it together with a U-bolt clamp, and weld (you may have to do this twice, in 90° intervals). Take your floor jack and a short length of 2x6 to hold the pipes up where you want them and level to each other. Use your extra 18-24" extension pipe to ensure they're pointing where needed (straight back) and that you've got floorpan clearance. Make any adjustments and tack-weld them in a few spots. Remove them from the car, weld them fully, then reinstall with gaskets--soft aluminum is
highly recommended at the collectors. There's no reason to remove them again. You can rig whatever sort of diabolical flex-pipe horsef__kery temporarily for cam break-in, and when the time comes for final exhaust you've already got the "tricky" part out of the way.
Or, you could just order Summit Racing's house-brand A-body exhaust system. That's what comprises almost everything on my car rear of the X-pipe. It fit well, has plenty of adjustment, and is fully mandrel-bent. The mufflers sound good without being obnoxious, but you may be able to get it without 'em and use those of your choosing. I modded the hell out of mine for resonators and Flowmaster 3"-2.5" smooth tapers but that was after I'd fitted most of it. After seeing Rusty's TTi system I'd never order that--and I have a pipe bender at my disposal. I couldn't believe the crappy fit and lack of ground clearance. For that kind of dinero, I'd expect much better. The Pypes systems I saw appear to be no better.
