Do I need an alignment shop....

[ischmitz]

...to tell me the car (rear suspension) is not straight?

here is what I did after installing new tires, new rims, new turbo tie rods, steering rack spacers, adjustable spring plates and new torsion bars all around:

1. After getting everything on the car I did an eyeball rideheight adjustment and then put the car on the corner balancing scales to set the diagonal weight distribution to be within 10 pounds of each other with 60kg of weight in the drivers seat. Well, my car is a little heavier in the left.

2. I centererd the steering rack and put the steering wheel on straigt.

3. I took a straight edge with a laser mounted to it to the front tires and got the toe adjusted to be about 1/4 degrees in as seen in the before picture. Both wheels toe in exactly the same amount. Of course the tires where on the ground.

The fist test drive with the steering wheel centered was essentially a right turn. Bummer.

4. I took the straight edge/laser method to the rear wheels and found the BEFORE status. I had to max the left rear wheel toe setting out to remove exessive toe-out.

5. On the right rear wheel I had to max out the setting THE OTHER way to get rid of exessive toe-in.

When you look at the before and after pictures I have gotten from a NASCAR setup to pretty decent straight line performance. I am still bothered that the toe settings are maxed out the oposite ways in the rear. Something is wrong here.

I also had to dial in all the negative camber in the back I could get to prevent rubbing in the left rear. It seems like the left rear wheel sticks out further than the right rear wheel.

Now do I need an alignment shop to tell me what I suspect; the PO must have slammed sideways into some curb at some point and bent a banana arm in the process. Maybe more. I will have it put on a jig tomorrow and see what the experts say. Still I might be in need of a rear aluminum trailing arm, eh?



Any thoughts?
Ingo

[dad911]

What is your total rear toe? You should never have toe-out in the rear. Could one of the rear bushings be bad/worn?

[Speedster94]

hallo Ingo
Did you lift the Car ß Then drive it for 20 miles before you set it up. And dont lift it before .
harald

[surflvr911sc]

Somebody please correct me if I have this backwards. I believe that as you dial in negative camber the wheels will toe out. Then when you toe in the wheels will move toward positive camber. Just stating so we all know what’s happening while adjustments are made.

Are you driving the car in between adjustment or do you have the tires on sliding plates? The tires on a concrete surface will resist the changes you make so you will be over adjusting to get it where you want it.

Bushings? I know you don’t want to but…

Assuming everything was right during the adjustment process, i.e. perfectly level concrete (rare), no loads other than the cars weight on the wheels, bushings are sound, etc., you still need to look at the method of measurement. Measuring in the garage gets me close enough to drive the alignment shop but unless you have alignment measuring tools and a perfect floor you are not close enough for real driving. No matter how many times I measure and adjust it amazes me how far from perfect I get.

I think that the best way to know for sure would be to put the car on an alignment rack and see what happens, and then you will know for sure.

[ischmitz]

All: I lifted the car for doing the toe-in adjustments to at the rears. And yes I drove it after every adjustment making sure the suspension settled. The neighbors got pissed because it was almost midnight by the time I was done and I live on a steep road.....

I will take it into an alignment shop tomorrow that has Porsche and race car experience. They did MikeZ's car and seem to know what they are talking about.

Still, my laser method gives very accurate readings. Over 6m (20feet) distance I can measure a 1/4 inch difference of the laser spot (or better) repeatably. That is equivalent to about 0.06 or 1/16 degrees resolution.

If the measurements on their jig tomorrow are way out of the ordinary I will get new bushings (jaja Ryan, I hear ya) and bite the bullet installing them. What's a good time for you Ryan to maybe give me a hand ?

dad911 I don't have the exact numbers for the toe-in of my rears with me here. What I remember is that the right rear is almost at zero toe (the laser hits the front wheel edge). The left rear is toed out by about 0.2 degrees. (Can't toe it in more)

Would you go after the banana arm bushings first or the spring plate bushings or all of them? When I put in the rear spring plates its bushings looked to be in O.K. to good shape. I never looked at the banana arm bushings so far.

Ingo

[addictionMS]

read this

http://www.smartracingproducts.com/ follow the products page, then the alingment page and read the instrctions for the smart strings, should give you some good ideas on what you need to do.

[surflvr911sc]

I look forward to hearing how it turns out on the rack! Good luck, hopefully it's bushings.

Originally posted by ischmitz
If the measurements on their jig tomorrow are way out of the ordinary I will get new bushings (jaja Ryan, I hear ya) and bite the bullet installing them. What's a good time for you Ryan to maybe give me a hand ?

I don't have too many free days in the next couple weeks but I'm sure we can work something out. It might give me a good excuse to ditch work.

I don't have the exact numbers for the toe-in of my rears with me here. What I remember is that the right rear is almost at zero toe (the laser hits the front wheel edge). The left rear is toed out by about 0.2 degrees. (Can't toe it in more)

Are your toe measurements only going off of where the laser hits the front tires? I would think that there would have to be a lot of planets aligned (no pun intended) for that to be truly accurate. And if you are setting the laser against the rear tire then it would be even worse.

Would you go after the banana arm bushings first or the spring plate bushings or all of them? When I put in the rear spring plates its bushings looked to be in O.K. to good shape. I never looked at the banana arm bushings so far.

Do 'em both. If you are going to go through the trouble of taking it apart you might as well know that everything is in good shape for a while. Are you going to do the fronts too?

[ischmitz]

Well,

its in the alignment shop as I type. They did a quick check on my work and the numbers were close but still need some tweeking. I might have one spindle bent by about 0.5 degrees. I hope to get it back this afternoon.

Unfortunately, I won't drive it down to Highland this weekend since I need to haul my old engine. And my stupid S10 truck has no AC. A deja-vue of BBR III kreeps up in my mind. I wonder if I should strap the engine to the roof of the C4.......

Ingo

[surflvr911sc]

LOL! I have a bent left spindle for you. think of all the negative camber you could get!

I'll fill the kiddie pool w/ ice water for you.