ever boxed your rear trailering arms?
- Thread starter 79elcaminoo
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Hey you never know, i might come across parts that you want or need.. like yesterday, but i'll leave it at that......
I will point out that this is not a great thing to do for handling. It will make the car stiffer, but since the stock lower links are designed to twist and flex, removing their ability to do so reduces the ability to articulate the rear suspension over uneven surfaces. All you will do is bind up the suspension. The better way is a set with spherical bearings on at least one end so that the axle is free to move in opposing directions, like if only one wheel hits a bump at a time.
Also, if you do box them, be sure to box them all the way around the bushing ends. I remember seeing a G body Cutlass once that had the stock arm fail at the bushing hole and it wasn't pretty.
Also, if you do box them, be sure to box them all the way around the bushing ends. I remember seeing a G body Cutlass once that had the stock arm fail at the bushing hole and it wasn't pretty.
14 or 12 gauge will be plenty. I think the stock arms are made from 12.
I will both agree and disagree with some of 85 Cutlass Broughams statements.
I have nothing but positive results from boxing the arms and using poly.
Proper prep has alot to do with that.
Your lowers really don't move more then up and down on a pivot, they run almost parallel to the frame.
The uppers are at a harsher angle, are shorter and travel in a sharper arc, so I agree "they" will cause bind if all poly. That why I recommend one end is stock rubber up top.
In a perfect world, you would be all spherical or heim but they are not practical for a car that sees alot of road use.
My Drag car is all spherical/heimed up, my street car is a mix of poly and rubber.
Parts matched to intended use.
I will both agree and disagree with some of 85 Cutlass Broughams statements.
I have nothing but positive results from boxing the arms and using poly.
Proper prep has alot to do with that.
Your lowers really don't move more then up and down on a pivot, they run almost parallel to the frame.
The uppers are at a harsher angle, are shorter and travel in a sharper arc, so I agree "they" will cause bind if all poly. That why I recommend one end is stock rubber up top.
In a perfect world, you would be all spherical or heim but they are not practical for a car that sees alot of road use.
My Drag car is all spherical/heimed up, my street car is a mix of poly and rubber.
Parts matched to intended use.
Well, you have to think about it this way: when at rest, the U shaped mounting channels the bushings rest in are parallel and exist in the same plane of movement. When the axle goes up only on one side, the axle's lower arm mount moves into a different plane. You may not notice it, but this causes a certain amount of binding in the suspension. It is overcome to a point by bushing deflection, but on a really hard corner, the car will want to "lift it's leg" as the inner wheel loses traction like a FWD autocross car, or not move at all due to excessive restriction to movement. You probably won't notice it in normal driving, but you will when you push it. The same problem exists on a parallel leaf spring vehicle. The suspension has inadequate articulation on the down stroke, and thus you can lose traction on the inner wheel. My stock Frontier pickup does this to me on occasion when I am pushing it around corners. It is noticeable on that vehicle because it does not have a LSD. My point is, on a car used for hard cornering, suspension travel is important, both at extension and compression. You likewise never want the car to handle on the bump stops, but that is a different subject for another time.
85 Cutlass Brougham , for the sake of discussion can you answer these?
Why did GM box thier lower arms on some 60/70s Muscle cars?
Why do Hotchkis, BMR, Edelbrock Etc Etc all sell lower arms that are not only boxed but have poly bushings in them?
Why did GM box thier lower arms on some 60/70s Muscle cars?
Why do Hotchkis, BMR, Edelbrock Etc Etc all sell lower arms that are not only boxed but have poly bushings in them?
shotgun said:
Because the main concerns are cost and straight line acceleration. They can be used, but are far from ideal on a road racing setup. On a drag car, they are fine, probably the best solution short of a solid bushing. On a drag car, you just want it to launch straight and stay straight, so keeping the rear wheels pointed at the fronts is the main priority, not articulation. Remember that most 60's musclecars were in no way intended to go around a corner well! Why else would you put an iron headed big block in a car with 4 wheel drum brakes ,skinny tires and a 60/40 weight distribution? Plus, the tires back then were atrocious bias plies, usually in some gad awful 14 in size with a 70-75 series tire (LS-6 Chevelle!), or Firestone Wide Oval 60's if you paid extra. That was 40 years ago. We know a lot more now than we did then. Personally, If I had more money to play with I would get rid of the useless scrap iron rear suspension in mine and go with a modern IRS with passive 4 wheel steering geometry. However, money is an issue, so I will be going with a set of Global West's spherical bearing lowers and stock uppers. I care much more about autox times than the 1/4 mile anyhow, so it's a better fit with my needs.
Also all of the better companies that market specifically to the needs of corner burners sell the spherical bearing lowers. Most also sell the poly bushed items too as a bargain basement alternative to their better stuff to make a few bucks off of people who want them. Edelbrock is a good overall company, but having looked at their suspension products (Hotchkis) vs those of the niche companies, the quality and engineering is just not there for my needs. Engine parts, yes. Suspension parts, no.
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