59 GM X frame rear suspension theory

First off i'll give a little background on the suspension set up we are proposing and on what it will be implimented. We have been collecting cars for the last couple years in order to do a few builds in tandem as it works out a little more efficient that way and I came up with a (I think) new idea for rear suspension and i wanted some biased opinions on possible problems and general thoughts on the concept.

The projects

-59 Impala landspeed racer(dedicated purpose built salt flat car)
-59 El Catalina (Canaidian version of pontiacs (prototype)
-59 Pontiac wagon (Heavy Duty period tow rig for saltflat car)

The idea for the suspension came to me while working on the 58 biarritz on the weekend and staring up at it"s X frame while running all the logistics in my head for the wagon suspension and drivetrain. Plan is to install the 60-72 chevy truck trailing arm rear suspension to the x frame. The stock arms geometry places the forward mounting point of the arms directly at the narrow center spine of the x frame. The wide rear of the frame will alow for a long panhard bar like they used when this suspension was adapted for Nascar.

Here are the basic set ups for the rest of the three cars just incase anyone sees a conflict with this setup on any of the builds

Impala land speed car
Planning a built 348 induction will depend on rules and classes, th400 with gearvendors and 2 speed ford nineinch. stock front suspension

El Catalina
we have a good 59 ElCamino, canaidian pontiac front end bolts on, doors are same, 2 door quarters streatched out with the wagon gate and corasponding tail pieces. We have to change the back part of the frame to acomidate the wagon rear bumper but not a biggie as canaidian pontiacs had chevrolet drivetrain and underpinnings. 400 smallblock trimed to look period, auto and a twelve bolt. this will be a daily driver shop truck as it is currently.

59 Pontiac heavy duty tow wagon
This is where the idea spawned from, looking to swap a 8 bolt pattern rockwell from a 70 gmc 3/4 ton with the detroit locker which is comming from a trail arm truck. measured up the front and the pontiac frame width is the same as 73-87 chev 3/4 ton 2wd and height will work well to slip the whole front crossmember in and run the 8 bolt discs and big sway bar. thoughts have rolled around of using the 14 bolt from same truck in place of rockwell. drivetrain for now will likely be a super low mile 500Ci caddy engine with new th400 because it will work and we have it.

 

Here is the Impala and parts car, there are many more parts from cars we already striped, the Elcamino and some of the pontiacs we gathered.

 

Pics of Elcatalina we are cloning, the better wagon and another of camino

 

We already did the 4dr HT familly hauler

 

other side of good wagon and parts wagon.

 

After measuring it all up it looks like a no brainer. I havent seen it done yet though and wonder why. anyone think of issues to look at from experience adapting truck arms to other cars?

 

^^^^^^^^^^^^^^^
I want some of what you're smoking,LOLOLOLOLOLOLOL!!!!!!!!!!!!!!!!!!!

 

Man after the caddy I just finished these three should be a cakewalk.
http://forums.aaca.org/f190/1958-cadillac-eldorado-bairitz-317242-5.html

 

give it a try - maybe we all can learn

 

Greetings! Time for a re-think. First off, using the truck trailing arms for your LSR rear suspension is a great idea, but only if you build a frame to go with them. I would dump the original "X" frame in a heart beat, if only to make installing a roll cage easier and get away from having to use a carrier bearing on the drive shaft. Also, truck suspension under your wagon won't work, the track on the wagon is around 60" wide, the truck 65" wide (info from the internet). If you want heavier suspension and free disk brakes for your tow wagon, clip the front using the front frame stub from a 91-96 "Jellybean" Caprice (which uses truck spindles so aftermarket drop spindles are easy to find), I'd swap the rear end too so the bolt pattern would match (big pattern chev), the best choice for donor parts is a former police car as they had thicker sway bars and posi rear ends.

 

We drag raced a 59 El Camino about 10 years ago. It had an iron head BBC
with turbo 400 w/brake it weighed 4200# and would run low 11's. It normally
left with the left front wheel about 8-10 inches in the air due to twist. It had
a single piece driveshaft and a 9" ford rearend w/ 4.56 gears. We installed a
8 point rollbar in the car with 6" steel plates welded to the rocker boxes and the
center hump, since it was like installing them in a unibody car.
I would get a SCTA rulebook and check with the tech dept. I'm sure the
rollcage you build will have to be attached to the chassis to be legal and without
building an entire perimeter frame under the 59 floorpan, there is no way I can
see a real rollcage being safely installed in a GM X-frame car.

 

Front 12" disc brakes are just a C2-3 Corvette away, and they bolt on..............

 

tell me more please , i have searched and searched and never heard of this

 

The "X" frame on a GM car doesn't allow itself for many radical modifications. I shortened a '55 chevy 4 door wagon and the frame was a breeze to do. The '55 ended up a 13' long two door. Then, I got a '59 Cadillac Sedan de Ville. I wanted to shorten it too. Got a model first and shortened it to get an idea of what I 'd be in for. Model came out okay. Made me realize what a challenge the "X" frame presented. Changed my plans, sold the Caddy. Built two Triumph rigid frame bikes instead. I now wish I had dealt with the "x" frame and shortened the Caddy to a two door convertible. When there is a will there is a way. You can always subframe too. Done that a few times. Good Luck in whatever you decide to do, and post pictures of the progress.

 

'59-'68 chevy passenger car spindles are interchangable (ball joints and the location of the ball joints are the same), with C2 vettes, C3 vettes-used larger wheel bearings, (good idea in a 59 chevy), and need the hubs to go with.
so as a set c2 bolt on, c3 bolt on, but don't get c2 spindles and c3 hubs.
caliper brackets are the same c2/c3, calipers are same, rotors are the same.
So remove the 59 spindles/brakes, install the Vette parts, use a Vette master cylinder, plumb for the dual master, front/rear.
i have parts, PM me if you want.

i used to install the vette parts on 55-56-57 chevys also.....

 

...does the brake conversion to c2-c3 make the wheel track wider?....& don't the 4 piston calipers almost always need to be sleeved w/ stainless steel?

 

I think the truck arm suspension should work pretty well under an X frame Chevy - I was considering doing the same on my '60 El Camino when I switch out the rear for a 9" Ford. I've roughly measured it up and it does seem like the arm length is about right to meet the narrow part of the frame so the geometry should work out ok.

My biggest concern is making strong enough brackets since they'd be hanging off the side of the frame rather than from a crossmember like the trucks have. I believe Cody Walls has a custom 2 link under his '59 Wagon so it might be worth finding out how he made his brackets.

It'll be a while before I get to my El Camino so in the meantime I'll be watching this thread with interest hoping to pick up some tips.

 

Got a SCTA rule book on order, That was my first step towards the LSR, plan is to make it fit as many classes as possible and build towards the upper limits of the safety requirements so it is more easily upgraded as it evolves. Done reverse builds before and learned the hard way playing drag racer. Just build it to the book from the start and build in expandablity. I have heavily researched the usage of X frame cars in early NASCAR and have picked up a few cage ideas from some of Smokey Yunics work but not sure how his cage designs translate to SCTA but he built them around stiffening chassis. Junior Johnson apparently Ran truckarm suspension in his 63 impala but despite the fame of the car all the hype about his GM mystery motor has drowned out any and all suspension info.

We will see where the center drive truck arm set up goes, I'd really like to try it on at least one of them. I kinda have a thing for that setup, It will probably be the wagon as it will be the kinda low buck, use up all the spare parts kinda unit.

I also had concern of the flex issue. I restore cars for a living and seem to keep ending up doing x-frames, especially convertables. Always hated them for the flex. Got a pretty good handle on building the body to reinforce the frames. We press brake inner and outer rockers in 1/8" or 12g and run them through to leadi g edge of rear wheel well openings instead of stopping at rear edge of door, like this( http://forums.aaca.org/f190/1958-cadillac-eldorado-bairitz-317242-4.html posts #36 and #44) Wagon has a rotted floor I could make new floor braces extra beef to help when I repair it.

A lot or real good points brought up though. I like the idea of some of those brake ideas. Might do something like that for el Catalina. It will be a quick build to bang out seeing as camino is decent to start.

As far as the kinda out there truck arm idea I had though about atatching all mounts to a 1/2 plate that attaches to bottom of frame that would tie in to sides of x and atatchment points further forward and behind so it stiffens but still flexes. I have a lot of off road rock crawling buggy experience to draw from on design and I think I may even be able to do a stand alone, bolt on plate crossmember that mounts the arms, sandwiches and cradles the X while picking up the frame I front and behind the X. I built one just like this a a stiffiner for the chassis of pro tour 60 olds that the customer wanted to auto X and it smartened it right up.

If that design could be expanded upon and it worked, it could possibly be a pretty slick bolt on center drive option for X frames.

Also thought about developing a bolt on DOM tube "subframe connector" that would pick up the cowl mounts and run behind the rocker area picking up more body mounts further back. It would bolt on in place of washers on body mounts and pick up 3 body mounts. The idea came from a temporary brace set up I made so when I sent restored X frame convertables out for sublet work where shops only had 2 post hoists they could raise it without fear of rippling floating quarter panels when flexed on hoist. Mine were 3/8 wall DOM which would be far to much and they hung down and were visible but I know I could make some lower profile ones that could tuck. Adapting those may help too, maybe tie them into center plate frame for extra strength, key would be to get as light as posible while not losing strength.

Just kinda throwing around ideas at this point but its keeping me up at night.
Have acces to CNC plasma and waterjet to speed trials so I may give it a poke just to see and do some mock up.

Thanks for all the input.

 

Shame you can't find any info on Junior's '63, that would be very interesting.
I like the idea of the plate mounting setup, sounds like it could work pretty well.

Another brake option for the front is using late '60s full size Chevy spindle. I've got '68 Caprice 4 piston brakes on my El Camino and other than drilling out the steering arm to fit the larger bolts on the caprice spindle it's a bolt on. I bought new calipers from Rock Auto which weren't horrendously expensive but could probably have doen a CPP or similar conversion for the same or less money. The 4 piston calipers are cool though

 

I googled the hell out of juniors car to the point where I feel exempt from shame. I came up with several sources listing it as the first known usage of the set up in NASCAR in 1963. That means no pre 63 and gm had the racing ban in effect by 64 so that car is gonna be the only NASCAR with truck arms if it even really had them, found forum posts saying it didn't but half the guys on forums are full of crap so it's still posible. They built a clone but may not have cloned suspension. Can't find anything on it at all but it's likely to be true as junior ran truck arms in his galexy a couple years later.

 

All you need to do is put anti roll bar on the rear-end and that will eliminate all the twist in the car and no need for trying to square the frame in

 

We picked a 1964 Pontiac Wagon to go LSR . This was our first year and went 144 at Loring and 142 at the Ohio Mile . The car was stable all the way up and down with only new bushings and new springs and shocks.
Got my SCTA rule book yesterday . I,m sure a capable person can cage it to pass tech but I,m all ears if anyone has a plan. We're not going to get in B Ville record books with that body style . So we built it to be safe and fun .
My opinion is that the stock suspension works pretty good forLSR

 

What you running for power in the 64 Pontiac? Pics?

 

The car is Stratochief Safari -Canadian production they came with Chev engines ours has a 355 with a650 carb, 3.36 diff . There is more speed to come but we are offside now without a cage.
I can't move photos but there are some on the LTA site from the July meet and maybe the Sept Ohio mile.
Bigger sway bars would help a lot there is turn to get unto the return road.

 

the 59 -60 olds used a perimeter frame, but the body is basically the same (windshield ,cowl, rear window...) as the x frame cars. they used a leaf spring rear. I wonder if that would be a better frame to start with? for the lsr.

 

The twist is from drive train torque. The convertible frames had perimeter bracing. 55 - 57 Chevrolets were popular as stock cars but hardly anyone tried using 58 - 64 models in stock classes because of the rules for a stock frame.

 

That's cool, all ours are Canadian Pontiac's as well. Dragged most of them back to BC from Saskatchewan

 

You need to pick a SCTA class before you turn a wrench. Plus, that big boat will hardly be competitive. We know how tough it is with the Unibody and a vintage engine. LSR is expensive, do you want to spend thousands upon thousands just to go and run hot laps?

 

I agree.. I had a dream once about building a 60 Bonneville sedan for lsr, chopping the top WAY down to get it out of the breeze, and some ideas to make the front more aerodynamic... then to power it, 2 Pontiac 455's side by side right behind the dash....
that is something I might have been able to build and run if it was 1960 or so, but after a look at the current rule book, there would be no way to run something like that.
actually after checking out all the rules and classes, I had pretty much no interest in trying to build anything that could run their event.