Barracuda Challenger Forum

Author Topic: aftermarket control arms  (Read 680 times)

Offline Bearcuda

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aftermarket control arms
« on: November 05, 2015 - 10:54:02 AM »
Hey all, I just bought some SPC upper control arms for my 73 Cuda. I will have tons of camber and caster adjustment with these. I see that the factory caster spec is .75 degree but Im thinking the 3.5-4 degree range would be much better. Anyone with aftermarket adjustable arms, what caster are you running on yours for sportier handling?
1973 Cuda 440
1971 Javelin SST




Offline Mopar Mitch

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Re: aftermarket control arms
« Reply #1 on: November 05, 2015 - 02:22:08 PM »
Those SPC UCAs do appear to have the MOST adjustment available for caster and camber.  What is your intention with the car?  Street/hwy driven?  Pylon AX, road course HSAX/HPDE?

Does your car already have PS, or is it manual steering?

See how much positive caster YOUR car's setup can give you... +5~6~7?

You'll also want a touch of negative camber (-1-2)... unless you're only pylon AX.. then you could initially aim for -2-3.

The more +caster, the less need for lots of neg camber.

My own car... I run +5 caster, -2 camber (adjust toe pending the purpose... competition pylon AX... 1/4" total toe out; street/hyw & road course HSAX/HPDE.. zero. 
Autocross/road racers go in deeper... and come out harder!

See  MOPAR ACTION MAGAZINE, AUGUST 2006 ISSUE for featured article and details on my autocross T/A.

Offline Bearcuda

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Re: aftermarket control arms
« Reply #2 on: November 05, 2015 - 04:54:38 PM »
Just a little spirited street driven is all im concerned with, not that ill be able to corner as well as a small block car with my big ol 440 up front.
1973 Cuda 440
1971 Javelin SST


Offline Mopar Mitch

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Re: aftermarket control arms
« Reply #3 on: November 06, 2015 - 02:29:57 PM »
You're on target with +3-4-5 positive caster.  See what you can actually get (alignment shop).... +5 would be great (with about 0.75-1.0 negative camber, and ~1/16" toe-in).   The factory spec was pathetic, as well as intended for cars without such a thing as "adjustable UCAs" (they didn't exist back then.... also, the factories wanted drivers to slow down and not drive quickly through turns, etc.. most drivers couldn't handle such style of driving, nor was there the available higher +caster designed into those factory UCAs.

If you have power steering then go for the high-side (+5);  the extra effort will barely be noticeable... don't be afraid of ~ +5 caster.   I know someone who has about +7 caster, manual fast-ratio steering, used on a road course car (GT1 '67 BCuda)... not bad at all while driving. 
Autocross/road racers go in deeper... and come out harder!

See  MOPAR ACTION MAGAZINE, AUGUST 2006 ISSUE for featured article and details on my autocross T/A.

Offline Bearcuda

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Re: aftermarket control arms
« Reply #4 on: November 06, 2015 - 05:26:16 PM »
good info, thanks. I am actually the alignment tech at our shop so ill be the one setting it up. Just wanted some opnions on how high i should go on caster with power steering. Is your recommended toe for total toe or each side? thanks again
1973 Cuda 440
1971 Javelin SST

Offline Bearcuda

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Re: aftermarket control arms
« Reply #5 on: November 07, 2015 - 01:20:08 PM »
Well. i got them in today, but the most caster I could get out of them was right around 3 degrees without affecting the camber more positive. Thats a lot better than the factory .75 degree. Havent driven it yet though. It's still sitting on my alignment rack as I type this.
1973 Cuda 440
1971 Javelin SST

Offline Mopar Mitch

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Re: aftermarket control arms
« Reply #6 on: November 10, 2015 - 02:11:27 PM »
Only +3 caster?   That's surprising.. should be a whole lot more available... fudging the setup.

Total toe specs.
Autocross/road racers go in deeper... and come out harder!

See  MOPAR ACTION MAGAZINE, AUGUST 2006 ISSUE for featured article and details on my autocross T/A.

Offline HP2

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Re: aftermarket control arms
« Reply #7 on: November 11, 2015 - 11:02:51 AM »
That does seem really, really  low for an SPC arm. Most guys can get 3* positive with the stock arms and offset bushings.