Pontiac B body front suspension

[TheMonkey]

unfortunately, i cannot select new tubular front control arms for my '61 Bonneville (yet). anyone make custom arms?

would i be able to either box the stock front control arms, or weld in some webbing into the stamped channels to stiffen these up?

what has anyone else done to get these into positive caster territory? i was considering milling 0.150" off the face of the UCA shaft (currently > 0.750" thick), but don't like the idea of that. maybe rotate the towers that the shaft bolts to (worried about really screwing up the geometry though). or maybe something more radical to get away from rear steer?



imortantly though, orig Q is whether boxing or webbing the stock arms is worthwhile?

thanks,
Scott.

[astroracer]

Just a thought but compare the track width of your Bonne to some of the more common PT cars. F cars or G cars that have a lot of aftermarket support. If one of those suspensions compares favorably to your "space", do a swap. Doing a complete front suspension swap isn't all that difficult and it would get you into the land of "readily available high performance parts"...
Just thinking out loud...
Mark

[Marcus SC&C]

If you can get a few measurments for me (cross shaft bolt spacing,length cross shaft centerline to ball joint centerline and offset) we can do some adj. tubular arms for it. Then you can set the alignment where ever you like. IWe`ve done them for a an early B body before,if I recall correctly we based it on a 2nd Gen F body arm then changed it to suit. Modularity is cool! Mark SC&C

[TheMonkey]

thanks for the replies.

i think i need to do a lot more reading / research to better understand where i want this geometry to end up. i might be able to accomplish this without a full front end swap (although land of "readily available high performance parts" sounds pretty good to me).

i'm going to be down to the bare bones this winter. i would be comfortable relocating the UCA shaft mounts on the frame if i can get comfortable with where to shift them relative to where they are now.

mark - i checked out your website; your adjustable arms look really great. i'm wondering though... it seems that you can adjust the relative position of the upper BJ (caster range, and SAI), but i don't know if i have a problem with my roll center height. adjustable arms seem attractive if i can keep my shaft mounts in place, but i might be forced to start fabricating anyway to drop the mount height. although, continued adjustability after the welding is done is not a bad thought.

what about the orig Q.... does anyone have an opinion of additional stiffness over stock stamped arms could be felt &/or appreciated (assuming same geometry)?

thanks, Scott.

[shep]

Those arms are 40+ years old if nothing else add the bracing for safety and piece of mind. As for feeling it, I doubt that it would make that much difference.

[TheMonkey]

Those arms are 40+ years old if nothing else add the bracing for safety and piece of mind. As for felling it, I doubt that it would make that much difference.

when you say 'felling', are you referring to the vertical drop in the mounting? if so, why don't you think this would make much of a difference? it seems that this is a very normal update on cars from this era.

[astroracer]

Scott,
The SC&C arms will work fine for little changes but I doubt they will gain you much in the way of real handling improvements with your stock geometry and steering.
Moving suspension points around is NOT what you want to do. The issues you may fix (like R/C Hgt and Migration) are inconsequential when it comes to what you may do to the steering geometry. Bumpsteer, ackerman and anti-dive will all be affected when you start moving control arms around without taking the steering into account.
This is why I suggested a complete front clip swap. Putting in a complete, known suspension, removes all of these variables. Your options after the swap would be endless but I think the addition of the later model geometry and disc brakes (after a rebuild) would be so far above what your current suspension can do that you would be happy with that for a while... You can do this swap for very little money, initially, knowing that what you are doing will work and then, once the car is up and driving, make improvements as time and money see fit.
I don't know what you are planning for an engine but this swap will work with any BBC or Pontiac block and, with a little work on the motor mounts, will except the stock motor in your Bonne'.
Just some stuff to think about.
Mark

[TheMonkey]

thanks Mark.

an entirely new front end is a bit more than i was anticipating, but i will explore it. i suppose as long as i'm down to the bones anyway, now is the time to address it.

really though.... how noticeable is the difference in handling & driving enjoyment between '61 rear steer vs. something with later style engineering? i mean, i believe it exists, but worth the time/effort/headache of a swap of this magnitude?

my frame does not have a removable front subframe, so i would think that adds to the complications. there is a front subframe from a 1980 TA that i know of locally. i'll do some measuring, and consider how this might mate. i'm going to be at the restoration shop next week to discuss body work, so i'll ask them their thoughts on this approach for the frame too.

motor being built is a Ponch 455.

thx, Scott.

[astroracer]

really though.... how noticeable is the difference in handling & driving enjoyment between '61 rear steer vs. something with later style engineering? i mean, i believe it exists, but worth the time/effort/headache of a swap of this magnitude?

Well, Scott, that's what you have to ask yourself... The biggest question is, what is the final use of the car going to be? Race track? Street racer/corner burner? Cruiser? If it's a driver, on the street, what are your expectations? Is doing all of this going to be "better" then a simple bushing swap (to poly), better shocks and a good sway bar? You would be surprised what a moderate lowering, high performance low profile tires and a good set of shocks will do.
Yea, I know, front steer/rear steer/positive camber gain/roll center migration.... On a RACE car all of this stuff is important. For a street car, where getting on the expressway at 70 mph instead of 65 is your only gauge, does it really matter? I'm not trying to flame you here, I just want you to stop and think about what is important for YOUR car.
If it's not a race car I would suggest simply rebuilding the current suspension and adding a few bolt on Hi Perf parts. And remember, whatever you do in the front needs to be reflected in the rear to keep the car balanced.
Mark

[TheMonkey]

.... I'm not trying to flame you here, I just want you to stop and think about what is important for YOUR car.
.....

Mark- no worries. i appreciate the critical thinking.

.... If it's not a race car I would suggest simply rebuilding the current suspension and adding a few bolt on Hi Perf parts.....

on a '61 convertible i have with the same front end: new springs + kyb shocks + fat sway bar was an amazing improvement over stock. although, after that, i put a new front end bushing kit on with disc brakes and new rims/tires. and it was terrible with the 245/45/17 tires. center of tire line pushed out only by 3/8", but the wide tires accentuated everything, and the car hunted all over the road. i tried factory spec negative caster, and could only get close to vertical on adjustment. i'm not sure if more positive caster would fix that issue entirely, but i know that some work has to be done beyond just bushings, bar, etc.

....And remember, whatever you do in the front needs to be reflected in the rear to keep the car balanced.
Mark

what do you mean? do you have any examples?

[astroracer]

Wide tires on a rear steer... I see where you are coming from. Input is amplified and the rear steer doesn't like to center itself like a front steer will with a little additional caster.
As far as the rear goes, don't update the front without updating the rear. Poly bushings up front vs. worn out rubber in the back won't help the handling... That's all I was trying to say.
How about a frame swap? Early to mid 90's Caprice/Impala SS... You may be able to adapt the front steer components to your chassis BUT, again, it depends on how important it is to you...
Do some part number searches on an on-line parts house. My Astro Van uses the same steering knuckle as the later '77 on up "B" bodies. Check ball joint and bushing numbers between your '61 and a '91 Caprice, you may be able to do some judicious parts swapping...
Mark

[Tony@AirRideTech]

Now on some of the Pontiac B body cars... If I remember right, if they are a candian built car it is very likely that it has a Chevrolet chassis under it like what is found under the Impala, BelAir Biscayne. We even had a 58 pontiac wagon once that was like this. On the other hand, it may be like the 61-67 Buick Chassis too.... does your car have a boxed style lower control arm and use a forward mounted strut rod?

[Marcus SC&C]

Scott, Marks makes some good points but I don`t get the sense that you want to chop the car up and make it into a road race car. You just want it to drive and handle a lot better than it does now (comparable with a decent new car) yes? The adj. arms won`t do much at all for the geometry but they will do a lot for the alignment. Rear steer or not we`ve found some + caster and - camber to have noticable benefit on rear steer Camaros and Novas. I`m not talking theory here,I just realigned a `69 Camaro ragtop with modern perf. specs yesterday. We do it all the time. Since we don`t have all the numbers we don`t know if it`ll effect the bumpsteer for better or worse but the effect will be slight either way. I`m not familliar enough with those cars to tell you what would help the geometry but if you want to get into it a little give me a call. With a few measurments it`s easy to tell the basic trends the front end and steering follow and tweak it to make it much better,if not perfect. We`ve gotten pretty good geometry out of a `46 Plymouth front end (the mother of screwed up front ends!) with a few tweaks and carefully chosen parts. That thing was so bad Suspension Analyzer wouldn`t let me enter the specs in stock form,it kept flashing ERROR! ERROR! Bear in mind that 2nd Gen F body and B body front ends aren`t without their problems either. There`s a lot of different ways to go,a good clean sheet custom front end would be awesome but tweaking the stock front end will give you the best bang for the buck. Mark SC&C

[pitts64]

I wonder what type of suspension mods they did to the NASCAR Pontiacs of this period (61-64).
I wish I had concrete answers for you Scott but it seems we are both at the same point here with our B bodies.
My suspension guy didn't recommend adding positive caster either.
I think he said something about adding a little more negative camber.
When I remove my control arms this winter I'm going to look into Del A lum bushings.
From what I "hear" about Poly, its OK for the front but no good for the rear.

[TheMonkey]

Now on some of the Pontiac B body cars... If I remember right, if they are a candian built car it is very likely that it has a Chevrolet chassis under it like what is found under the Impala, BelAir Biscayne. We even had a 58 pontiac wagon once that was like this. On the other hand, it may be like the 61-67 Buick Chassis too.... does your car have a boxed style lower control arm and use a forward mounted strut rod?

yes, the canadian versions were on chevy chassis, and came with the chevy motors too. the big advertising push for pontiac in '61 was the new 'widetrack' which was only on the US cars.

i'm not sure what you mean by fwd mounted strut rod.

Scott, Marks makes some good points but I don`t get the sense that you want to chop the car up and make it into a road race car. You just want it to drive and handle a lot better than it does now ....

yes, this is true. but remember, i'm at a bare bones frame. if i do all my research now and explore opportunities, it might not be that big of a job, except i may run into other headaches when hanging the sheet metal.

i found an example of Steve Barcak from Pontiac Heaven in Arizona had put a 73-77 Grand Prix front clip on a '61. i'll talk to him a bit about this.

...
When I remove my control arms this winter I'm going to look into Del A lum bushings.
From what I "hear" about Poly, its OK for the front but no good for the rear.

my '61 has metal on metal bushings on the tops, and rubber on bottom. if i keep the original front end, i'd prob put firm bushings on bottoms, move the UCA mounting holes back about 3/8" for caster. maybe put on adjustable arms with firm bushings up top if more adjustability is desired in the SAI.

i am going to box my rears and keep rubber.

we'll get it figured out. i knew coming into this that resources are not as plentiful for us, but it makes for more of an adventure.

[pitts64]

Scott, did you check out Indian Adventures Ground Grabbers?
http://gallery.bcentral.com/GID47169...tion-Bars.aspx

[TheMonkey]

Scott, did you check out Indian Adventures Ground Grabbers?
http://gallery.bcentral.com/GID47169...tion-Bars.aspx

Yes this is an adventure. You need more then a pocket full of money with these cars!
http://www.youtube.com/watch?v=lDofS1BXlYM

the ground grabbers are on perpetual backorder. IA keeps waiting on the bushings, i'm not sure why they don't tool around some more available bushings. i think they only come with poly.

i have heard that boxed stockers work great, and i *think* i want stiff arms with rubber bushings in back.

thanks for sharing the vid. very cool. listening to a tuned 462 is a great way to start the day. cars like that are the reason i've fallen under the spell.

[pitts64]

I think we need to post some detailed suspension photos with measurements so the experts here can help us.


Are you going to Norwalk next year?

[Tony@AirRideTech]

i'm not sure what you mean by fwd mounted strut rod.

See attached......

[TheMonkey]

Are you going to Norwalk next year?

i don't think next season is going to happen, but i think it's in my future. you will be there? are you driving your car out?

Tony- the pontiac does not have the strut rod. both upper and lower control arms are A style, and the only other linkage is to the sway bar.

maybe i'll scan in a couple pages out of my service manual tonight that shows the suspension setup.