Based on your pics I'm willing to bet that OP's 1/4 coil chop is spot on for a starting point.
Cutting Moog 5660 springs
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Based on your pics I'm willing to bet that OP's 1/4 coil chop is spot on for a starting point.
Uncut 5660's with 1/2" longer lower ball joints. Heavy Iron LS with a blower and AC and the 2+2 nose is big and heavy.
For an uncut spring this is as low as you are probably going to get, unless you have a iron BBC.
For an uncut spring this is as low as you are probably going to get, unless you have a iron BBC.
Serious question. Longer balljoints ? My wagon was dropped 2" by the previous owner. When I redid the front suspension I used a stock front end kit from PST. The only issue I see is the sway bar links have to be shortened. Should I have used different ball joints ?????
My guess is the balljoints space the arm and pivot point downward to correct geometry.
So the reason 0.5" taller lower ball joints are popular is that it makes the spindle taller. That taller spindle makes more modern style camber curve through the suspension stroke.
If you have ever lifted the front of a G body off the ground you notice how the top of the tire pulls in the bottom pushes out. The problem with that is if you want the car to corner well, when you turn the car leans slightly and transfers weight to the outside of the turn and causes the suspension to squat. When the suspension squats the top of the tire pushes out which is the worst case scenario and makes the contact patch smaller. It's like if you are riding a bike, instead of leaning left to turn left, the G body leans the tire right to turn left. Essentially the stock G body front suspension camber curve is set up backwards. It has 'good' (negative) camber at full droop and 'bad' (positive) camber full compression, and the car lives at full compression WAY more often that full droop.
The issue is that because the G body front suspension was design for comfort, GM put something called 'anti dive' into the front suspension which means if you hit the brakes hard the front of the car doesn't dive really hard. From my understanding the geometry as-is prevents antidive but it is a tradeoff to camber gain in turns or in bumps.
Taller lower (or upper) balljoints make the upper control arm go from tilting down (say 5 degrees) to sitting more vertical (0 degrees) at ride height so as you hit a bump they go 'up' (say -5 degrees) and the arm essentially gets shorter which pulls the top of the tire in.
Basically tall lower ball joints are a $25/side cost increase that greatly can improve the camber curve on the car.
Crap. So do I need to change them ? And is it only the lower ? Or both ? And what part numbers should I look for ?
I don't know that antidive geometry has any bearing on camber curves. It's a fancy way of saying the lower control arms are canted forward. This reduces dive without increasing spring rate. I could see it reducing caster with compression as the lower ball joint would sweep forward. Not sure if they matched the upper or not. Even if the did, the short and long arms would sweep differently.
You don't NEED to. You can get tall uppers and lowers but tall lowers are usually enough and what most do.
If you have new lower ball joints and aren't aggressively turning corners you probably won't notice and i'd leave what you got. For a drag car that is picking the front tires off the ground or if you are often turning corners I recommend it. For a cruiser stockers are fine. It's not like the stock geometry is BAD but can be improved.
Proforged is the one most go with.
Proforged Chassis Parts 101-10048 Proforged Tall Ball Joints | Summit Racing
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You probably are right. I know antidive hurts caster gain but it's probably not helped with tall lowers. I'd defer to someone that has better understanding.
It's something I read but I very likely misunderstood.
I have said it a milion times and I will say it again. There is no formula to cut springs. You must install them, as they will be run, and if they need to be cut, then 1/4 coil at a time MAX. Sometimes 1/8 coil is even better to fine tune. Because every car/engine/transmission is different. Isn't that a PITA? Sure. But you want to get it right and if you cut off too much you now have to buy new springs and start all over. My Bonnewagon sits right where I want it and handles great. This time I did not have to cut because I used "F" body 301 springs to raise my "G" body 301 just a couple of inches. Last time I had to cut 3 times a 1/4 coil at a time to get "F" body 400 springs to sit right in my '81 "G" body wagon with a 400. That 1/4 coil made a HUGE difference each time I cut so be careful.
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