Alignment tomorrow.... what should I set it at?
 

Well, I have reserved the alignment rack at the hobby shop for 4 hours tomorrow, so that should give me plenty of time to sit and play with it.

The computer has all of the specific factory specs for my car in it, but I want a little more "experienced" info from you guys...

I'm really worried that I'm not going to be able to get the front camber adjustment even close becasue of the amount that the car has been lowered.
Someone told me that it is ok to "wollow" out the shock mounting holes to allow for more movement. Is this the case?

ALso, when I lowered the rear spring plates, did this change the camber setting? I didn't mess with the actual camber eccentric, but there seems to visually be more negative camber to both rear tires now.

I'm trying to find a good, streetable compromise here.

What is the maximum degrees of negative camber that I can run that isn't going to totally eat up my tires within 3000 miles?

Many of you gave me some pretty good tips on the toe in/out settings, and I think that will be the easy part.
The caster shouldn't be a problem... it's just the camber that worries me.

Is there anything else I should concern myself with???


Thanks, as usual,

I think you want 0.5 degrees more negative camber in the rear. When I had my car corner balanced and aligned I had them set it up for street/track. I have -0.8 degrees in the front and -1.3 degrees in the back. I plan to go to -1.0 and -1.5 next time but I have no complaints about it now. The car is great on the track and street and I haven't had any abnormal tire wear. The track ate my tires but they were wearing fine on the street.

Don's camber settings sound about right to me...but Lee, your earlier spring plate adjustments? Look at everything...including toe...front and rear. Your hand skills are far above mine. But me? I hire pros for alignment. The Voodoo science factor...

Leland, I went to the place recommended by JW and told him I wanted a daily driver that is set up for sport and AX. I wanted a really responsive car, I told him. I got that, but I am thinking I'd like more toe in. Like yours (though perhaps not as severe), my car is a bit unstable at higher speeds and it does not like to just go in a straight line. I think a tad more toe in would solve my problem. Also, the shop corner balanced the car while they were at it, and it is set up for a 165-lb driver. That is why the left and right specs are not identical. Presumably they are when I sit in the car. Before I removed my A/C that is. Folks that understand alignment will LOL when they see the "previous" specs.

Previous Front
Camber L -0.39 R 0.14
Caster L 6.48 R 6.87
Toe L -5.2mm R -2.1mm

Previous Rear
Camber L -1.51 R -2.53
Toe L 0.0 R 0.0

Current Front
Camber L-0.86 R -0.78
Caster L 6.69 R 6.71
Tow L 0.0mm R 0.0mm

Current Rear
Camber L -1.58 R -1.50
Toe L 0.0 R 0.0

Bump. Can't believe this thread was on Page 3 today. I think we should show more respect for Chancellor Pate and besides, I really do think some folks will be amused at my old alignment specs. Good luck today, Leland.

Thanks for the stats Jim.

I've printed this out and am going to take it over there with me today.

Does anyone have any more imput about "wollowing" out the strut tower mounting holes to allow for more adjustment?

I wouldn't try opening up the holes. I think the camber restiction is because of the mounting plate. The plate can only move so far before it hits the strut tower. I've heard the only way to increase camber adjustment is to change to a monoball plate.
If you're setting up for street/track, you shouldn't need more than -1.0 camber in front. That shouldn't be a problem with the factory holes.

I want to raise my car to the correct height, and I plan to do this myself. I'll corner balance it too, but my questions are about alignment.

How do you find a hobby shop alignment rack?

What are the costs?

Is this something I should leave to the professionals (they want $250)?

The PO said he did his own alignment, turns out it was just toe-in.

Thanks.

If you need to remove material it all depends on which way you need to move the camber.

My car had been lowered and I was having trouble setting the camber low enough with the shocks all the way out in the towers. Here is where I "wallowed":

http://forums.pelicanparts.com/uploads/DSC00731.JPG

I did a thread on this but damned if I can locate it.

you cant get into much trouble by opening up the holes for the strut and mounting bolts.. the strut mounting plate willl run into the shock tower.

If you get the car on a lift get a strong light and look up the strut tower and see how much room is available between the mount and the inboard side of the strut tower, you could then see about how much movement is available and open all the holes up that amount.

I'd agree that you should be able to get the negative camber you (should) want without removing material. I'll warn you again that I wish my car had just a tad bit of toe in in the front. It was set up without any because the guy listened to me when I said I want the car to snap-steer in AX events. But this causes twitchiness at speed...not good. Perhaps about a degree of toe in. Then what happens is that 'road forces' push the front wheels outward so that they are more precisely parallel while driving. Mine would be facing slightly outward, causing the wandering.

I'm actually worried about positive camber adjustment....

With the significant amount that i've dropped the front suspension at the torsion adjustment bolt, I'm worried that I've in effect, created too much negative camber... and that the factory mounting holes won't allow for enough correction to the geometry.


Thoughts???

Leland the mounting holes can be elongated in either direction. What limits the amount of travel after you slot the holes a bit is the strut tower, the strut mounting plate will run into the tower (whether inboard or outboard)

Todd Serota, the guy who runs the Tracquest Drivers Ed events posted what he thought to be good SC alignment specs on the Rennlist 911 mailing list a while back.

If you changed the ride height, you probably changed the toe, by changing the angle of the tie rods to the steering rack. If you managed to get some toe out, that could explain the twitchyness.

Tom

Leleand

You are describing the exact problem I experienced.

There are three places that can limit adjustment range.

The limiting factor in my case was the size of the "big hole" in the tower and material was removed as shown to open it up, maybe 1/8 inch or so.

The next likely factor as pointed out by others is the bottom of the plate running into the side of the tower. I don't think you can fix that one except by going to camber plates (fyi, keep a future eye on those crafty boys at Elephant for a slick solution!)

The other place that can limit travel is the holes for the camber plate bolts. Those holes can also be opened up a bit if needed.

You just need to look and see which of these items is your limiting factor.

Okay, I just had one of those "Oh yeah" experiences. If Leland lowered the front, and if my assumptions are correct (that the tie rods angle down, and connect with the wheel behind rather than in front of the axle, a safe assumption) then the act of lowering the front would have increased toe out. Causing wandering. Duh.

Leland,
Whatever you did please let us know the results. I just replaced front A-arm bushing (Thanks Chuck Moreland - Excellent article, I added the zerks as well), New neatrix in the rear, new torsion bars 21/26, turbo tie- rods and a bump steer kit. Also lowered her to 25 in the rear and 25.5 in the front.
I've been up to my elbows for a week. Oh not to mention fixing the steering bushing and putting a short shift kit in.

I was going to the alignment shop this weekend myself and would be real interested in the results.
I did some searching and had written down some target numbers I was going to set to :
Front - Toe (0), Camber (-1 deg), Caster 6 deg.
Rear - Toe(-15 minutes), Camber (-1deg)

I'm open for any comments, the car will be used on street and has 7 & 8 Fuchs with 205/55 R16 Front and 225/50 R16 Rear, Tire pressure at 32 front and 35 rear.

I would love to have some feedback as well. Thanks folks...

lee

you got ba's book?

i'm pretty sure it gives some specs. my copy's at home and i my home pc's busted so can't get back til monday now.

i was going to start with his suggestions. my shop keeps records of the alignment so that you can try different settings and always get back to where you started. (i believe you got that as well).

Guys:
No real issues here except...
Superman.. you want to shoot for one degree of toe-in ?? What?

Yeaah...you want "some"...maybe 15 "minutes" total ( 1/4 degree). A full degree?..I don't think so, IMHO !

Well here's the latest....

I think we screwed up. :(



It took us so long to get thgings going right yesterday that we only messed with the rear alignment.

The guy who operates the hobby shop is a real nice fellow - but he doesn't have a clue when it comes to porsches. He couldn't really grasp why I'd even want a little negative camber...

All the same, I took his word as gospel because he definately knew more than me when it comes to operating the rack.

After he looked at the adjusting bolts on the spring plates (camber and toe) he said we needed to raise the rear tires off the ground to make the adjustments.... becasue with the weight on the tires wouldn't allow for any adjustment... so he raised it up and then we proceded to dial in all of the adjustments.

After 3 1/2 hours of cursing and wishing we had the right tools (12MMM allen socket) we finally got everything aligned.

The specs with the car in the air were as follows:

Camber L- 1.4

Camber R- 1.4

Toe L- 0.00

Toe R- 0.05 (as close as we could get it)


I thought everything was fine until we lowered it back down to get it off the rack... I could really see ALLOT of negative camber and I went to look at the computer display again... our 1.4 degrees on either side jumped to 3.5 degrees!

I guess i had thought that they had somehow calibrated it for the adjustment in the air... I no longer think this is the case.
When i asked him about it, he said, "well, yeah, when you put weight on the tires, it's going to cause them to push out" .... .... Well DU'H!!! :mad:

I thought they knew what they were doing... oh well, it only cost me $22.

So now I have a car with 3.5 degrees of camber in the rear... I'm going to try and correct this today. But first, I want some more information from you do-it-yerself-aligners.

The computer only said to loosen the camber and toe bolts to make adjustments... my Bentley books said to loosen those two *plus* the two other banana arm securing bolts... Is this nessecary?

Secondly, what is the sequence of events here?
Are you supposed to remove the tire every time you make an adjustment?
They told me that wan't practical because you lose you readings every time you remove the "
"laser wheel attachment thingie".
So, were we wrong to make these adjustments while the car was up in the air?

If so, what's the way to do it?

If not, how do you make adjustments to the camber and toe bolts with the weight of the car resting on them? We couldn't budge them, that's why he said we needed to do it up in the air.


Ideas?

Lee, here's a post from a couple weeks ago. I'm getting set up to do it at home. Don't have a hobby shop :( to use. And the Les Schwab deal doesn't work. They don't have a clue.

I'm hopeing someone jumps in and gives you the step by step.

http://forums.pelicanparts.com/porsche-911-technical-forum/76304-diy-alignment-corner-balance.html

Bentley shows loosening the four bolts ( trailing arm to torsion plate ). After scribing its location. Then adjust. But we all know how accurate this book is. So would like to here it from one of us thats done it.

FWIW. I've decided to buy the Hit Man alignment tool. Smart Racing's camber/caster guage. And the toe guage from Solotime.
About $400. As for scales, haven't decided yet. $$$, but I was given 10 acres of hay to cut for free. So that should make me another $1000. So I might spring for the digital ones.

FYI. I read the 911 section in Les Schwabs book. Not even close.

Leland

All adjustments are made with the vehicle weight on the tires. Period.

As you experienced, jacking totally changes the settings.

There are four bolts you need to loosen on the spring plate to adjust camber and toe. Sounds like you only loosened two, explaining why you couldn't move anything.

Sounds like you found the camber/toe bolts, that's two of them. The other two are at the rear of the spring plate and serve only to lock the settings into place.

The following picture shows the four holes that hold the bolts you need to loosen. The two bolts shown are for ride height and should be left alone.

http://www.pelicanparts.com/ultimate...witharrow2.jpg

If memory server, the front most rounded hole adjustes toe, the slotted hole in the middle adjusts camber. The rear two are slotted. They allow movement of the trailing arm for alignment but their function is merely clamping, they are not adjusters.

You might find this thread useful:

http://forums.pelicanparts.com/porsche-911-technical-forum/4697-alignment-woes.html?highlight=camber

Chuck, I was thinking after I posted. Wouldn't it help to give both sides a squirt of PB Blaster the night before ? In between the sandwiched part.

Cary,

I'm not sure what you mean by the sandwiched part? But it can't hurt to hit to 4 bolts with PB.

20+ years of exposure to road schmegma can make them tough to turn!

Guys:
Allow me to build on Chuck's excellent reply...
The factory delivers the later ( 78+ ?) cars with 2 piece rear spring plates. It is slotted to allow a "small" amount of height adjustment whe you're all done..maybe 3/8" to 3/4". Unfortunately, as delivered, these are set up to allow RAISING the car ( only), ...the factory wants a fudge factor built in to compensate for spring sagging over time. So the adjuster is crammed against one side of the slot..it's not center-punched.
Once everything is apart, you might want to "center" the 2 pieces relative to one another. That way, when you're all done, you have at least a small chance to go either up or down by a small amount to fine-tune ride height.
---Wil Ferch ;)

Update

I went back in there as soon as I got off work and this is what they had to say.

The senior wrench told me that the computer was supposed to compensate for the wheels being lifted... Meaning that it gets a base reading with the car on the ground, then you raise the car up and the computer calculates the difference. So, that in theory, when you make adjustments in the air, the alignment readout is already compensated.
This sounds like a ligitimate answer to me... however, that obviously did not happen yesterday. He said that something went wrong,... (hit a button) and it didn't compensate.

I have another apointment to go back in there on Tuesday so we'll try it again.

Any other tips?

Yes, ignore what he is telling you. I can't fathom how the machine could possibly make an accurate compensation given all the variables involved.

There is no reason to jack the car. The adjustments can and should be made with the weight on the tires.

There are starving kids in China that would kill for 3.5 degrees of negative camber in the rear!

No kidding. If I were you, Leland, I would have some fun with all that negative camber before Tuesday. Your car will probably feel more stable in a violent turn, than in a straight line. So, if the car feels better in violent turns....make your car happy.

Chuck the sandwiched part I was trying to describe. Was the space between the trailing arm and the spring plate. I found quite a bit of dissimilar corrosion on the eccentrics.

How did you clean up those spring plates and T-bar covers in the tech article ?

Thanks

Cary

I used castrol purple and a pressure washer on everything. The cad plating on the covers was still in good shape. I painted the spring plates.

As far as I know this is impossible and incorrect. I think you need to do the whole thing all over. Doesn't that alignment bench come with turntables, slip plates and wheel stands?