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I need new set of front tires and I know that its time for an alignment so I decide that this is the week to knock it out.

The setup: 225/50r16 fronts and 335/35r17 rears with adjustable shocks, upper ball joint shimmed and a big block. The tires are very sticky and most of the road in my neighborhood are very twisty. I am not a real wild driver but I do get after it time to time and I plan on autocrossing it once or twice a year (Good Guys).

Front: My understanding is to set the Caster as pos as you can up to 5 Degrees (I think I can get up to 3 1/2). Camber neg 1/2 degree (spec is only up to -1/8) and toe-in ?? (I have seen 1/8 and 1/16 (spec is 1/8))

Rear: rear spec is Camber neg 3/8 to neg 5/8 and tow in 1/8 to 3/16 but I have seen people mention as little as neg 1/4 and zero toe for wide tires.

My car goes in on Thursday and any input would be helpful (ok most input will be helpful) Big Grin

Thanks
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the chart below may provide some perspective

(the numbering & lettering became a little fuzzy when I compressed the file, apologies)

Food for thought: Increasing positive front caster equates to the front tires "leaning" more into a corner when the steering wheel is turned, this quickens steering response and reduces understeer. Understeer can also be improved by increasing negative camber, but at the expense of increased tire wear because the tires are always leaning inward, even when the car is not cornering. Tire wear caused by negative camber can be cancelled out by "toe-out" but that in itself has draw backs (destabilizing), which is why "street cars", even those with lots of negative camber, are usually spec'd with just a bit of toe-in. The best way to go, in my opinion, is to modify the upper front control arms and dial in about 5 or 6 degrees of positive front caster. If you have that, you don't need a bunch of negative front camber.

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8pack;
The latest I have regarding alignment was published in a TSB, August 1974 as follows:

Toe In Front 3/8" Toe In Rear 1/8'- 3/16"
Caster Front 2 3/4 degree Pos, Rear-nothing indicated
Camber Front 1/8Neg to 1/8Pos camber, Rear 3/8Neg to 5/8Pos

The service manual also states to have 88 lbs on each seat, 66 lbs in each foot well and a half tank of gas. (I guess stop by your local Gold's gym?)
It appears George's previous post is more detailed regarding specific models.
Original alignment specs predicate original tire profiles. If you have wider flat tires this can effect how you set up some things as well as if you set them up for a track.

Assuming you are not setting them up for a track:

Toe in can depend some on how worn your front end is. The purpose of toe in in general is not to have any toe out. As things flex, your front will try to spread. If you have slop, you need more toe in to stop the spread. If everything is tight, you can go with a tighter toe in (less toe in).

As far as camber, if you have wide and flat tires I would really try to limit the amount of camber.

Without power steering I think 4 degrees would be on the high end. The more caster, the more the steering wheel will fight you in the turns.

Once you have a starting point you need to watch tire wear based on how you drive.
My advice is to find an alignment shop that has experience with sports cars or even racing cars. Perhaps it's worth the drive to take it to Roger Krause Racing in Castro Valley. As Comp 2 mentioned, the OEM specs are mostly meaningless unless you're running OEM tire sizes.

Just for fun, here are the alignment specs for a Ferrari F40; which has similar suspension, weight distribution and 245/335 section width tires.

Front: Camber: -1°10" to -1°30"
Toe-in: 1.5mm to 2.5mm
Caster: 5°10" to 5°20"

Rear: Camber: -1°0" to -1°20"
Toe-in 2.5mm to 3.5mm
quote:
Who are you taking your car to?

Custom Alignment in Mountain View. They came highly recommended by the PCNC track crowd as having lots of Pantera experience, as well as being very well known in the Shelby club and Porsche club for setting up their track cars.

Custom Alignment Balance and Brakes
2599 Wyandotte St
Mountain View, CA 94043
(650) 961-5311
https://www.google.com/#q=cust...gnment+mountain+view

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