Bergman Auto Craft

[BergmanAutoCraft]

Here is a shot of good suspension geometry. Using our 2.0 SPC arms with taller ball joints and F spindles (taller) geometry changes for the better. For those concerned about F spindles, the SPC arms feature higher articulation ball joints than the typical K772. Combine with 7.5 degrees caster and only .5 deg neg camber, roll is reduced and the camber curve improves. The best result for those who say this is “racing stuff” is street drive ability. Tracking is improved greatly. No need to worry about ruts the road or constant steering correction.
Bergman Auto Craft has you covered.

 

[ckessel]

Thank you for the info Peter. While I'm thinking of it, have you worked with any of the drop spindles? Have any opinions of them?

 

[BergmanAutoCraft]

Thank you for the info Peter. While I'm thinking of it, have you worked with any of the drop spindles? Have any opinions of them?

I did years ago. The problem was it moves the suspension in the wrong direction, negating any benefit from a lower center of gravity. We use thin bump stops. With the correct height tires and set up there is absolutely no reason to use them.

 

[ckessel]

Good to know. I'll refrain from using them.

 

[Rennkafer]

Lower CG isn't the only benefit from dropped spindles. With dropped spindles you keep your control arms much closer to their original geometry. I haven't run any simulations on my B-body suspension, but I'd imagine lowering using the torsion adjusters doesn't do anything good for the roll centers or bump steer.

Peter, if you've run those numbers I'd love to see them.

 

[Kern Dog]

With dropped spindles you keep your control arms much closer to their original geometry.

Yeah? Why do you think THAT is a good thing?
As the suspension moves toward full compression, the caster and camber gains are excellent. Look at this chart:

At 2" below stock height, you've gained over 3 1/2 degrees of caster with stock arms.

 

[BergmanAutoCraft]

Lower CG isn't the only benefit from dropped spindles. With dropped spindles you keep your control arms much closer to their original geometry. I haven't run any simulations on my B-body suspension, but I'd imagine lowering using the torsion adjusters doesn't do anything good for the roll centers or bump steer.

Peter, if you've run those numbers I'd love to see them.

Not going to argue…Dropped spindles raised the height above what the factory had. Tie rod clearance is also a problem for wide tires. The key in improving geometry comes from a taller spindle package and improved alignment.

I’ve had every type of combination on my Dart. I speak from experience when I make suggestions.

 

[Rennkafer]

Yeah? Why do you think THAT is a good thing?
As the suspension moves toward full compression, the caster and camber gains are excellent. Look at this chart:

At what cost to roll center and bump steer though? There are usually better ways than lowering to gain caster/camber, like the SPC 2.0 upper arms Peter mentioned (which are on my "to buy" list.

This is why I asked if Peter had run kinematics on it.

 

[Rennkafer]

Not going to argue…Dropped spindles raised the height above what the factory had. Tie rod clearance is also a problem for wide tires. The key in improving geometry comes from a taller spindle package and improved alignment.

I’ve had every type of combination on my Dart. I speak from experience when I make suggestions.

Not trying to argue, Peter. I've also had a bit of experience on track over the last 43 years, including working on race cars professionally. I'm just asking for data.

What wheel diameter were you running when you had tie rod clearance issues?

 

[68 Sport Satellite]

Not going to argue…Dropped spindles raised the height above what the factory had. Tie rod clearance is also a problem for wide tires. The key in improving geometry comes from a taller spindle package and improved alignment.

I’ve had every type of combination on my Dart. I speak from experience when I make suggestions.

This is good info Peter. My 68 Satellite is 99% street car, but I tried to build it to handle. Not knowing much, I installed 2" drop spindles so I wouldn't need to lower the torsion bars as much to get the stance I wanted with the front fender lip at the top of the tire, thinking that this also with less torsion bar drop would keep my front spring rate stiffer. Can you tell me in layman's terms if this is hurting my street driving enjoyment compared to stock?

Can you explain more about the option you mention in Post # 1 and if it would serve me well on the street? When you first said taller ball joints the first thing I thought was that you're talking about drop spindles, but I see that isn't the case?

By the way, I'm running 275/60/15 Rear and 215/70/15 front. I would love to install same size 18" all around, but haven't convinced myself yet to make the change as I love the look of 15's.

 

[BergmanAutoCraft]

I ran into issues with tie rod clearance as I run a 9" rim on the front. The 6.38" backspace relies on being able to go around the outer tie rod and upper ball joint.

When you use the higher than stock suspension height with a dropped spindle, the tires are not square to the ground throughout the suspension travel. This is a basic explanation of camber curve.

Our 2.0 upper arms help mitigate this by allowing modern alignment specs due to their design and improved roll control from the taller upper ball joint. This is all benefit with no downside whether its street only or a performance application.

Going to 18s is all about you. I see many try this but miss the wheel offset or the tire height yielding a weird look. 15s are fine too in my opinion. In the front you could probably fit a 255 60 as well.

Let me know with any questions.

 

[68 Sport Satellite]

I ran into issues with tie rod clearance as I run a 9" rim on the front. The 6.38" backspace relies on being able to go around the outer tie rod and upper ball joint.

When you use the higher than stock suspension height with a dropped spindle, the tires are not square to the ground throughout the suspension travel. This is a basic explanation of camber curve.

Our 2.0 upper arms help mitigate this by allowing modern alignment specs due to their design and improved roll control from the taller upper ball joint. This is all benefit with no downside whether its street only or a performance application.

Going to 18s is all about you. I see many try this but miss the wheel offset or the tire height yielding a weird look. 15s are fine too in my opinion. In the front you could probably fit a 255 60 as well.

Let me know with any questions.

thanks for that info. I am running Firm Feel UCA's and have +4.5 degrees Caster and -1 degree camber. Besides your 2.0 UCA's, you are also running taller ball joints and F spindles. I don't understand what that means compared to my 2" drop spindles. Do you have some links you can share for the taller ball joints and spindles and let me know if they would work with my existing FF UCA's and provide any added or corrective benefit? I'm always willing to learn more, thanks.

 

[Kern Dog]

Technically, the component in this picture:

...Is a steering knuckle (With a slider type caliper bracket attached). The "spindle" is the part where the rotor or drum attaches. People seem to defer to calling these things spindles when they are actually knuckles.

I have two pair of the FMJ knuckles/spindles. They are 3/8" taller than the stock B/E/A knuckle/spindle. There was belief by some that the taller knuckle could result in the upper ball joint being at too much of an angle at full suspension travel. It has been proven numerous times to be false. The option of ball joints with a greater range of travel may be a good thing regardless.

 

[Kern Dog]

I have 18 x 9" front wheels with 4 1/2" of back spacing as shown here:

Outer tie rod clearance is not even the slightest issue with wheels this big.

 

[ckessel]

I have 18 x 9" front wheels with 4 1/2" of back spacing as shown here:

View attachment 1532425

Outer tie rod clearance is not even the slightest issue with wheels this big.

View attachment 1532426

Using Greg's photos, picture the wheel/tire/rotor 2" higher and you can see where the interference can happen at the tie rods. The reason I inquired about the drop units was if I pick up a wagon w/o d/b and want to do the swap, I already have a pair of the F/M/J units available in my stash, for my 65 which completion date is a couple of years away and I would get the drops for the 65. But getting feedback about geometry problems, I plan on doing track events with the 65, then seeing those pictures with the wide wheels, will be doing similar, shoots that plan dead. Nice to get feedback from those in the know so I don't waste money. I remember there was mention in Andy F's book about this, plus an article or two elsewhere, which refreshes my memory of what not to do.