Piledriver wrote:..I was thinking more of a giant CV bolt multi-hole washer, over everything, probably with a 5 "tooth" VSS ring right at the CV to keep Subaru ECUs happy, and ~useable on everything else. Slightly longer CV bolts would be easy, but not needed if kept thin at center.
It would probably have to go on the axle before the boot/CV are installed, which really isn't that hard.
(Over the CV boot flange)...
That could work. I was envisioning placing the rotor inboard of the CV, but your idea sounds better. There are also go-kart rotors that are just a simple plate with a Woodruff-key hub (to mount on the rear axle)...perhaps you could whack the center out of one of those and drill it for the CV bolt pattern since you wouldn't need any offset. For $20 it might be simpler than making your own from plate steel. http://www.bmikarts.com/Brake-Rotor-wit ... p_612.html
Like the idea as a backup (or perhaps prototype) , but if I did a small run and had them water jet or laser cut it would cost little more.
I'm not sure CNC plasma would be accurate enough, but it sometimes is cheaper for small runs.
Addendum to Newtons first law:
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
Why not just use the Wilwood caliper with built-in parking brake? It's a floater, like most OEM disc calipers, but should be lighter made from aluminum? I'm guessing the integral "floater" bracket is steel though, partially defeating the unsprung weight increase. It's also sized for the thinner (0.800") vented rotors at minimum, so no solid rotors.
I've fitted 2-piston Dynalites in the rear of my buggy and added mechanical spots (but not the Wilwoods - a much nicer and $$ unit). I was trying to keep the unsprung weight as low as I could with readily available parts. Still adds up though - my upright and hub assembly with brakes ticks in at 50lbs. A lot of that is due to the chromoly hub though - that sucker is heavy!
If I trusted the CVs more I'd mount everything inboard.
Maybe with 930 CVs.
Hell you could go with 1.25" rotors/iron calipers and not care.
Unsprung weigh matters most as a % of vehicle weight....
Extremely light weight vehicle like yours built for AX I'd very seriously consider it.
I'd also consider aluminum bearing carriers/hubs and all, or perhaps some bits off the Saturn Sky.
IIRC that has an all aluminum suspension, aluminum carrier and micro stub-type setup.
A 7075T6 T1 style rear hub would also work fine, the real wide5s only have the tiny floating splined end of a Chevy axle driving a cap made from 7075T6... Some modifieds/sprint cars are laying down 300+ HP through each of them.
(They are a consumable but they tend to last awhile, the intensely bolted together T1 style stub/hub probably has 30X the contact area, and not floating either)
I still want to build a lightweight TOW'D based buggy using those wide5 hubs/stubs/wheels etc.
(enough that I have a set, smoking deal, even as art)
With the newer, much shorter stub axle "big bearing' (2 7/8") setup running a VW style stub axle to it would be ~easy.
Addendum to Newtons first law:
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
Decided to re-check my actual weights - the 50lb (actually 43.5lb) included the upright assembly shown above, plus the weight of the A-arm and suspension links, rod-ends, (outer) CV+bolts, axle, shock and spring and bolts (essentially all my unsprung weight).
The upright assembly by itself (as shown above) is 31lbs. The stub axle, chromoly hub and steel rotor (+ bearings, spacers, nut, etc - all the stuff an OEM IRS setup has to deal with) is 17.5lbs by itself! Everything else is about as lightweight as you can get it. The upright is beautifully constructed of thin chromoly sheet around a machined bearing carrier; all aluminum - brackets, calipers, rotor hub. The only place I believe I could lose some weight would be to replace the chromoly hub (A CB part that typically comes with their heavy-duty disc brake kit) with an aluminum version. It would be a nice weight savings (hub is just under 7lbs by itself), but not inexpensive - probably would have to go with a Jay-Cee version? An option should I deem it necessary once on the road. Keeping the OEM stub axle/hub/bearing IRS components definitely has some weight penalties! The Micro-stub style hub & stub might offer some weight savings, and likely a much better (and lighter) bearing set-up than the old VW based hardware. I've learned loosing weight gets exponentially more expensive!
Moving the mechanical parking brake inboard would only save me ~1.5lbs, plus adding ("sprung") weight of another rotor, mounts, etc. Seems like $$ is better spend sourcing some lightweight wheels?
Speaking of CV's - I was originally going with 930 CV's but instead decided to go with T2 - due to the Huge weight increase of the 930 units (+ bolts, ~1lb+ more each). Probably be OK to run them inboard, but then you have the axle spline differences if you run a smaller CV at the wheel.
Jeff
