Suspension TECH Including Brakes, Wheels and tires

          
Reply
 
Thread Tools Display Modes
  #41  
Old 04-27-2023, 01:03 PM
rolling money pits's Avatar
rolling money pits rolling money pits is offline
Ultimate Warrior
 
Join Date: Jan 2005
Posts: 1,541
Default

My ADD is kicking in big time…

Toying with the idea of coilovers, and as such looking at tubular LCAs. Does anybody make a tubular LCA that are designed for/can accommodate both factory springs and a coilover set up? IF, and that’s a big if, I do go coilover I’d use the hybrid style which locates the upper part of the spring in the factory frame pocket.

I currently have, I’m guessing, the first iteration of GWs negative roll uppers, purchased in 93 or 94. Late 2nd gen F body spindles, with factory LCAs.

Thx

__________________
costs too much
  #42  
Old 04-27-2023, 01:24 PM
LKLusza's Avatar
LKLusza LKLusza is offline
Member
 
Join Date: Oct 2019
Location: Clarks Summit, PA
Posts: 70
Default

Interesting thought. I'm not aware of lower control arms from anyone that can do double duty like that - sorry. All the ones I've seen are of "either/or" type construction.

__________________
Larry
  #43  
Old 04-27-2023, 02:38 PM
ZeGermanHam's Avatar
ZeGermanHam ZeGermanHam is offline
Ultimate Warrior
 
Join Date: Nov 2016
Location: Seattle, WA
Posts: 1,924
Default

The tubular control arms sold by UMI Performance can accommodate regular springs and coilovers, and I suspect many others can as well.

https://www.umiperformance.com/home/...front-arm-kit/

__________________

1966 Pontiac GTO (restoration thread)
1998 BMW 328is (track rat)
2023 Subaru Crosstrek Limited (daily)
View my photos: Caught in the Wild
  #44  
Old 11-07-2023, 02:08 PM
chiphead's Avatar
chiphead chiphead is offline
Ultimate Warrior
 
Join Date: Nov 2004
Location: Aiken, SC
Posts: 5,182
Default

Bumping this as opposed to starting a new thread-

It's time to replace the front suspension in my '67 LeMans. Main use is backwoods highway carver, some interstate commuting and occasional pass at the dragstrip for grins. 400/TH400/3.25 ford rear. Eventual swap to a built 434. Rear suspension is adjustable uppers, boxed lowers, wagon springs on a Ford 9" rear.

What kit would you guys recommend when using traditional coil springs? Plan on installing heavy front and rear sway bars at same time.

__________________
I could explain all this to the girl at the parts store, but she'd probably call the asylum.

White '67 LeMans 407/TH350/Ford 3.89... RIP
Red '67 LeMans. 407/TH400/Ford 3.25
  #45  
Old 11-07-2023, 04:02 PM
Joe-Touring Joe-Touring is offline
Senior Member
 
Join Date: Feb 2022
Location: Western WA
Posts: 123
Default

Quote:
Originally Posted by chiphead View Post
Bumping this as opposed to starting a new thread-

It's time to replace the front suspension in my '67 LeMans. Main use is backwoods highway carver, some interstate commuting and occasional pass at the dragstrip for grins. 400/TH400/3.25 ford rear. Eventual swap to a built 434. Rear suspension is adjustable uppers, boxed lowers, wagon springs on a Ford 9" rear.

What kit would you guys recommend when using traditional coil springs? Plan on installing heavy front and rear sway bars at same time.

I have SPC springs and upper/lower arms up front, highly recommend. The lower arms will work with either setup, but with coil springs I’d purchase their shim kit to be able to adjust ride height. With the SPC springs I used all the shims to get my height perfect, still pretty low, but I have a tall lower ball join so that’s another 1/2 inch.

I went with the Delrin bushings and they are
S M O O T H. The big reason I went with SPC is the adjustability in the uppers, no more shims. The alignment guys love em, saves em a lotta work.

__________________
67 LeMans, 326, M20, 3.31 12 Bolt
  #46  
Old 11-07-2023, 04:19 PM
JLMounce JLMounce is offline
Ultimate Warrior
 
Join Date: Sep 2005
Location: Greeley, Colorado
Posts: 3,679
Send a message via AIM to JLMounce
Default

I second the SPC parts. One of the biggest benefits is not having to deal with shims, which on a Pontiac engine really frees up a good bit of room to get your alignment right.

Only issue is that SPC does not make control arms for the rear of the car. I'd probably go with the UMI rear arms personally.

If I was going ultimate with standard coil springs I'd do the following:
SPC Front Upper and Lowers with SPC coils front and rear
Speedtech ATS Spindle
SPC shim kit to adjust ride height and their progressive rate jounce bumper
UMI Fully Adjustable rear control arms
Helwig front and rear sway bars

Matched with as wide of a tire as you can fit in the wheel wells, that setup will carve some corners. Add a Lee or Turn 1 steering box and appropriate power steering pump as well.

There's a bit of money in that set up above however. If the budget isn't there for it, priorities the rear control arms, followed by the springs and a front sway bar. I'd opt out of the ATS spindle and run a .5" tall ball joint on the factory spindle. This will get you about 75% of the way there.

__________________
-Jason
1969 Pontiac Firebird
  #47  
Old 11-07-2023, 04:46 PM
Joe-Touring Joe-Touring is offline
Senior Member
 
Join Date: Feb 2022
Location: Western WA
Posts: 123
Default

Quote:
Originally Posted by JLMounce View Post
If I was going ultimate with standard coil springs I'd do the following:
SPC Front Upper and Lowers with SPC coils front and rear
Speedtech ATS Spindle
SPC shim kit to adjust ride height and their progressive rate jounce bumper
UMI Fully Adjustable rear control arms
Helwig front and rear sway bars
This is almost exactly my setup, less the AFX spindles. I elected to run with tall upper and lower ball joints. I probably didn’t save much because I ended up with C5 brakes, which I believe bolt right on to the AFX spindles.

Anywho, I also changed over to a Jeep Grand Cherokee steering box, majorly beneficial to steering feel. I’ve surprised many people who thought you can’t make an old muscle car handle.

Highly recommend, with Bilstein shocks, the ride is decent.

__________________
67 LeMans, 326, M20, 3.31 12 Bolt
  #48  
Old 11-07-2023, 10:52 PM
chiphead's Avatar
chiphead chiphead is offline
Ultimate Warrior
 
Join Date: Nov 2004
Location: Aiken, SC
Posts: 5,182
Default

So explain the tall ball joint thing? When do you use tall upper, tall lower, both together, etc?

The spindles and brakes I have now are factory single-piston disc brakes. A PO did the disc brake conversion. I think the donor was a late 60s, early 70s F body. The brake hoses that fit are for a '69 firebird. Will that work with the aftermarket arms?

Will these arms accept typical coil springs or do you have to get them from SPC? The car has lowered drag-type springs that gotta go. I'd like something closer to stock ride height but have no baseline. Being able to add/subtract spacers from the front would be a killer feature.

Is it possible to replace the upper control arms with engine and headers in place? Thanks for all the input

__________________
I could explain all this to the girl at the parts store, but she'd probably call the asylum.

White '67 LeMans 407/TH350/Ford 3.89... RIP
Red '67 LeMans. 407/TH400/Ford 3.25
  #49  
Old 11-07-2023, 11:08 PM
gtospieg gtospieg is offline
Ultimate Warrior
 
Join Date: Apr 2012
Posts: 1,225
Default

You should be able to remove upper control arms with the car together. Sometimes the steering shaft will block the control arm. You may need to drive the bolts out to gain clearance.

  #50  
Old 11-08-2023, 12:15 AM
OG68's Avatar
OG68 OG68 is offline
Ultimate Warrior
 
Join Date: Dec 2011
Location: Chula Vista, CA
Posts: 1,475
Default

And the upper control arm mounting bolts are splined to the frame. Don't attempt to remove them with a ratchet or impact. Tap them out with a small hammer.

__________________
Ed

1968 GTO (Thanks Mom)
2006 Silverado
2007 Cadillac SRX
2015 Chevy Express

  #51  
Old 11-08-2023, 12:35 PM
Joe-Touring Joe-Touring is offline
Senior Member
 
Join Date: Feb 2022
Location: Western WA
Posts: 123
Default

Quote:
Originally Posted by chiphead View Post
So explain the tall ball joint thing? When do you use tall upper, tall lower, both together, etc?
From what I understand, the tall ball joint(or tall spindle) gains more negative camber, quicker.

The short/long a-arm setup that GM used thru the 60s-70s is a very good base for handling performance. The factory geometry is terrible, however. GM engineers setup the front a-arms and alignment specs to massively understeer(read: not grip). When you go thru a turn, the outside suspension compresses. What you want to happen is have the top of wheel/tire tuck inboard(gain negative camber). What happens with the factory arms is the opposite: positive camber gain.

__________________
67 LeMans, 326, M20, 3.31 12 Bolt
  #52  
Old 11-08-2023, 01:14 PM
Joe-Touring Joe-Touring is offline
Senior Member
 
Join Date: Feb 2022
Location: Western WA
Posts: 123
Default

Basically, all the arms and ball joints are to allow you to dial in a modern, performance alignment. Alignment will make or break your handling performance.

Some general performance alignment specs: -0.5 to -1.5* of camber, at 5-7* of caster, and 1/8 to -1/8” of toe. I run -1.0* of camber, 6* of caster, and i think 1/8” toe in.

Too much negative camber -can- cause more tire wear, but with the mileage most guys put on their cars I wouldn’t worry about it. More important in regard to tire wear is making sure your toe stays good.

Camber directly impacts handling grip while in a turn. Generally the more the better, but tire wear can become an issue.

More caster will give you more camber while the steering wheel is turned. Will also cause the steering wheel to return to center after a turn. You want at least 6*, but 5* is much better than factory.

Toe affects stability. Toe out will make the car quicker to react to steering inputs, but will be twitchy at speed and likely to wander. Toe in is recommended for the street. Toe out is good for autocross or road racing on a tight track.

Make sure you talk to the guys at the alignment shop before you take the car in, some places will only do OEM specs. You WILL have to tell them EXACTLY what you want. Probably should write it down for em. Get a copy of the results sheet and verify before you leave that they did what you specified.

__________________
67 LeMans, 326, M20, 3.31 12 Bolt
  #53  
Old 11-08-2023, 01:19 PM
JLMounce JLMounce is offline
Ultimate Warrior
 
Join Date: Sep 2005
Location: Greeley, Colorado
Posts: 3,679
Send a message via AIM to JLMounce
Default

Quote:
Originally Posted by chiphead View Post
So explain the tall ball joint thing? When do you use tall upper, tall lower, both together, etc?

The spindles and brakes I have now are factory single-piston disc brakes. A PO did the disc brake conversion. I think the donor was a late 60s, early 70s F body. The brake hoses that fit are for a '69 firebird. Will that work with the aftermarket arms?

Will these arms accept typical coil springs or do you have to get them from SPC? The car has lowered drag-type springs that gotta go. I'd like something closer to stock ride height but have no baseline. Being able to add/subtract spacers from the front would be a killer feature.

Is it possible to replace the upper control arms with engine and headers in place? Thanks for all the input
When to use various types of tall ball joints depends to a good degree on what control arms you are putting on the vehicle. Factory arms and many of the Chinese arms have ball joint mounts in the factory location. Adding too much ball joint height can cause binding of the parts as a result, which is not something you want to have happen.

Assuming you go with a quality aftermarket suspension setup like the SPC arms, the ball joint mounts can handle the extra knuckle height. For A body cars that utilize the factory short spindle, you can use a half inch tall lower ball joint and up to a .9" tall upper ball joint. The lower ball joint does raise the pin height slightly, so you may see a lowering of the car from that part.

Running this setup would give you an effective spindle that is 1.4" taller than factory. What this does is effect the camber curve. The OE camber curve is actually reverse of what you want it to be for grip during cornering. In both bump and rebound the wheel and tire lean into the corner, instead of away from it, limiting your contact patch.

One of the main reasons for this design is that during cornering, the stresses on the actual spindle of the steering knuckle are at their highest. This forces those loading stresses onto the larger bearing and section of the spindle where there is more load capacity.

When you go to tall ball joints on the factory short spindle design and start putting the car through a lot of aggressive driving, you do have to monitor the bearing and spindle more closely as you are now loading the smaller bearing and the outer portion of the spindle that is much thinner. It is not uncommon for people that auto-x or road race regularly to need to replace bearings yearly and the spindle every couple of years.

The additional grip is worth it however if the car is actually going to be used for corner carving.

This is the reason I recommended the ATS spindle. It's 1.75" taller than factory which further corrects the camber curve. It also reduces bump steer by relocating the tie rods and uses the c7 bearing pack and hub (no spindle). This is a much more robust design that solves pretty much all of the issues related to the factory spindle. The caveat is you'll have to change your brakes as well.

__________________
-Jason
1969 Pontiac Firebird
  #54  
Old 11-08-2023, 02:31 PM
Lemans64's Avatar
Lemans64 Lemans64 is offline
Ultimate Warrior
 
Join Date: Nov 2006
Location: Vancouver Island BC Canada
Posts: 1,811
Default

Another Global West user here. ended up with 4.5* caster and -.5 camber. Car drives very nice, no wander at all. Stock rear arms that have been boxed for rear sway bar, running 7/8.
Adjustable uppers for pinion angle, Global west.

__________________
64 Lemans hardtop
4spd, buckets
  #55  
Old 11-09-2023, 09:31 AM
chiphead's Avatar
chiphead chiphead is offline
Ultimate Warrior
 
Join Date: Nov 2004
Location: Aiken, SC
Posts: 5,182
Default

So the SPC arms look really nice, but pricey. What am I giving up when going to UMI arms vs the SPC? I don't mind spending the money on the right solution, just want to be sure it fits what I'm going to do with the car.

My daily is a '15 Charger R/T road and track. It handles amazing for a 4 door sedan. If the 67 could approach that performance, I'd be really happy. I'm not building a supercar, but something to rival a modern sports sedan would be great.

Right now I'm considering the SPC vs UMI uppers/lowers. I now realize I'll have to select coil springs after I choose the ball joints and ride height i want.

So what are my spindle/brake options? Those AFX spindles are pricey. And then I've got to convert the front brakes, but to what? Could I get good results using the UMI arms and put the savings toward the spindles/brakes?

__________________
I could explain all this to the girl at the parts store, but she'd probably call the asylum.

White '67 LeMans 407/TH350/Ford 3.89... RIP
Red '67 LeMans. 407/TH400/Ford 3.25

Last edited by chiphead; 11-09-2023 at 09:45 AM.
  #56  
Old 11-09-2023, 11:14 AM
Joe-Touring Joe-Touring is offline
Senior Member
 
Join Date: Feb 2022
Location: Western WA
Posts: 123
Default

Looking at the UMI arms, the main thing you’ll be giving up is the adjustable upper arm. The UMI arms still require shims for alignment. So you might not be able to get a 100% perfect alignment with the UMI arms, all depends on your setup. I have UMI rear arms on my car, they make good stuff.

Really what you have to do is come up with a total package.

I believe the AFX spindles require you to use C5-C6 Corvette brakes. Which means you need to run at least 17” wheels. But not all 17s work lol

Another factor is ride height. I haven’t looked at spindle options in a long time, but I thinkmost aftermarket spindles have a drop built in. So if you add up total drop, with lowering springs, tall lower ball joint, spindles, you may be slammed to the ground.

Also, make sure to ask around about lowering springs, I don’t think most companies post spring rates. I think a lot are pretty soft. SPCs may be the stiffest available regular springs

__________________
67 LeMans, 326, M20, 3.31 12 Bolt
  #57  
Old 11-09-2023, 11:21 AM
JLMounce JLMounce is offline
Ultimate Warrior
 
Join Date: Sep 2005
Location: Greeley, Colorado
Posts: 3,679
Send a message via AIM to JLMounce
Default

The SPM arms allow you to run a LOT of caster because the arm itself is not only reversible, but adjustable without the use of shims. The UMI/BMR/Global West arms are good pieces but all of them use shims for alignment. With the proximity of headers and or exhaust manifolds of a Pontiac engine to the upper control arm mount, this can limit your ability to achieve more caster, which these cars need.

The SPC arms relocate the ball joints at both the upper and lower mount which gives you about 2-3* of positive caster at a neutral alignment setting. In the upper arms forward configuration you can achieve another 4* of positive caster. With the uppers in reverse installation, you can achieve caster rates of around 8* positive. I don't recommend that for a street car because you start seeing some pretty crazy movement of the wheel towards the door of the car, but the option is always there.

My alignment is currently set at just under 6* of positive caster, -1* static camber and 1/16th" toe in. No road crown adjustment.

Since it appears that there are at least some budgetary constraints here, I would recommend the SPC arms and instead of going with the ATS spindle, go with a .9" tall upper ball joint and a .5" tall lower ball joint. Along with the alignment you'll be able to carry with the SPC arms, you'll end up with suspension geometry that is about 90% of a gen 5/6 Camaro. I would go with the SPC springs which are a 1" ride height drop and make sure to get the shim kit for the lower control arms. The SPC lower has a lowered pocket. Without the shims the arms themselves provide about 2" of suspension drop. I'm fairly certain SPC makes a rear coil spring for your car. It's likely a 1" ride height drop as well. If you want to go more in the front, you may need to look for a 2" drop spring for the rear. I'd probably source those from Hotchkis.

Doing this, you retain your current spindle and can continue to use your current brakes. If, in the future you need or want more, you still have the option to move to the ATS spindle and a different front brake package.

As you can see the SPC setup is a little bit more piece meal, but I do believe it's a superior package, especially with a Pontiac engine between the frame rails. If you decide to go with UMI, my suggestion would be to buy their complete setup. Front and rear arms, their springs, sway bars etc.

One thing I want to point out on edit here. Regardless of what system you end up going with here, the cornering and lateral grip capabilities of the car are going to increase by a large enough margin, that if you don't currently have a baffled oil pan in the engine, you will need one.

__________________
-Jason
1969 Pontiac Firebird

Last edited by JLMounce; 11-09-2023 at 11:29 AM.
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 11:26 AM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 




Copyright © 2017