With nearly all parts having arrived, things are starting to look up, and it’s just a matter of getting things together. I took sometime today to plop the old motor back in the car, and test fit our manifold and turbo.
I stated early that I wasn’t entirely happy with our manifold, and now perhaps… I’m even less happy. The initial problem was a big mess inside the outlet. It’s a massive eyesore inside with big caps and lips and nasty welds… It looks alright on the outside, but there are obvious concerns regarding air flow as a result. The second issue is the angle at which the turbo sits on the manifold. It points down about 10 degrees. I don’t know if this is really a problem or not… so I have no reason yet to be concerned… but it’s not something I’ve ever noticed on other manifolds.
On the car, it’s clear we probably want to modify things slightly. We bought this manifold knowing it put the turbo (specifically the wastegate actuator) in very close proximity with the distributor. In fact, it’s so close that plug wires aren’t even close to fitting. The solution we had planned for this was an AE92 or AW Distributor cap that points straight up. Furthermore, these cars came with a metal heat shield fitting underneath the distributor which could be used in addition to, or in place of the OEM foam heat shield equipped on the AE86. The next, and unexpected issue is oil filter clearance. We were aware of this problem when shopping but were assured by our seller that there was adequate clearance, even with the cooler. This unfortunately is not the case, although the filter may fit, the turbo must be removed to replace it. Not acceptable.
That said, downpipe construction looks relatively easy as the turbine points nicely into the gap between the frame rail and steering column. However, I think we can make that run even simpler, and solve the other problems by spacing the turbo about 1″ further away from the head. That should give enough room to replace the oil filter without difficulty, and should also create a little more clearance with the distributor. While doing this, we can clean up the nastiness inside the outlet… it should make me quite content.
More trouble… closer looking at the FC intercooler makes me feel like it’s a very difficult fit. I’ve learned a whole bunch about intercooler design in the past few weeks and… for good or bad this has kept me from making a couple purchases. Lag is our absolute worst enemy in this project, and I’m unwilling to make big compromises. The FC has nice and efficient looking end tanks though, and is a good compact size. Notably, I’ve seen it spec’ed on various turbo AE86’s by Japanese tuners (like Ukiya Shokai), but I’ve never seen revealing pictures of mounting. Some things that we want to keep in mind when mounting are… weight: we’re already adding a turbo to the left side of the car, lets not add the extra 10 pounds on intercooler on that side too. I’d much rather see it sit on the left side, and of course, lower is better. Second… protection and durability. Maybe Ryan doesn’t crash that much, but I’ve been known to randomly jump a curb and go driving in the grass. A common fitment includes running plumbing underneath the radiator, this would certainly be most convenient, but I don’t think it’s appropriate considering I only want to do this once. But… other mounting is not very simple. In the above picture, the highlighted areas represent usable space for us to run plumbing through the rad support into the engine bay. Another option might be acquiring a smaller radiator that enables us to run plumbing through up high, in an area that is otherwise sealed by the headlight assemblies.
So… I’m still shopping around. More later…