View Full Version : Circle Track UCA's on an A-Body
matthimself456
01-05-2007, 02:04 PM
Trying to get the LeMans project rolling again. The plan is to use B-body tall spindles with C5 brakes. I have heard all the disadvantages of the tall spindle conversion but the fact is I can't afford anything better and I already have all the parts. So the question is why can't I run circle track tubular upper control arms instead of dropping a bunch of cash on Hotchkis or GW parts? Upper arms with the proper length and 6.5" bolt spacing are getting the job done in my head but is there a huge problem I am missing. Stock A-body arms have the upper ball joints offset toward the front so the symmetrical circle track arms will add some caster but I think I can live with that. Also: Anyone have a set of GW or Hotchkis arms handy to measure the length from the centerline of the shaft to the center of the upper ball joint?
matthimself456
01-07-2007, 09:02 PM
Nobody has tried this out? Kind of the same construction as the SC&C uppers minus the adjustability. I even found some with the offset to give close to stock caster. Maybe Ill just order a set and try them out. Can't go too wrong for $100...
sinned
01-08-2007, 08:05 PM
I ran them a year or so, ball joint selection is limited and will require reaming the spindle to fit properly.
protour_chevelle
01-08-2007, 08:16 PM
I'm running them now.
-Matt
Marcus SC&C
01-09-2007, 07:39 AM
You can run them but... Exactly what length and offset you you need for your car,at your ride height,with the alignment settings you want to run? Do the arms take std. mid sized pattern ball joints or the common circle track lg. pattern (truck) ball joint pattern? On 99% of these the steel "bushings" are the arm,the tubes are simply welded to them. Circle track guys bang their cars up so often they keep extra arms on hand so they seldom have a set on there for more than one season. They`re disposable.
As for the B spindles,we have customers calling every single day that regret going that way. Now they`re having to buy parts twice. Low buck C5 brake swaps are easier and better when installed on the original spindles (they`re modular spindles with proper brake mounting points and real nodular iron brake hubs) and you won`t end up with steering arms that are much too low and much too long. Doubling your factory bumpsteer,slowing your steering ratio,messing up the ackerman and making your turning radius larger. It`s not worth doing that for free. Yes I know there are folks running B spindles who are happy with them but then there are even more folks running dead stock A bodys that think they drive great too. IMO if you`re bucks down put the C5 brakes on the stock spindles,use the arms you have dial in as much - camber and + caster as you can (it won`t be much but it`ll be better than stock) and save your pennies until you can afford a much better setup. Mark SC&C
matthimself456
01-09-2007, 02:21 PM
I just recently heard about all these issues with the B-spindle setup. When I bought all the parts (a couple years ago) it was the hot thing to do. Original spindles are long gone so either way I would have to buy parts twice. I think I will use what I have (B-stuff) for now and if it really bothers me that much when the car is up and driving I will see about dropping some cash on better stuff. I am pretty sure the arms I am considering use the truck ball-joints. Do these require the spindle to be reamed at the top? Where did you get yours, Matt? What are the specs on them? Thanks a mil.
protour_chevelle
01-09-2007, 03:00 PM
I just recently heard about all these issues with the B-spindle setup. When I bought all the parts (a couple years ago) it was the hot thing to do. Original spindles are long gone so either way I would have to buy parts twice. I think I will use what I have (B-stuff) for now and if it really bothers me that much when the car is up and driving I will see about dropping some cash on better stuff. I am pretty sure the arms I am considering use the truck ball-joints. Do these require the spindle to be reamed at the top? Where did you get yours, Matt? What are the specs on them? Thanks a mil.
I'm running coleman spindles that have the proper taper already so I can't help you there. You can buy reemers from speedway motors or get a local machine shop to do it.
-Matt
Marcus SC&C
01-11-2007, 08:34 AM
You`ll need to ream them not because the tapers are different pitch but because they`re different sizes. Reamers run about $80-$90 so if you can find someone that already have them you`re better off. They`re automotive tapers so most industrial machine shops don`t have them. Also the truck ball joints are taller and the tapers are larger in dia. than B ball joints which alters the geometry. On the already tall B spindles that`s a bad thing,the RC ends up way too high and the front view swing arm gets really short making suspension jacking a potential problem. You`re still going to have to change the lower ball joints (which have to be machined) and the tie rod ends (wrong taper). I see where you`re coming from but it`s still a bummer to do all that and then maybe have to undo it all later... Mark SC&C
matthimself456
01-11-2007, 10:23 AM
Hmm thanks for all your help, Marcus. Looks like this might have to be rethought a little. I already have the turned down lower BJ's and proper tie rod ends. I suppose the common circle track screw-in (Chrysler) and mono-balls have the same issues with the larger taper and relocated pivots. Anybody know for sure?
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