New setup for wheel alignment

just thinking . . . shouldn't the weight be supported at the A arm?

Agreed regarding weight on the arm to account for bump steer.  Otherwise, I think it is clever!

Alignment MUST be set with the suspension loaded. Otherwise all the settings will be wrong. Camber and Toe vary as the wheel travels through its vertical arc.

I think what you are saying is the toe in will change when the shocks are compressed, effectively lengthening the tie rods?  Perhaps I could compress the shocks with a jack to approximate ride height and support them with wood blocks, and then set the toe in.

Set the car on wood blocks under the lower shock/spring mounts. That mimics the car actually setting on its wheels. You can make the wood blocks what ever height is comfortable for you and the measuring equipment. Be sure to "jounce" the car a couple of times to help settle the suspension.

The farther outboard you support the more the car will settle. You need to set camber and toe with tires supporting the weight. As was noted before, either drive or jounce to settle suspension. I have actually seen a shop set toe after having jacked the car up to adjust camber and after it was set to 1/8" toe in I walked over and yanked down on the roll bar and toe went to 3/16" toe out.

Good input.  Thank you all.

Later on I will be setting camber and caster the traditional way with the car on ground.

I have a Track Ace laser for setting toe on the ground and will use it at a future time to correctly set the toe in.

For now I have the steering wheel mostly centered.  It was off by 180 degrees after all of the suspension work.

Obtaining the real position of the car when it is on its wheels will be very difficult, if not impossible, because stalling under the Aarms is not enough; When the suspension compresses, the wheels move apart, meaning the width of the front track increases, which is not possible if the car is on jack stands. This is why you must always move the car back and forth 2 or 3 meters when you have just lifted it so that the wheels find their correct spacing.

Why not use a system such as this one which gives good results:

https://www.ebay.com/itm/30081...FyaHZxbdGegpwOldox7N yjPtNgA5e%2FLpxt046H%2BJ02as3vjLMw9%2BL8CVlVP53qP%2BMFVBQjZYgH8knQS85GNL kS7HuRhDKuOmREnr5%2BUfaEX9te48DW%2FPAsrRORgAcPvPsOR762290ymaT1EvvHefjvIc psvT2Oq2RLVcfvIEwtvjJRNxtD8AnbkEpdfIQpMdBIbcQu%2BOUgAIR4T6z%2B%2FilnKIxSUv93 6UPoJdAjrjBIuhUDHImqwslDMEm9eS3Xfwwj3NcFGCtV8jhljHPrVKDyvWf8oFRIv4wyf%2BI81W4 xFVgUNpsbQ%3D% 3D%7Ctkp%3ABk9SR_LZ76eaZA

The measurement difference between the tape measures will varying depending on their distance apart along the bar, so you need to account for that, are you converting to degrees?

the inv Tan ( (tape 1 - tape 2) / bar lenght)

example 1/8 " for a 27" diameter tire is 1/4 degree

Hope that is right.   If not, .  .  .

@rene4406 posted:

Why not use a system such as this one which gives good results:

https://www.ebay.com/itm/30081...FyaHZxbdGegpwOldox7N yjPtNgA5e%2FLpxt046H%2BJ02as3vjLMw9%2BL8CVlVP53qP%2BMFVBQjZYgH8knQS85GNL kS7HuRhDKuOmREnr5%2BUfaEX9te48DW%2FPAsrRORgAcPvPsOR762290ymaT1EvvHefjvIc psvT2Oq2RLVcfvIEwtvjJRNxtD8AnbkEpdfIQpMdBIbcQu%2BOUgAIR4T6z%2B%2FilnKIxSUv93 6UPoJdAjrjBIuhUDHImqwslDMEm9eS3Xfwwj3NcFGCtV8jhljHPrVKDyvWf8oFRIv4wyf%2BI81W4 xFVgUNpsbQ%3D% 3D%7Ctkp%3ABk9SR_LZ76eaZA

I have the system above (Trackace laser) and will use it as suggested once the car is back on the ground.  All of these systems have their pluses and minuses.  

The Track Ace laser in the eBay listing above works great and I will use it for the final toe in setting.  It is very precise.  It can be tedious to use if things are far out of specs after a bunch of reassembly of the front end because you have to recalibrate the system after every change to the toe in setting.

This new thing from Amazon seems helpful when a bunch of suspension rework has been done.  It seems good at helping get things near specifications after significant rework, particularly for centering the steering rack and the steering wheel. It also gets the toe in setting somewhat in the ball park.  Overall it is useful to a limited extent while the car is off the ground.  It does not cost much.

@joules posted:

The measurement difference between the tape measures will varying depending on their distance apart along the bar, so you need to account for that, are you converting to degrees?

The Trackace laser measures in degrees and the final toe in setting will be within 36'+/- 4'

The car needs to be aligned as it is driven. That is why there are alignment platforms that you drive the car on to. (You can actually make one. Racers do it all of the time, usually built into their trailers)

Ironically enough, what you are measuring with the front hanging, is the "toe-change" of the front.

Racers work hard to minimize that change.  The change to toe out is generally referred to as "bump-steer".

What happens there under that condition is, under compression the tire will suddenly toe-out and the car will dart in that direction. Sometimes severely. That needs to be minimized.

The Pantera in particular is very safe in that regards even with the height spacers suddenly removed to lower the car.

The Pantera's front suspension is actually good on that, particularly used with a radial tire because the tire absorbs some of the change by flex in the sidewalls.

The "bump steer correction" in a Pantera is pretty minor and is accomplished by shimming the steering rack with spacer plates.

Starting with one of the model years, I think it was the '74, the factory automatically installed them.

The total toe in that you are looking for on a Pantera is 1/8"-3/16". That's all you need.

Stock fender Panteras don't have many issues with that. The wide fender cars do exhibit bump steer issues and will definitely show it by jiggling the steering wheel even under mild circumstances.

I don't know how to compensate for that and I think that there is no way and you just need to live with it.

Incidentally. Do not be seduced by advertising of alignment shops that offer "digital alignment equipment". Toe-in is and always has been an "approximation". It does not need accuracy to .001" or degree. That is a bunch of sales BS.

The only thing for sure is that is you don't want to get killed driving this car, BOTH the front AND REAR REQUIRE TOE-IN!

Good info Doug.  Thank you.

I will take notes on how much the toe in changes between being in the air and on the ground.  The car is a 72 but it does have bump steer shims.  The spacers on the car's stock shocks have been removed although I am swapping them out with  QA1's in a couple of weeks.

I will also check toe in on the rear wheels.  The plates might be accurate back there since there's no steering rack.  I will recheck rear toe in on the ground with the Trackace laser.

I hope it helps.

I always found that the car tracked better with 8" Campi's in front v. 7".

As it turns out, it has to do with scrub radius and judging by the results, it appears the original front suspension must have used the 8" as the design model. Not the 7".

I was searching for an answer blaming toe changes until I switched to the 8"/10" combo.

As simple as that sounds, it really stabilized the car tremendously. No need to look further.

Actually going to the 10" in the front is the wrong way to go.

I think that really is Dalara's contribution initially? No one ever claimed he was a dummy. Even Ford's changes couldn't screw that up.

You guys... I used fishing line to set-up every race car I serviced including GT 40's Formula, Indy, etc.

Make sure car not bent/broken. Measure wheelbases side to side.

First is to set your corner weights and ride heights. Disconnect sway bars, one end loose on front and rear bars. Use a laser or water/clear tubing and floor tiles to get all four scales at same elevation.  Get your front/rear, side to side bias and ride heights close.

Next. Jacks under front arms and set your camber. Use jacks to get the tires off ground to swing lock to lock with camber gauge. Get your camber gains. Compare to tire wear after thrashing. Shoe polish marks on sidewall gets air pressure right. If not, you need camber change.

Use 4 heavy jack stands (we fabbed stands or a bar to look important) and fishing line. Make a "U" with fishing line wrapped around jacks that car fits in. String height near center line of wheels. Check to make the "U" is square by matching diagonals. Metal yardsticks from string to edge of rims. Toe settings for front and rear. Roll car in and out of "U" to settle changes.

Insert driver and spend weekend screwing it up.