The rally thing to do is to mount it as far back as possible to keep the likelihood of melting down low. Like using it as the tailpipe. And if you do clog it, it's easier to repair/replace if there's only one connection to the exhaust.
Plus red/orange substrates look awesome in photos 
Man, it's a shame you need a radiator and stuff. Those headers are begging to both cross over the front to the other side.
In reply to Pete. (l33t FS) :
The bigger problem is cooking the serpentine belt...
In reply to TurnerX19 :
This is true, but philosophically, there were millions of turbo Subarus with the exhaust routed right there next to the plastic timing covers and belt, and the newer ones even put the turbo there up front.
180s, cats, and wiggles around subframe completed for both sides. This is probably all I'm making exhaustwise until the car is further into the assembly process. The hanger things go to the sides of the block to support the tubes while still letting them move with the engine.
Not the happiest with the welds but they're strong- the discounted U-J bends I got from speedway really weld kinda poorly no matter how much I clean them.
Welded and painted some harness anchors for the lap belts:
The final thing to make this a "roller" for shuffling around at cage time, was to make it steer again. I had already extended the steering support, and a Corolla intermediate steering shaft and a 3/4" heim made a nice extension for the upper section of the column, but the lower column had to extend a bit to meet it- the collapsible square section is about .76" square so some 1/8" wall 1" square tube just needed a tiny bit of grinding to fit:
Cut, drill, grind:
Plug weld and lap joints with plenty of amps:
Works nicely, seems like I got it all concentric since it feels smooth from lock to lock. This leaves me with about 3" of collapse at this section, and a few inches in the upper column as well:
Always satisfying to set it back down, that car in the background needs to take priority for Sno*Drift so this timing is good:
This angle really emphasizes how far back things have moved:
Well ok, another small project since the parts arrived. The front WRX calipers bolted right up, but the rears needed a little help and I honestly just don't like any of the little aluminum adapters on the market, so I made a different potential problem and welded a huge thick tab to the cast iron knuckles instead:
Also visible there is the significantly cut down backing plate- I may weld a duct tube to these at some point but right now they're just a spacer to keep the hub in the right spot:
Calipers bolt to one stock hole and the new tab, and the stock lower caliper bolt spot is repurposed for what will become a wheel scraper mount once I have wheels picked out (if anyone has contacts at Speedline, Enkei, Compomotive, or Evo Corse I'd love their info); the tapped holes in the top surface are for a different thing:
Originally I didn't want to use these Subaru calipers, because that little fluid crossover bump tends to wear through and cause a failure eventually- if somebody makes a steel clone of this caliper I'll buy it, but for now my thought is to protect them instead:
The fasteners are in line with the fluid passages to hopefully deflect any direct hits, and the shield will be safety wired to either the caliper itself or the pad pins. It'll probably make noise anyway and may be a terrible idea but caliper failures are really scary so I wanted to try something here.
It clears a 15x6.5 VW wheel which is hopefully worst case for caliper clearance compared to proper rally wheels.
could you separate the caliper halves and have an aluminum welding pro "build up" the bump area to be stronger/more beefy?
In reply to irish44j (Forum Supporter) :
If I did that I'd probably keep it together and have them just tack a sheet of aluminum over the whole section- the XR4Ti had a welded cast aluminum intake manifold for a while and it liked to crack.
I would taper or contour the leading edge so inbound debris gets pushed towards center, and use these as the mud scrapers. Maybe another attachment as well. The build up idea has a down side with metallurgy because it will be even softer than the original caliper, and the possibility for damaging the sealing surface.
In reply to TurnerX19 :
There will be additional scrapers perpendicular to the inside of the wheel before these, I usually angle them a bit so they eject the dirt towards the center of the car.
So, Adam isn't here yet, but he's working on some stuff for the car already- and it's a neat full circle moment. GRMer Spearfishin, who found 9HIO and Adam through my L2wd car thread, gave him a bunch of leftover aluminum filler rod when he had his E46 caged. That filler rod ended up in the skidplate for this car:
The idea with this new skidplate was to get all the fasteners up off the bottom so they don't get mashed/snapped off. The bends are all "pizza box" style cutouts since it's very difficult to bend 6061; the welded walls and pockets should also make it a great deal stronger than the simple flat skidplate on the L2wd car.
Those knuckles are most likely cast steel, not cast iron.
Easy way to tell the difference is to file it. If the shavings are bright and shiny slivers, it's steel and going to be weldable. If you get graphitey black powder, it's cast iron.
Years back I had to cut half an ear off of a knuckle due to a seized bolt situation. I welded a thick strip of steel over it, retapped it 12x1.25, and ended up reusing it for rallycross/daily driver use. It was one of the fasteners that held the strut housing to the steering arm, which is the part the ball joint attached to, so kind of a critical fastener It held up just fine.
We have a wing core with steel spars and 6X1.0 threaded inserts at the spars. Layup starts Wednesday or Thursday.
I guess this begins the phase where other people with much greater skill than I possess take stuff and run with it, because as noted Bill has the wing; and 9HIO has arrived! Cage progress thus far in pictures below, Adam says this is cage #105 and man does the practice show:
I have SO MUCH more room than in the previous car, super excited to see how he lands the rest of the cage elements:
All of the cage pictures have to be taken from a low angle because other than the backstays and the temple bars, the cage is tucked so tight to the body that it's almost invisible from a normal standing height.
The order of operations is fascinating to watch too, a remarkable amount of the welding thus far had to be done with the main portion of the cage "loose" inside the car and scooted around to reach each joint before landing it back on the baseplates and ultimately centering it using the A-pillar gussets and backstays.
Close up of the nut with holes for .135 carbon fiber pins to insure the nut anchors into strong composite, the foam cannot resist rotation.
In reply to TurnerX19 :
y'all gonna release any clues on the foil section selected? 
In reply to sleepyhead the buffalo :
E423- seemed like the right specs for the speeds we see.
¯\_(ツ)_/¯ said:In reply to sleepyhead the buffalo :
E423- seemed like the right specs for the speeds we see.
yeah, nice soft Cl-Alpha curve, and a 2D predicted Clmax of 2.0. Plus, you've got a chord that looks like it's at least 10inches(?)... if so that means you'll be up into the "nice" stable predicted performance seen at a ReynoldsNumber of 200,000 by ~25mph (based on some quick math).
nice job y'all
Adam has worked his 9HIO magic and the cage is complete:
Let's work our way from back to front on this lovely collection of triangles made of tubing.
The harness bar is also the rear tower brace, and it lands juuuuuust far enough forward to allow for dual spare tires. Putting the harness bar back here allows the seats to sit back almost in line with the main hoop without the shoulder belt angles getting messed up, and technically is one less tube since the towers would've needed a brace anyway:
The backstays land on top of the towers, there's a V up to the top of the main hoop meeting the roof bars (which have a V forward to the A-pillars), and there are braces which meet the main hoop at the same height as the door bars. This configuration means there are no tubes terminating into air- we considered another lower brace to meet the bottom of the main hoop X, but that section of the car is extremely strong and has no less than 7 separate layers of OEM steel making up the box sections where the hoop lands so an extra tube probably wouldn't do much.
The main hoop itself is tucked tight to the B-pillars, the top is up in between two factory roof stampings, the X terminates in what should be an ideal location both top and bottom, the gussets are placed such that a helmet can squeeze through for storage on transits, and the door bars meet the hoop at what should be an ideal height- I was initially worried about hitting my elbow on the upper bar, but lots of flailing around with the steering wheel indicates it shouldn't be an issue:
The roof bars are placed such that my head has plenty of room, and same for the temple bar. The windshield corner diagonal and A-pillar support/FIA bar all form a nice continuous line as they junction across and down to the front cage foot, the node at the bottom has not only that bar, the half-lateral, and the lower door bar, but the front of it also has the strut tower lower forward tie, the upper tie is level with the upper door bar, and the steering support is tied into that upper bar junction on my side as well:
The dash bar is a curved design that follows the firewall at the base of the windshield while leaving just enough room for my tunnel access panel so I can service things on the back of the engine and top of the bellhousing without dropping the drivetrain. The cross braces to the front towers go through the rain tray, and the steering support has yet another nice node to the brace on my side. I will have to scoot the wiper motor up slightly to keep the linkage and the cross brace from getting friendly, but that's a small compromise to get this awesome geometry up front:
Overall, I'm extremely pleased with this cage- every critical junction has multiple triangles meeting, we have more room with our new seating position, and it should overall be an even safer car than the already very safe L2wd car we're currently running. The super cool steering bracing he came up with is just icing on this cake of structural excellence.
In reply to ¯\_(ツ)_/¯ :
Looks like it's going to be a really stiff car. Nice work to everybody involved!
All the pieces of fabric, carbon, and steel are cut and pre fit under the vacuum bag waiting for me to have two hours with zero interruption for resin layup. Wing pic soon...
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