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Author Topic:   Moving Upper A-arm Mounts
Dirt Forum Champ
Total posts: 569
posted September 10, 2004 09:06 AM  
If you were allowed to move your front upper a-arm mounts, where would you put them?

My thinking is to get the cross-shaft on the upper as low as possible and to make the angle of the cross-shaft match the angle of the lower a-arm. In other words, I want the the upper a-arm cross-shaft (when its bolted to the mount with no shims) to be directly in line with axis through the lower a-arm mounting holes.

Am I on the right track? If not, where should I relocate it to?

The car is 3000lb Metric with Impala spindles.


Dirt Maniac

Total posts: 148
posted September 10, 2004 12:08 PM  
There are suspension programs that you can manipulate mounting points, before you start cutting and welding.
An engineer spent a week figuring where that mount went, maybe some compromise was necessary, maybe not.
I see some of the IMCA Modifieds with the right upper mounts moved forward and rotated about 45 degrees. I never can get an answer from anybody why. I'm sure there is a good reason.

Dirt Maniac

Total posts: 149
posted September 10, 2004 02:15 PM  
we move our mounts, and when we do it we allways set the car level on jack stands, put a jack under the lower control arm till it just barely lifts the frame, then use the camber caster gauge. not exactly perfect, however, when we set it on the ground to set the true camber caster its pretty dang close, not very many shims whatsoever. we also drill another hole so the cross shaft is level, sometimes we have to wallow out the shock mount hole a little. been doing it this way for years, and know tons of other guys to do it as well. good luck

Dirt Maniac

Total posts: 137
posted September 10, 2004 04:00 PM  
IT would be best to get the upper pivot points on the exact same axis as the lowers. but it cant be done with oem uppers. you must use lefthander or other brand adjustable arms, the kind with swedge tubes and heims. they have a template and are easy to install.

with oem i tried removing the oem anti dive, and lowered them to what my program said got me to a 5 in roll center.. suffice to say i just put them back up at oem. for legality and it was rolling over way too much on the rf. 5-6 inches.

Dirt Forum Racer

Total posts: 88
posted September 11, 2004 04:56 AM  
I run a 77 Monte carlo and not sure if it works on others, but I took the front bolt of the upper right a-arm and drilled a hole as low as I could without the a-arm hitting the frame and adjusted the camber. This rolls the right tire forward which has help me to get thur the turns with ease. Was something a friend told me to try that raced in the old school, he's in his 50's and has about 6 championships racing in PA. Give it a try and see what it does for you, if you don't like it you can put it back like it was.

Drive every lap like it's the last 8-)


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