upper control arm washers / degrees camber
Thread Starter
thing knower
Joined: Mar 2017
Posts: 3,404
Likes: 943
From: wpb
upper control arm washers / degrees camber
so i purchased a set of the AMT upper control arm studs and camber plates....
the way i set up my system came out to exactly ZERO degrees....
i wanted to add some negative camber, to try to get a good "street" setup...
i pulled a single washer from all 4 studs (had the 4 factory washers in their original location)...
i measured the washer and it comes out to 2.5mm...
2.5mm in inches is 0.09843 inch
that works out to 3/32nds
AMT doc says...
1/16’’ thick shim reduces camber by approximately .3 degrees
1/32’’ thick shim reduces camber by approximately .15 degrees
so 3/32nds should be .45 degrees......
so -.45 degrees on both sides should put me at total -.9 degrees total camber.....
is my math correct here?
the way i set up my system came out to exactly ZERO degrees....
i wanted to add some negative camber, to try to get a good "street" setup...
i pulled a single washer from all 4 studs (had the 4 factory washers in their original location)...
i measured the washer and it comes out to 2.5mm...
2.5mm in inches is 0.09843 inch
that works out to 3/32nds
AMT doc says...
1/16’’ thick shim reduces camber by approximately .3 degrees
1/32’’ thick shim reduces camber by approximately .15 degrees
so 3/32nds should be .45 degrees......
so -.45 degrees on both sides should put me at total -.9 degrees total camber.....
is my math correct here?
Supporting Vendor
Joined: Mar 2016
Posts: 2,738
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From: Clifton Park NY
Your math is looking good however most people don't speak of camber in terms of "total camber". That's usually a toe terminology. What are you doing with the car that you're looking for so little negative camber? Most people use the camber plates for their gross adjustment and then fine tune with the shims up top.
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Mark Petronis, 2023 C8 #266
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Mark Petronis, 2023 C8 #266
President - AMT Motorsport
Mark@AMTMotorsport.com
Facebook The 'Gram
518-877-8560
Safety Car
Joined: Jun 2017
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From: North Georgia, USA
Math is correct for near zero degrees. The angles per inch are not linear and change some, even within the range of (admittedly extreme) camber angles.
Set camber/caster first. I usually go back and forth between those a few times if I'm going for a very precise alignment. Then set toe.
As @Mark@AMT Motorsport pointed out, we generally don't speak of "total camber." However "Camber split" and especially "Caster split" is important. That's left minus right instead of adding them. You want a caster split of as close to zero as you can get for track/autocross, and and some folks dial in slight split with the lower caster on the left side (in countries that drive on the right side of the road) to give it a slight pull to the left to counteract the "crown" of the road. A car with a caster split will pull to the side with the lower caster angle.
Camber split also gives a slight side thrust, but the effect is much smaller and generally can be ignored.
Set toe after you have caster and camber set properly. Toe changes shouldn't change camber and caster, but changing either caster or camber (or both) will change toe because of where everything connects to the upright/knuckle.
Set camber/caster first. I usually go back and forth between those a few times if I'm going for a very precise alignment. Then set toe.
As @Mark@AMT Motorsport pointed out, we generally don't speak of "total camber." However "Camber split" and especially "Caster split" is important. That's left minus right instead of adding them. You want a caster split of as close to zero as you can get for track/autocross, and and some folks dial in slight split with the lower caster on the left side (in countries that drive on the right side of the road) to give it a slight pull to the left to counteract the "crown" of the road. A car with a caster split will pull to the side with the lower caster angle.
Camber split also gives a slight side thrust, but the effect is much smaller and generally can be ignored.
Set toe after you have caster and camber set properly. Toe changes shouldn't change camber and caster, but changing either caster or camber (or both) will change toe because of where everything connects to the upright/knuckle.
Thread Starter
thing knower
Joined: Mar 2017
Posts: 3,404
Likes: 943
From: wpb
Your math is looking good however most people don't speak of camber in terms of "total camber". That's usually a toe terminology. What are you doing with the car that you're looking for so little negative camber? Most people use the camber plates for their gross adjustment and then fine tune with the shims up top.
yeah, i wrote the post quickly during a break from work and now realize my thinking was backwards...
so when i install the upper studs, do i want to keep the 4 oem washers? or leave them out?
i was trying to match up against the existing OE adjustment settings as i had just had my alignment done with the stock eccentrics...
i get what you're saying about the camber, i was thinking i wanted -1 degree up front, not per side but total,...
my thinking was that since i was at 0* camber up front (measured on a rack), i could just pull shims to leave the camber plate at their current setting and achieve a "street" adjustment...
then if i knew what my "street" adjustment was, i could turn the lower plate to get more neg camber when i wanted to hit the track...
i guess that was one really long brain fart i had going on there
thanks for the help all!
i'm gonna bust out my chassis engineering book tonight before i stick any more of this foot in my mouth...
Last edited by drewz06; Sep 21, 2021 at 09:10 AM.
