Pontiac B body front suspension

[pitts64]

Here are some photos I found.

[Marcus SC&C]

The parts and geometry look a lot like C2/C3 Corvette. Best I can tell from the pics the pickup points of the upper and lower arms are roughly parallel (maybe down a little at the ball joints?). RC height should be above ground (a good thing) but camber gain is probably almost neutral. C2/C3 cross shafts are probably the same spacing. That would make adj. arms easy and that would take care of the alignment. Stingrays and shoebox Chevys with roughly similar geometry respond very well to taller upper ball joints. The higher roll center helps reduce body roll and the - camber gain helps keep the tires planted with the roll that`s left. Later B body suspension isn`t really much better than what you`ve got by the looks of it. Mark SC&C

[pitts64]

The main thing I'm after is better straightaway feel. I'd like my car to be harder to turn out of the center (straight).
My car (64 bonneville) handles bends well.
I installed a AGR 12 to 1 box and big Addco front sway bar.

[pitts64]

Monkey are these what your looking for?
http://cgi.ebay.com/ebaymotors/ws/eB...0621&rd=1&rd=1

[TheMonkey]

i would say that is a similar sensation to my convertible '61. it drives straight, but you better keep your hands on the wheel. it doesn't 'float', it 'nibbles'.

which all kind of spells out: more caster.... doesn't it?

[TheMonkey]

Monkey are these what your looking for?
http://cgi.ebay.com/ebaymotors/ws/eB...0621&rd=1&rd=1

those look like a one-off fabrication that will require a bit more fabricating for bushings. i know that i don't want metal on metal. the catalina is a bit shorter on the back end than the Bonneville. i'm not sure that they have the same RCAs.

i think the stock ones will be fine with some reinforcement. i already have 8 new rubber bushings for them.

[jaybee]

Marcus, can you expand on the "taller upper ball joint" comment?

[pitts64]

The control arms are all the same.
You might want to give each bushing a little tack to keep it in place.
Too bad you can't get the Indian Adventures bars. They are very nice. They have two angle adjustments, one for automatic and one for stick cars.

[67 caprice]

[quote=TheMonkey]. anyone make custom arms?

/quote]
http://www.performanceonline.com/sto...cat=715&page=1
THIS IS FOR A CHEVY B BODY 58 - 64
IT SHOULD WORK FOR YOUR 61 BONNEVILE

[67 caprice]

[quote= anyone make custom arms?/quote]
http://www.performanceonline.com/sto...cat=715&page=1
THIS IS FOR A CHEVY B BODY 58 - 64
IT SHOULD WORK FOR YOUR 61 BONNEVILE

[Marcus SC&C]

Jaybee, using taller upper ball joints extends the effective spindle height and changes the angle of the upper arms. This changes the camber curves and due to the way the arm`s angles interact with each other it also raises the roll center which generally reduces body roll. There`s a lot more to it than that but that`s gist. We use CNC machined modular ball joints that let us change the pin or stud height to make the changes we want. On these cars we can do a 3 bolt flange joint but the extra height may make it a little harder to get a performance alignment out of it. On `55-`57 Chevys and C2/C3 Vettes we use the adj. tubular upper arms to eliminate the alignment issues and a more common 4 bolt Chevelle housing to fit the arms. That would be the easiest way to go on these cars as well. I can tell you from experience the extra + caster,a little - camber makes a BIG difference on this type of front end,we do this sort of thing all the time. The tall ball joints won`t make any different cruising down the highway but you`ll get noticably less body lean in the corners and much better mechanical grip from the tires. Big cars that handle are cool. Mark SC&C

[pitts64]

Mark, I e-mailed you about the adjustable uppers with the tall ball joint.

[TheMonkey]

Mark-

does a taller BJ have the same effect as lowering the mounting holes of the shaft?

as i think about it, the adjustable arms may be my route also. even if a taller BJ was avail for the stock arm, caster is still a problem.

Mark - your arms can back the BJ up into positive caster? i think i need 1/2" or more. more if i want to play with a couple degrees.

here is a pic of the '61 UCA. note that the BJ is actually slightly fwd of the front bolt. not sure that Jeff's '64 is the same. **** EDITED to add that i wrote this wrong... the BJ is slightly behind the rear bolt; wrote it backwards *****



thanks.

[Marcus SC&C]

Yep,lowering the cross shafts or raising the upper ball joint pivot points have the same effect. If you can confirm the cross shaft bolt spacing (looks like 5" from the pic) and the distance from the centerline of the cross shafts where the mounting bolts pass through to the centerline of the ball joint (grease fitting hole) I can whip up a set of arms no sweat. In plan view it looks a lot like an early Camaro arm,but longer. The offset is no problem early Camaro arms have a similarly extreme offset (facing the other way,Jeff`s looks like it has offset similar to the Camaro). Each leg of the arms adjusts roughly 2" so you can try just about any caster setting you want. Mark SC&C

[jaybee]

Very interesting as I was prepared to go exactly the opposite direction. Nova ball joints are considerably shorter than Tri5 units. By substituting the Nova ball joint you can fit a wider wheel with more backspacing, because the stock piece sticks up next to the wheel rim whereas the Nova unit will fit inside a 16" or larger wheel. I don't think relocated inner mounts will work on a 55/6/7 with stock control arms as the UCA runs too close to the spring cup and the suspension will top out early. I'm not sure if the same is true of the later B-body cars, but it looks very similar in the pics.

[TheMonkey]

Mark-

Pitt64 & I both have the same front disc brake conversion, and it sounds like we have similar handling problems - straight away feel.

I do want to get caster back, but I did some other measuring this weekend. I measured the effect of scrub radius of the stock drums vs. the new discs. The new discs push the scrub radius outward (increase) by 5/8", and I did not compensate for that with the offset in the wheel.

I would prefer to keep offset where it is, because I have the same wheels front to back so i can rotate, and the back is a glove like fit. Also, I already own these wheels.

So, here's my question.... if I put on some adjustable arms, and pull the upper BJ inboard a bit to increase the SAI angle, and reduce scrub radius... that could fix scrub radius, but what would the increase in SAI angle do?

I think that the upper BJ would have to get pulled in more than 5/8" because the height difference between upper BJ & lower BJ is more than the height difference between lower BJ & the ground. But anyhow, I think it would help to reduce scrub radius, I'm just not sure what an increase in SAI will do to handling?

Thanks, Scott.

[TheMonkey]

Duh... SAI can't be changed without a new spindle right? Pulling in upper BJ just changes camber.

The only fix for scrub radius is changing the offset in the wheel I think.

[TheMonkey]

Unless I weld on another BJ hole onto my spindle just inside the existing hole. Suppose I could raise it, and put it more forward on the spindle at the same time too.

[Marcus SC&C]

You kinda answered your own question. The problem with welding to those spindles is that they`re ductile iron, not steel. That is not to say that you *can`t* weld to them at all but that the welds almost certainly wouldn`t be up to the job at hand. I wouldn`t try it. Looking at those pics I can see what you mean about the SAI and scrub radius though! That`s pretty bad. A lot more backspacing would the be easiest way to improve the scrub radius issue. Of course it looks like you`d also have to get larger dia. wheels to clear the upper ball joint/UCA. You know how it is,whenever you change one thing.... Mark SC&C

[pitts64]

Wanted to bump this thread up.

Scott I was wondering how far along you are with your projects?