Alignment Issues

gMAG · Aug 24, 2016

dhutton said:
Curious why you went from drop springs to drop spindles.

Don

I found that the firmness of the drop springs combined with a frame made rigid with welded frame connectors, made for a ride that could instantly "hop" over minor pavement irregularities under acceleration. This could be unsettling and dangerous at certain rates of acceleration and speed.
There was a benefit to adding new small-block stock springs. The spring rate balance between front and rear now is even, and the car now glides over uneven pavement, though the steering issues remain unsolved.
I have Hotchkiss 1 1/2" lowering in the rear.

gMAG · Aug 24, 2016

davidpozzi said:
With positive camber on a wide tire, it shifts the tire contact patch outward away from where it should be. This can make each bump in the road pull the car to that side.

David, this is exactly what is happening. I noticed that Guldstrand recommended 0 deg camber when using 2" drop spindles. Don't know if this is related to your specific camber comment, ^^ above.

davidpozzi said:
Did you bolt the steering arm to the lowest pair of holes? the brakes bolt to the upper holes, the steering arm to the lower so it stays in the proper height relative to the lower ball joint.

I'll have to verify this.

davidpozzi said:
I would also take up the lash in the steering box.

This has been done. I have an IROC box, and the alignment guy seemed to think that the faster ratio of this box was contributing to the steering issue. The steering issue happens on its' own...without moving the wheel.

Thanks, Glenn

davidpozzi · Aug 24, 2016

First gen Camaros have toe out in bump, stock. Adding a tall spindle makes this worse. Increasing positive caster to +5 to +7 degrees helps tilt the spindle down in the rear, lowering the outer tie rod ends & reducing bump steer. The only way to really know how much you have is to measure it. Bump steer can be measured by opening the hood, & stacking weight on the radiator core support. A hefty friend on each fender near the core support should push the front down a couple of inches and a toe reading can be taken (keep off the header panel, it will dent). Usually the wheels toe out when the front suspension is compressed. This is felt in driving when you brake hard, the car wants to zig zag left & right. Any change in ride height will affect your toe setting. So if the car is aligned to 1/8" toe in without driver, and you place two people in the car and drive down the road, the car may have zero to some toe out, with even more when a dip is hit or you brake.

When cornering, you steer towards an apex point, the chassis rolls, and steers itself away from the apex. This requires corrections to steering input, - usually the driver has to apply more steering lock to keep the car on it's intended path. The inside suspension lifts causing toe-in, the outside suspension dives, - causing toe-out.

You need to set caster at 5 degrees positive. If autocrossing, set to 7 deg positive if possible. I would add .5 deg more caster to the right front to help compensate for road crown. This helps the car run straight.

gMAG · Aug 25, 2016

davidpozzi said:
First gen Camaros have toe out in bump, stock. Usually the wheels toe out when the front suspension is compressed. This is felt in driving when you brake hard, the car wants to zig zag left & right. Any change in ride height will affect your toe setting. So if the car is aligned to 1/8" toe in without driver, and you place two people in the car and drive down the road, the car may have zero to some toe out, with even more when a dip is hit or you brake.

Thanks for this info. It is all new to me. I have 150lbs less over the front (aluminum LS1), so would this have any less of an effect to toe out?
The lighter weight up front was another reason why the relatively firmer lowering springs were ditched. I had forgotten about that.

davidpozzi said:
You need to set caster at 5 degrees positive. If autocrossing, set to 7 deg positive if possible. I would add .5 deg more caster to the right front to help compensate for road crown. This helps the car run straight.

Today, I spoke with alignment person, to verify that he could realize +5 deg caster. The car goes back for alignment on Friday. Now that the weather has cooled, I'm excited about getting her back on the road...safely!
Do you recommend + camber, as well?

camarodriver67 · Aug 25, 2016

Global West recommends drivers side 5 degrees positive caster, 0-1/2 negative camber, and 3/32 toe in. Passenger side 5 1/2 degrees positive caster, 0-1/2 degree camber, and 3/32 camber. This is for tubular upper control arms. They do not offer any change for 2" drop spindles or lower tubular control arms.

davidpozzi · Aug 26, 2016

I'd use a half degree neg camber, 5 deg positive caster driver's side, 5.5 deg passenger side. Set a good amount of toe-in like 3/16" total. While it's on the rack and he is setting toe, have him pull the front down 2" and read toe. See how much it toes out. My 67 Camaro with Guldstrand mod toed out something like 1/2" at 1" compression! At 3" compression, it had an inch toe out.

Tall drop spindles generate more neg camber so you don't need to set a lot of static neg camber. If you were autocrossing a lot I'd go to 1 deg or 1.5 deg negative camber. If you had stock spindles, no Guldstrand mod, and were autocrossing, I'd set -2 deg to -2.5. I'd also increase positive caster to +7 deg for a serious autocross car. Sometimes you can't get that much.

If he doesn't have a way to pull it down, stack weight on the core support or have a guy sit on each fender in line with the core support. If it still has toe-out in compression, you can add more positive caster, -up to 7 deg driver's side, 7.5 passenger side to further reduce toe out in bump. Adding positive caster will move the wheel slightly rearward, this reduces tire clearance to the rear splash panel at full lock. Sometimes the panel needs to be bumped in with a hammer. The other alternative is to loosen the subframe bolts, (6) and the bumper braces at the frame and slide the sub forward slightly. You have to support the rear frame rails with a jack when you do this. Watch distributor cap to firewall clearance. If you manage to get toe out in bump under control, then you can reduce total toe in to 1/8" or 1/16".

gMAG · Aug 26, 2016

Thanks, Dave and all. I'm watching a line of thunderstorms (don't drive the car in the rain!), and getting ready to drop off car for alignment.

Glenn

gMAG · Aug 28, 2016

Went for alignment today.
The new specs are Caster L/R > +5.2 and +5.7. Camber +.2 and 0.0. Toe + .19 both sides.
The steering is somewhat better...no longer dangerous, but still waves back and forth, and any acceleration and any breeze causes the car to drift.
All steering, suspension, bolts/ perches, etc are tight.
To address the "tall spindle" comments, I have the stock height.
I'm not sure where to go from here. There have been at least a hundred different projects on this car, and I haven't given up on any of them. This may be the first time that I do.

dhutton · Aug 28, 2016

gMAG said:
Went for alignment today.
The new specs are Caster L/R > +5.2 and +5.7. Camber +.2 and 0.0. Toe + .19 both sides.
The steering is somewhat better...no longer dangerous, but still waves back and forth, and any acceleration and any breeze causes the car to drift.
All steering, suspension, bolts/ perches, etc are tight.
To address the "tall spindle" comments, I have the stock height.
I'm not sure where to go from here. There have been at least a hundred different projects on this car, and I haven't given up on any of them. This may be the first time that I do.

Why do you still have positive camber? I think negative camber has been widely recommended.

Don

gMAG · Aug 28, 2016

dhutton said:
Why do you still have positive camber? I think negative camber has been widely recommended.

Don

This attempt, neg camber was tried first with similar result. There is something else going on.
I did find the front leaf spring perch bolts not torqued to spec. No result was realized after torqueing.

Click to expand...

allanjs · Aug 28, 2016

gMAG said:
Went for alignment today.
The new specs are Caster L/R > +5.2 and +5.7. Camber +.2 and 0.0. Toe + .19 both sides.
The steering is somewhat better...no longer dangerous, but still waves back and forth, and any acceleration and any breeze causes the car to drift.
All steering, suspension, bolts/ perches, etc are tight.
To address the "tall spindle" comments, I have the stock height.
I'm not sure where to go from here. There have been at least a hundred different projects on this car, and I haven't given up on any of them. This may be the first time that I do.

Glenn, It sounds to me as though you may have a tracking issue. Did the alignment shop check it ? Also tires or under inflation can cause wandering. The steering gear may need to be adjusted also.

gMAG · Aug 31, 2016

Got the car back today after verifying align specs. Camber was changed to -.5 deg. Caster was able to be increased to +5.4 & +5.9. Toe = +.19 deg.
While the car now goes straight, the turn angles are too aggressive, and the steering still requires too much attention & adjustment. Every dip in the road causes arcing.
The former lowering springs/IROC box/stock steering did a better job overall.
For now, the car is usable, and a "little" acceleration is safe!

davidpozzi · Aug 31, 2016

Can you post a couple of photos of your spindles, where the steering arms bolt on? Are your outer tie rod ends lower than the lower ball joint?

gMAG · Aug 31, 2016

davidpozzi said:
Can you post a couple of photos of your spindles, where the steering arms bolt on? Are your outer tie rod ends lower than the lower ball joint?

Will do, later today.

gMAG · Aug 31, 2016

Driver's>>

davidpozzi · Sep 4, 2016

That looks correct. I dont' see any issues that would cause problems. Are your rear tires brand new? I've seen terrible directional problems with half worn fronts and brand new rears.

gMAG · Sep 10, 2016

Thanks Dave, Don, & all. Some thoughts after driving for a few days....the IROC box does emphasize irregularities in the road surface (and, vice-versa). I am reverting to the standard box for a comparison. The new springs have not settled...are still two inches too tall, giving cross-winds greater influence at the side fenders, and in general. The previous lowering springs took several months to settle almost 3 inches, leaving the fender a perfect 3/4" above the tire and improving aerodynamics.

Glenn

BMR Suspension · Sep 15, 2016

What are Tire conditions & age? Your car could be "Tram Lining"

gMAG · Sep 19, 2016

BMR Suspension said:
What are Tire conditions & age? Your car could be "Tram Lining"

No unusual tire wear/5 years old, 15k miles/car ran fine 2 months ago.
Here is something I spotted today. Upper a arm forward arms are rubbing against fender wells.

davidpozzi · Sep 19, 2016

gMAG said:
Thanks for this info. It is all new to me. I have 150lbs less over the front (aluminum LS1), so would this have any less of an effect to toe out?
The lighter weight up front was another reason why the relatively firmer lowering springs were ditched. I had forgotten about that.

I don't know how much of the Hotchkis TVS system you have. The sway bars dont' look like Hotchkis. If you went back to stock front coils, then the front is going to move a lot more (twice as much) and your spindles increased bump steer a lot. So the result is going to be a better ride, but increased bump steer/directional issues. Do you have a rear anti-roll bar on the car? If so, I'd disconnect one rear end link and test drive the car.

What do you have for shocks?

check your front leaf spring perch bolts. I've seen them slip and the brackets crack due to being installed a bit too loose and moving. Two of the three bolts are slotted in the bracket, so only one bolt holds front to rear positively. Any movement of the rear axle F/R will be felt/unstable.

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