Since wearing out new tires in a short period I started this topic . https://www.fiero.nl/forum/Forum2/HTML/141316.html
I am thinking of putting General G Max AS 05 tires on. 235/45/R17 on the rears and 215/45/R17 on the front. I can not remember the offsets on the wheels but I can find out.
It also has a 3800 SC in it so it is a bit heavier in the back.
I need an alignment and I there seems to be some controversy on the specs.
Here are the specs from the tire shop.

Any comment would be greatly appreciated. I just want to do it right.
Also, does wheel offset affect the alignment if at all and should I be checking out things on the suspension?

Thanks, Car54

[This message has been edited by car54 (edited 09-20-2018).]

One of our club members has a new Coats alignment machine. These are the numbers in his machine.

Thanks fierofool. Those specs seem to be very close to what the shop stated.

Note the jouncing requirement for the 88 every time the wheels are lifted off the rack. That's where many techs screw up.

Since your car had a severe tire wear issue, the first thing I would do is check check every suspension bolt/nut and verify it is at the proper torque. Look around at the bolt heads to see if there are signs of a bolt sliding or being moved from where it once was. It isn't uncommon for people to add larger brakes or more power and be able to slide a snug but not properly torqued bolted connections of the suspension due to the increased load, which will throw off the alignment. If it shifted in that direction, tighten the bolts there (this is where they want to be with your driving style and are less likely to shift again).

Then have the alignment checked for the current setting. This should show you which corner of the car has the issue, what type it is (Caster, Camber, Toe), then you can start working to find the culprit (or confirm what you found in your earlier inspection).

Once you go poly bushings (and/or rod end lateral links in the rear), then bushing deflection becomes less, so you can run closer to zero toe in the front and rear.

For my 88, I do all my own alignments using the string method with the car sitting on blocks.
I target to the tow to be 1/32" to zero toe in. camber front/rear is 0.7 degrees negative (top of tire tucked in, bottom kicked out), and front caster set to the maximum I can get on both sides, with both sides set within 0.1 degrees. Normally this is about 6-7 degrees. Using this setup I have over 46K miles on a wide set of extreme summer tires with a 200 wear rating and the engine has 382 whp, so I can spin the rears w/o issue, but normally just get them grip.

[This message has been edited by fieroguru (edited 09-21-2018).]

Fieroguru

I use to do a string alignment on my Rormula Ford race car. What do you use to center your strings from ?
How do you measure your caster? I believe that on my race car I would have to turn the wheels 20 degrees each way and measure the camber each direction and then do some math.
Do you measure your toe from the tire itself?
Is camber measured with a digital level?
What is the purpose of the blocks?

Thanks, car54

I have 2 pieces of conduit with holes drilled on the end at the exact same dimension.
I set the conduit on the jack stands with some 2x4x1/4" wall steel tube in the center. This holds them down and keeps them from moving. Then fishing line is ran through the holes from end to end. From there I measure off the line to the center caps on the wheels and nudge the conduit side to side until I get the same measurement side to side.

If I am going to be adjusting camber or caster, I remove the wheels, rest the car on the rotors on the blocks. I jounce the car several times, but now the suspension is fully loaded and w/o the wheels I have plenty of room to reach every adjustment bolt w/o needing to jack the car back up. In the rear, I use a harbor freight digital angle finder to set the camber (prior to lifting the car onto the blocks, I run a bar over the blocks and use some sheet metal to shim the blocks so the digital angle finder reads 0.0).

In the front, I have the factory tool for setting camber/caster. I have 2 of the angle finders, so one goes on the rotor for camber, one rests on top of the tierod mounting surface. This surface is perpendicular to the ball joint centerlines. I use the factory upper a-arm cross shaft tool to position the cross shaft while fully loaded while watching the camber and caster digital displays. Camber is kept at 0.7 degees, while maximizing the caster with the available adjustments). Then I do the other side. If I can't reach the same caster/camber as the other side, then I max this side out, then return to the other and make it match.

With the camber and caster dialed in, I recheck the placement of the strings and reposition the conduit if needed.

Then I adjust in the toe. I have some 3/4" square tubing that is 24" long with tabs welded to the end with a notch for the tape measure. These bolt to the bottom of the rotors and the offset tabs allow the tape measure to run under the chassis. The weight of the tape measure keeps in in place and I adjust the toe so there is less than 1/32" toe in front and rear.

When I am just checking the front/rear toe, I keep the wheels on, set the tires on the blocks, jounce, setup the strings using the center caps, then I check the toe with a tape measure from the string to the wheel lip.

I check the toe every summer before my first large trip. Caster and camber are checked anything I change out a part or think there is an issue.

Fieroguru,
I did a quick string test . I have .140 toe in at the string level of the wheel. The wheel is 18.25 inches at the string level and it calcs out to be .45 degrees which is 3 times the standard of .150 degrees. Here is a calculator that I used.
https://robrobinette.com/Co...eDegreesToInches.htm

Next I will check all the components out.

Thanks, car54

[This message has been edited by car54 (edited 09-22-2018).]