Adjusting rear control arms?

[gnvair]

Most G bodies have the rear offset to one side. This becomes evident when you run wide tires. This will be visibly evident as the tire on one side will be closer to it's respective wheel opening. Adjusting the uppers to pull it over can help a lot on some cars, especially when rolling or cutting fender lips is not an option.

 

[michmalibuman]

Thanks for the info.

 

[pontiacgp]

setting the wheels even in the opening looks nice but if you are planning to partake in the parking lot autocross races shortening the wheel base will improve cornering.......

 

[pontiacgp]

Most G bodies have the rear offset to one side. This becomes evident when you run wide tires. This will be visibly evident as the tire on one side will be closer to it's respective wheel opening. Adjusting the uppers to pull it over can help a lot on some cars, especially when rolling or cutting fender lips is not an option.

I spent the time the line would take to build a G body to make sure the body was straight and even when I put it back on the frame

 

[gnvair]

I spent the time the line would take to build a G body to make sure the body was straight and even when I put it back on the frame

I had the body off of my GN and there is not much wiggle room to shift the body from one side or the other.
Think of this; the bottom of the cushions fit tightly into the frame holes. The top sides are flat. The only room for movement is in the center hole of the cushions; which is not much.

 

[pontiacgp]

I had the body off of my GN and there is not much wiggle room to shift the body from one side or the other.
Think of this; the bottom of the cushions fit tightly into the frame holes. The top sides are flat. The only room for movement is in the center hole of the cushions; which is not much.

not much is more than I wanted

 

[lilbowtie]

Ok dude. We will take you seriously when you build as many successful 7 second race cars as he has. http://www.teamzmotorsports.net/Default.asp

Easy gnvair it's just a fourm and people have opinions, right - wrong - or indifferent. You can take a horse to water but you can't make it drink.

 

[gnvair]

Easy gnvair it's just a fourm and people have opinions, right - wrong - or indifferent. You can take a horse to water but you can't make it drink.

No, I just found a certain irony in his bashing Dave Zimmerman of Team Z who has built many successful race cars that hook and go straight. Maybe when he makes a name for himself he can start telling Dave he is doing it all wrong.

 

[Rt Jam]

The ET of the car you build has is not a gauge for your knowledge. Also circle track cars and full tube drag cars are not stock chassis G bodies.
The opinion comes from people who have a car that is 30 to 50 years old. It drove fine and made it through a couple 4 wheel alignments. Everything is good, then one day they slap a wide rear tire and rim on and bang, they want to shift their rear housing sideways in the car. 90% of the time, this is the body mounts, the bodies fault or poorly hung quarter panels. Now you are going to run a short and a long upper arm, the lower arms will shift slightly over and the rear will Not be centered because the body is being used as a centering gauge. This is incorrect.

Team Z talks about a centerline. If the rear is out, personally I would want to find out WHY it's out. If it is the upper mounting points then That is the problem. Now it's your choice to fix the mount or run unequal length uppers. I have plumbed so many cars and will tell you OEM mounting points are almost never out. So with equal length arms the rear housing will be centered to withing a reasonable tolerance of 1/8".

So this is all words and assumptions. Let's make this into numbers. If a professional chassis was built or a new 2021 Ram right off the assembly line was built. If the rear needed to be shifted over 1/8" according to the alignment machine. We are all going to adjust to get it right in the middle of the spec, even me. Same as a panhard set up which has no heavy angled uppers to center a rear, adjust and move on. On a 4 link car, any more than 1/4" I would seriously look into WHY and correct the problem, like a bent chassis, incorrectly placed upper mounting points, axle flange to rear housing flange difference instead of running 2 different length uppers.

The lowers are pushing straight on a launch, so 2 different length lowers to correct for thrust would probably have little effect on a drag car. They will still both push the chassis forward.
The uppers are Not straight. They are on a heavy almost 45 degree angle. They pull hard on a launch and on a 7 second ride, having those at an equal length is something I'd aim for.

 

[gnvair]

The ET of the car you build has is not a gauge for your knowledge. Also circle track cars and full tube drag cars are not stock chassis G bodies.
The opinion comes from people who have a car that is 30 to 50 years old. It drove fine and made it through a couple 4 wheel alignments. Everything is good, then one day they slap a wide rear tire and rim on and bang, they want to shift their rear housing sideways in the car. 90% of the time, this is the body mounts, the bodies fault or poorly hung quarter panels. Now you are going to run a short and a long upper arm, the lower arms will shift slightly over and the rear will Not be centered because the body is being used as a centering gauge. This is incorrect.

Team Z talks about a centerline. If the rear is out, personally I would want to find out WHY it's out. If it is the upper mounting points then That is the problem. Now it's your choice to fix the mount or run unequal length uppers. I have plumbed so many cars and will tell you OEM mounting points are almost never out. So with equal length arms the rear housing will be centered to withing a reasonable tolerance of 1/8".

So this is all words and assumptions. Let's make this into numbers. If a professional chassis was built or a new 2021 Ram right off the assembly line was built. If the rear needed to be shifted over 1/8" according to the alignment machine. We are all going to adjust to get it right in the middle of the spec, even me. Same as a panhard set up which has no heavy angled uppers to center a rear, adjust and move on. On a 4 link car, any more than 1/4" I would seriously look into WHY and correct the problem, like a bent chassis, incorrectly placed upper mounting points, axle flange to rear housing flange difference instead of running 2 different length uppers.

The lowers are pushing straight on a launch, so 2 different length lowers to correct for thrust would probably have little effect on a drag car. They will still both push the chassis forward.
The uppers are Not straight. They are on a heavy almost 45 degree angle. They pull hard on a launch and on a 7 second ride, having those at an equal length is something I'd aim for.

You obviously have not worked on a lot of A/G body 4 link cars. Most that I have worked on have the rear offset. I have seen the same with Ford's Fox body platform as well. On the full frame A/G body you will not be able to move the body on the frame enough to center it without elongating the body cushion holes in the frame.
Secondly, just because the rear end is shifted to one side does not mean the car won't track straight or be out of alignment. The tracking is made with the lowers and the pinion angle and rear end location is made with the uppers. There is no issue with unequal length uppers as they do not have an affect on tracking.
Btw RT, build 7 second power and try to get it down the track without knowing anything. I'll take your advice when you do the same as Dave.