Next week I'm getting my alignment following my suspension rebuild (pre-L, 3518). The alignment shop does a lot of high-end sports cars but has never worked on a Pantera. I think I have the correct specs but the shop asked if there were any special techniques, tools or shims required. So what is the collective wisdom here? I have four of those C-shaped shims (three thick and one thin) but I have no clue how many might be needed. Help guys.
Original Post
Are you sure you're taking your Pantera to the best alignment shop? You should ask around, to see which shop other Pantera owners in Northern California have used. I've heard excellent things about Roger Krause Racing in Castro Valley, from other Pantera owners.
Did you rebuild the suspension yourself? If so, there are things you can do to get the alignment into the ball park. An inexpensive camber level helps you to match the settings on front to front and then back to back. I also used cheap laser levels (adapted to fit the wheels) to set toe on both the front and rear. I think they sell a string system that works the same way. I once did all of this on a Porsche 911 and took it to a specialist for final alignment and four corner balancing. He said it was very near correct. I did the same process on my previous Pantera and it drove very nicely. The down side to this is that it takes a lot of time.
I do my own alignments (mostly focused on the race car), it really isn't that hard if you set yourself up with the right tools and have some time.

The Pantera is particularly finicky in the rear as an adjustable rear camber bar in the engine compartment can alter rear camber. The toe adjustment (by shims) is very dependent on having solid chassis rails with little flex.

Personally I would not go to the extent of doing a 4 wheel alignment without ride height setting and corner weighting included.

Julian
This is a good local shop, BR Racing in Los Gatos. Castro Valley is too far away. And I know it sounds like heresy but I'm not going to do a DIY alignment. The suspension was rebuilt by a local Ferrari expert. I've read all the online stuff and I have the specs figured out. I'm really looking for basic info on shims, tools and any precautions. For example, I don't want to get to the shop and find that they need shims for camber and none are available. I appreciate all the input.
Not sure where I got this....

The recommended alignment settings for the Pantera suspension listed in the de Tomaso Pantera Technical Service Bulletin Number 5, Article Number 33 have + or - specs and can be adjusted within the spec for your driving requirements.

Factory recommended alignment settings:

Front Settings
Camber, 1/8 degrees neg to 1/8 degrees pos.
Caster, 2-3/4 degrees pos.
Toe-in, 1/8"

Back Settings
Camber, 3/8 degrees neg to 5/8 degrees neg
Toe-in 1/8" to 3/16"


From: Mike Thomas
Pres., Panteras Northwest
Yellow '74 #6328

Here are the stock specs as I received them a while back from one of our folks. Just had 6328 reset and it drives wonderfully.

Front Camber: -1/8 deg
Front Caster: +2.7 deg
Front Toe-in: 1/8"

Rear Camber: -3/8 to -5/8 deg
Rear Toe-in: 1/8" to 3/16"

Recommend as much front caster as you can get though and if you like to corner hard, -1/2 degree negative camber in the front would be advised.
quote:
Originally posted by Robbie:
I'm really looking for basic info on shims, tools and any precautions. For example, I don't want to get to the shop and find that they need shims for camber and none are available. I appreciate all the input.


Did your Ferrari guy know to use offset bushings for improved caster, camber locks etc.? Rubber or poly bushings? Did he do all the sway bar bushings?

If he rebuilt it stock, then just go with the stock specs on alignment. You may need shims for the rear toe/camber, but if he put it back together the way it came apart it shouldn't be far off.
No off-set bushings, no camber lock, poly bushings, new sway bar bushings (and a bunch of other stuff). My only concern about the 1972 stock alignment set up is that it is based on bias ply tires. I'm not sure if radial tires make the specs different in 2018.
Regarding shims for the alignment, Pantera does not have special needs. Just about any of the shims from the alignment shop's assortment should work just fine.

There are threads saying that Pantera needs more front caster. This would require specialized bushings in the upper from a-arms. Since you don't have them (nor do I) just ask them to get the most caster they can produce and your car will drive nicely.
quote:
Originally posted by Robbie:
the 1972 stock alignment set up is that it is based on bias ply tires. I'm not sure if radial tires make the specs different in 2018.


R, the 1971 and 1972 Panteras were equipped with radial tires from the factory. Anyway, my Pantera has radial tires. It is aligned to the settings the cowboy and everyone else has recommended. It handles great.
Only in the US do people seem to quote toe by inch measurements (rather than degrees, minutes & seconds), the problem with inch is it is a difference between the leading and trailing edge of the tire, so different wheel/tire combinations (diameters) will produce a different result.
If anyone has a hidden passion for math I recommend you go online and read all the approaches to converting alignment specs in inches (or fractions thereof) to degrees, minutes and seconds. It seems that most modern alignment equipment has shunned inches and is all about angular units. But there are a lot of approaches .. mostly academic .. to making the conversion. Seems more suited to orbital mechanics than Pantera mechanics. Eeker
Watch you rear negative camber. The factory setting are way off and will wipe the inside tread in 1000 miles. Remember every bump you hit the car goes negative. You butt in the seat will make it move negative so depending upon your tire width size and what the intended use is (street or track---tire type and compound) camber setting will change. I run most cars 0 to + on the camber depending on the drivers weight and again, tire size.
Yes and sometimes you can get the neg issue corrected without longer upper arms but you need to pull the non slotted washers off the forged lower A-arm mounts--that helps. If it's still negative, longer upper arms will be needed. Been extending them for many years now because twisting the car apart with the adjustable camber bar between the shocks just did not work for me.

Was answering and post an it vanished like my money when the wife goes shopping.
Thanks Kirk,

I was editing my message and lost my reply in this thread.

It looks like the extended upper rear a-arm can help to solve the problem with too much negative rear camber when the car is lowered. Thus our goal is to have zero or slightly positive rear camber when the car weighted. This is to avoid excessive inner tire wear. Am I correct?

Thanks, Steve
I have had my car for 25years and I drive my car.
The stock alignment on the front is ok if you are a purest with all stock front end brakes, bushings, shocks, rack etc. The problem is stock front suspensions have no or very little caster. Caster is what allows the car to go straight, the more caster the better the Pantera likes it, with little or stock caster the car is darty, it wants to react to quickly to steering wheel impute,, it's the difference two hands and white knuckles at 80 and one hand tuning the stereo at 80. The shims you have are for the upper ball joint you want to move the upper ball joint as far to the rear and the lower as far as possible to the front this will give you positive caster. to achieve more positive caster? change to staggered bushings, this is easy and effective it moves the entire upper arm back and the lower arm forward, now you have caster and a far more stable and drivable car. As far as who to take your car to, in the attached picture you will see upper right hand corner that the Pantera is included in modern alignment computers.

Attachments

Photos (1)
quote:
Originally posted by SteveBuchanan:

'It looks like the extended upper rear a-arm can help to solve the problem with too much negative rear camber when the car is lowered. Thus our goal is to have zero or slightly positive rear camber when the car weighted. This is to avoid excessive inner tire wear. Am I correct?'

Thanks, Steve


Steve, your goal above is correct. But the problem, typical of a powerful 45-year-old spot-welded sports car, is that various parts of the rear monococque are gradually collapsing; spot welds are breaking or distorting and that badly affects the rear wheel alignment, whether or not the car is lowered. So adding extended upper rear a-arms does not correct the problem but simply corrects existing wheel misalignent, which will continue to change. There are two MORE possibilities for addressing the problem.

1)- by adding an adjustable bay-brace-bar with an extended nose section- such as Hall's straight steel bar to replace the dog-led stock bar with NO adjustment, camber alignment correction can be gradually added in while better supporting the whole rear suspension. Basically, you jack up both rear wheels and crank in 'some-but-not-all' needed pre-load with the bar's center adjuster, lower the car, check camber and drive it that way for a few days, then repeat until your rear camber is tolerable- typically less than -1 degree.
WARNING: trying to add in ALL the needed correction at once may buckle the rear fenders or quarter panels. Be patient and let the sheet metal/chassis relax in between adding correction stresses.
2)- The real fix is to first do the above, then seam-weld the entire rear of the car to supplement the original spot-welds. This better supports the camber correction from the bay-brace preload and markedly improves the Pantera's handling, according to those who have done the full correction. But for many Panteras, doing only Part 1 seems to satisfy them. A third possibility is to have a professional shop correct your sagging subframe. Wilkinson has a frame jig and the spec's, and has done this for some Panteras.

Note that Dallara cautioned DeTomaso on this very thing in 1970 before the car was released to the public, but DeTomaso poo-pooed his fears, famously replying, "Don't worry- streets in the U.S. are as smooth as a baby's bottom!" Don't know what part of the U.S. road & highway system A. DeTomaso was referring to....
What BW says is absolutely true.

The design of the structure in the rear did not have much consideration for longevity to it.

It was a "performance" design from the era by a Formula 1 race car designer.

In addition to a little bracing up in the rear another way of adding needed adjustability would be to use the height adjustable coil overs currently available.
The alignment deed is done. The results are amazing. It demonstrates how poorly a car rides and handles when the alignment is out of whack. As odd as this sounds, I am going to be driving 3518 much more because it's a pleasure not a chore (hey that rhymes). The work was not cheap and it took 4+ hours but well worth it. Check that off my list.
I've been thinking about posting my specs .. however, this is a tough audience. I'm sure I'll be the subject of many ".. you should have .." comments. But what the hell. Tires: Goodrich TA ,, 205/60-15 and 245/60-15 inflated to 31 and 34 psi respectively.

Front

Caster .. 3.6 and 3.7 degrees, all shims to the front if the upper ball joint. Got all we could.

Camber .. -0.4 degrees

Toe-in .. -0.21 degrees total

Rear

Camber .. -1.6 degrees. Here comes the comments. All of the shims were removed and we couldn't get less camber .. targeted for -1 degree.

Toe-in .. -0.25 degrees total

Per one of my earlier posts, converting from fractions of an inch to degrees is higher math. We actually used 1988 Ferrari Testarosa specs as a reference since it is similar to the Pantera in size, weight, suspension, etc. Comments from this learned group were carefully factored into the mix.

So take your best shot .. it handles well. I'm not a track or autocross guy. A few twisty roads now and then works for me. And this setup feels good .. planted .. straight. Be gentle
one dimension not stated would be ride height that would effect the amount of rear camber. I am not sure exactly where it should be taken but to me a better indication of ride height as it effects alignment would be arm angles.

some of the notes I have dug up on frame dimensions might help determine the reason.

Attachments

Photos (1)
My observation of the rear lower A-arms is that they were horizontal. I had new Koni gas shock/spring packages from Pantera Performance and I asked them to set the ride height to their best judgment based on my driving requirements. We didn't measure the ride height but visually the height is lower than stock based on tire-to-opening space. I couldn't find what the best height is and where the measurement is taken,
I would think the ride height is most conveniently stated from the bottom of the frame rails to the first horizontal surface, the ground or surface of the alignment machine platform?

Thank you for posting your results.

I think that by changing the compression rates of the springs and shocks from stock that is going to change the specs necessary on the alignment?

I need to go through this soon so this is helpful to me as to where at least to start.
Hi Robbie,
Many thanks,
Cheers, Tim

quote:
Originally posted by Robbie:
I've been thinking about posting my specs .. however, this is a tough audience. I'm sure I'll be the subject of many ".. you should have .." comments. But what the hell. Tires: Goodrich TA ,, 205/60-15 and 245/60-15 inflated to 31 and 34 psi respectively.

Front

Caster .. 3.6 and 3.7 degrees, all shims to the front if the upper ball joint. Got all we could.

Camber .. -0.4 degrees

Toe-in .. -0.21 degrees total

Rear

Camber .. -1.6 degrees. Here comes the comments. All of the shims were removed and we couldn't get less camber .. targeted for -1 degree.

Toe-in .. -0.25 degrees total

Per one of my earlier posts, converting from fractions of an inch to degrees is higher math. We actually used 1988 Ferrari Testarosa specs as a reference since it is similar to the Pantera in size, weight, suspension, etc. Comments from this learned group were carefully factored into the mix.

So take your best shot .. it handles well. I'm not a track or autocross guy. A few twisty roads now and then works for me. And this setup feels good .. planted .. straight. Be gentle
Tim, FWIW- if the front feels good with that caster, fine. Otherwise, offset upper a-arm bushings (poly) can add up to 2 more degrees, adjustable to 'around 4 degrees' by adding shims back in. Steering effort may go up slightly with more front caster.

The rear camber is further correctable (to zero or very close) with an adjustable rear camber bar that has extended nose sections on each end for bracing. In this design, the bar is not applying all its force to two thin sheet metal tabs. See Hall's straight steel camber bar design, or add nose sections to an aluminum adjustable bar.

Add Reply

Likes (0)
Post
×
×
×
×