MoPar Brake Upgrade Options?
Thanks you all for you interest an input. I've been thinking about some responses and investigating your ideas.
Nice work.
Personally, I think the last thing an A-body needs (for looks) is more wheel offset to the outside. Especially with wider than stock tires, the fender lip comes into play very quickly. Even more so on the later 70+ A bodies.
I think I would try to 'rotate' the caliper away a bit from the spindle more so it can be positioned deeper and more beside the spindle. With an evenly deeper discrotor, the wheel itself will be positioned further back too, which would look good again.
Thanks for the compliment! I went into my model to investigate your idea further, and with this caliper it really is not possible to push the caliper itself back any further. Of course I'd like to as well, but the caliper mount face is designed the bolt from the back side, meaning that I can't move the caliper to the other side of the mounting bracket. The spindle is designed to mount to the front side, so I can't move it to the other side either. A machined piece could move the caliper bracket back in theory, but the biggest issue I run into when locating the caliper is that the top mount wants to hit the upper ball joint upright. If you rotate the caliper downward until it clears, its basically vertical - the maximum I'd mount it. BUT at that point the bottom caliper mount interferes with the ball joint mount area on the spindle. If you move it on until it clears the caliper is sitting at the bottom of the wheel - not good.
It was honestly more difficult to find a position for this caliper that I was hoping.
It's worth noting that without the spacer, the track width actually decreases .2" overall. The spacer is there to give more spoke clearance. I guess it's a trade off. You can have spoke clearance and a wider track, or you can have a narrow track and smaller spoke clearance. BUT, the 2002-2005 WRX calipers have exactly the same mounting pattern and dimensions, but they are 2 piston sliding calipers instead of the 4 pots. They would require much less spoke clearance meaning you wouldn't need a spacer quite so big. At that point, but kit would basically be the same as a Dr Diff stage 3 with cobra brakes, but with WRX calipers and 350Z rotors.
What material are you going to use for the hub? I used to make custom hubs from aluminum but I found that it was difficult to get the correct bearing crush. You need to be able to retain the wheels bearings when the hub gets hot so it takes a lot of crush. I eventually switched to steel for my custom hubs just for that reason but Cass uses aluminum and so does Baer. Rather than reinventing the wheel you might buy a set of hubs from either Cass or Baer and then work from there. Trying to fit good brakes inside of a 15 inch rim is a bit hopeless. Cheapest and most effective setup inside a 15 inch rim would be to use a 11.75 x 1.25 rotor and a set of big calipers. Maybe 6 piston Wilwood or something like that.
I'm planning to use AISI 1045 steel. Aluminum would be nice, but the ultimate tensile strength of 1045 is almost twice that of 6061 t6 from what I can find; also, the yield strength is a little higher on 1045.
Other hubs are specifically designed to work with specific caliper and rotor combos. I want to have hubs that are specifically designed for this application without compromise.
I don't think it's hopeless!
Finally, I really like your Wilwood idea in hindsight. Looking at it again and really digging into their product catalog, I see now that they have some calipers that would most likely be easier to mount that would fit on the rest of the stock A-body disk equipment. No hub or rotors required. If I hadn't already bought these calipers and rotors, I'd probably move that way instead!
So...your basically trying to reinvent the scarebird kit?
I've never heard of Scarebird, but it appears that their aim is to provide the cheapest means of getting disk brakes on a vintage car. Of course that's better than no disk brakes, but I don't think I'm after the stopping power of a 1990 Chevy Celebrity on a race car.
Anyway, thanks again for all your comments. And, AndyF, that's a FINE looking kit you built. I hope mine looks half that nice.