Someone school me on tall ball joints

[ElkySS89]

I understand taller ball joints correct suspension geometry but there's so many options, I need help understanding it. I see 1/2 in taller uppers and lowers. I've also seen 1in taller uppers and lowers. I'm trying to figure out what's the best combination for me.

I'm running an aluminum block LS1 on completely stock suspension and the nose sits about 3/4 in higher than the rear. I plan on running UMI 1in lowering springs but obviously, I need the front to go down further. This will be an autocross focused car.

Should I run 2 in drop in the front with sTock lowers and 1/2 in uppers?

1in drop with 1/2 lower and uppers?

I'm open to suggestions.

 

[Streetbu]

Tall lowers are for mainly lowering the front of the vehicle. Tall uppers change your bump steer for the better. 1/2" is good, 1" is better.

 

[scoti]

Tall lowers are for mainly lowering the front of the vehicle. Tall uppers change your bump steer for the better. 1/2" is good, 1" is better.

Tall 'uppers' changing Bump Steer? I don't see how.

Altering/correcting Bump Steer requires moving the placement of the outer TRE vs the inner (pivot-wise). Making that change w/a stock G/metric spindle can be done by varying the height of the lower BJ. Going to the 'tall' lower BJ also adds to the overall spindle height (impacting the Camber curve) and creating some drop.

The taller upper BJ would impact the Camber curve values by making the final spindle height taller.

My research suggests the .500" taller lower BJ & .500" or 1.00" taller upper BJ are the most commonly recommended (reliability wise). If you get greedy on the lower BJ height that retains OE G-body size specs, it can be a liability.

 

[Streetbu]

Tall 'uppers' changing Bump Steer? I don't see how.

Altering/correcting Bump Steer requires moving the placement of the outer TRE vs the inner (pivot-wise). Making that change w/a stock G/metric spindle can be done by varying the height of the lower BJ. Going to the 'tall' lower BJ also adds to the overall spindle height (impacting the Camber curve) and creating some drop.

The taller upper BJ would impact the Camber curve values by making the final spindle height taller.

My research suggests the .500" taller lower BJ & .500" or 1.00" taller upper BJ are the most commonly recommended (reliability wise). If you get greedy on the lower BJ height that retains OE G-body size specs, it can be a liability.

You're correct, I misspoke. The uppers are for the camber curve. Guess my coffee hadn't kicked but I know you're always there to correct me!

 

[scoti]

You're correct, I misspoke. The uppers are for the camber curve. Guess my coffee hadn't kicked but I know you're always there to correct me!

My assumption was exactly that (you knew but mis-typed). Your car is definitely a good overall package/set-up w/everything complimenting each other.

I put the explanation in so ElkySS89 & others would better understand the impact of the changes.

 

[64nailhead]

Tall uppers are to correct bump steer issues. Car will need to be re-aligned after replacement. Taller uppers are for circle track cars with changed suspension height or drag cars that pull the front tire off the ground.

Trust me - this a drag race safety issue that taller uppers helps correct.

 

[scoti]

True.... They have impact on different disciplines. Seeing the video, I understand more where they help as far as tuning things.

Taller uppers can help w/adjusting things closer to optimum when they're not consistent. The idea is to have the a-arms (upper & lower) as close as possible to the same angle so there's minimal changes through suspension movement arc. I was referring a street-car/driver application when I mentioned the taller upper not impacting the steering (steering pivots @ the TRE's to spindle).