TruboExo: Danger! Two manifolds!

Again, I didn’t take as many photos as I really should have because I was too busy doing work. After a long night of sanding, smoothing, reading, searching, cursing, torquing, and questioning my very gasoline covered existence I‘m left with a shit ton more work to do. At least it’s all relatively pidly work now. First, the turbo manifold is on. And torqued down. Barring me having done something catastrophically wrong it’s not coming off again for quite a while. I’m happy with this situation.

However, to paraphrase Boromir, one does not simply bolt a cast inconel manifold to their cylinder head. Well, I guess you could but I didn’t. After work yesterday I went to town on the manifold with 60, 120, and 220 grit sandpaper and block. Why? To knock down the significant tooling marks on the mating surfaces. A little tedious but worth it to know I’ll get a reasonably good seal between the hot-parts. Before...

After the 60 grit...

I didn’t take photos of the 120 or 220 passes but you get the idea, much smoother and consistent mating surfaces. Why? Because leaks are bad, m’kay. Makes me wonder if people who buy inexpensive cast iron manifolds on eBay, bolt them straight to their cars, then complain about crappy sealing are aware that sometimes you have to do a little finishing work yourself. Without diving into all the potential quality issues of a $125 dollar cast iron eBay manifold, there are reasons why they’re inexpensive. Doing only the bare minimum machining of the casting is one of those reasons. Smoothing out the mating surfaces after passing them under a used up fly-cutter isn’t on the list of value added operations applied to a cast iron manifold pimped out for just a touch over a C-note. Even this manifold, which cost a bit more than a dodgy knock-off BEGI casting, needed a little love. That’s fine, I expected that. The turbo manifold is now quite securely fastened in place with Stage 8 M10x1.25 locking fasteners. The tabs keep the studs/nuts from backing out if they happen to rattle lose. Maybe excessive but it’s peace of mind and they look bad ass. Sometimes looking bad ass is reason enough. I also replaced the rubber fuel lines and fuel pressure regulator o-ring which were 20 years old. Again, preventive peace of mind stuff for the short term. My whole fuel system will be revisited later on when install a FlexFuel sensor, adjustable FPR, and fuel rail. I also see a set of dry-break connectors in my future because because hosing myself down with gasoline sucked balls. Then it came time to wrestle the intake manifold into place. That thing is a mild pig to put on, Mazda only kind of sort of pretended to machine down the casting flash on those intakes. All in all it wasn’t too bad to put into place but you gotta work for it and it’s gonna hurt. I also completely failed to take any pictures of the before or the process but you can enjoy a photo of the result.

Before calling it a night I plugged in the fuel pump relay, turned the car on, and pressurized the fuel system to check for leaks since I’d just finished putting all of that back together. Super happy to report that there are no leaks that I can see...yet. Next, mounting the turbo and exhaust, running the turbo water and oil lines, fitting the waste gate actuator.