My Home Alignment Setup
 

Here's what I came up with after looking at the Smart Strings product and saw what some of the racers do at the track.

The key to the whole process is to carefully measure and find the center point of both front and rear suspensions and use these points as a reference to set up the strings. I marked the front crossmember and the tranny with a center punch then hung a plumb bob from each reference point. Then I used a laser line to connect the two center points and transfer them to the front and rear bumpers of the car for ease of setup in the future.

I used a piece of electrical conduit and some plumbers tape for the rear bar and a piece of aluminum box section from my old TV antenna for the front. Set the strings equal distances out from the center points of the F and R suspension and you are ready to measure toe.

I cut a piece of steel square stock 17in. long and used a digital level affixed with a magnetic base to check camber.

The same digital level was used directly on the front struts to check caster.

To get the car up in the air with the suspension in its normal weighted positon I made some simple stands out of cinder blocks and 12 foot 2x10 boards. Plastic "Rhino Ramps" are about the same height as the boards so the car can be driven right up onto the "alignment rack". I used four granite remnant pieces from the kitchen remodel for the wheels to sit on. The granite is flat, smooth and slippery when sprayed with silicone spray so the wheels can move more freely when making adjustments to the alignment.

To hold the steering wheel centered while making adjustments I used a board across the seat and a scissor jack that was sitting around in the shop.

With this cheap and simple setup I was able to attain excellent accuracy of camber within one tenth of a degree and toe within a hair's width. I had most of the components already so cost was limited to the boards and conduit and was under $30.

The best part about this is that now I can make changes to the suspension components or geometry without running off to the alignment shop each time.

Up on the rack

http://forums.pelicanparts.com/uploa...1258351252.jpg

Strings

http://forums.pelicanparts.com/uploa...1258351325.jpg

Center point

http://forums.pelicanparts.com/uploa...1258351391.jpg

Center line

http://forums.pelicanparts.com/uploa...1258351428.jpg
http://forums.pelicanparts.com/uploa...1258351468.jpg

Wheel holding and centering fixture

http://forums.pelicanparts.com/uploa...1258351491.jpg

Wheels move easily on smooth surface when making adjustments

http://forums.pelicanparts.com/uploa...1258351527.jpg

Digital level and camber jig

http://forums.pelicanparts.com/uploa...1258353043.jpg

Sorry about the blurry pics. What I'm trying to show is the laser line intersecting the two plumb bobs hanging from the front and rear suspension center points.

DISCLAIMER: It really hurts when a car falls on you. Everything was very stable but careful alignment of the boards is obviously crucial and a spotter really helps when driving up onto the ramps. Might want to save the cold ones for AFTER the job is successfully completed! :D

Very nice! The slick granite trick is... slick. =)

Along the lines of the disclaimer... wasn't there a warning about cinder-blocks failing catastrophically? I guess that's why you have the wood to distribute the weight move evenly?

Actually I dont think you need the center points. If you measure out from the hubs and the ratio side to side is the same you should be all set. Assuming the car is square.

Looks like a great set up. I did the cinder block thing once too, it ended up being more trouble for me because I did not have the ramps and had to jack. I may have to pick up a set of those ramps.

I always have to commend people who do this as it takes a heck of a lot of time to setup and get right. I did this once, and it's just one of those things that I pay to have done.
How did you level the floor/car?

correct, you want the string center with the hub spindle. center of suspension does not matter
front and rear on one side should be the same, measured to the center of the wheel, and the front and rear on the other side should be the same. side to side does not matter. IE, RF to string 30mm, RR to string 30mm, LF to string 40mm LR to string 40mm.

measuring at the edge of the rim, a difference of 2mm, front edge to rear edge = .3 deg. if you messure hub center to front edge of the rim, 1mm = .3 deg.

this is how my car was just done. he did not square the strings to the center of the car, they were squared to the center of the wheels. he was the mechanic for "spot" back in the 90's. same jig he used on the race car.



that is a very neet idea with the bricks.

One other idea if you dont have $400 worth of granite laying around :-)

two pieces of scrap sheet metal with a little axle grease makes a pretty slick surface so the wheels will move and settle etc.

You can just buy 4 granite tiles at your local tile store. I agree with tobluforu that the whole rig needs to be shimmed level before use. The 4 contact patches must be on a single, level plane.
regards,
Phil

This will only produce parallel reference lines (the strings) if the front and rear track widths (hub to hub) are exactly equal. If track widths are not equal your toe settings will be off.

yes you are correct. my rear track is wider, i dont know how mine was compensated for. i know he did not set it up based on the center line of the car. i know he set it up right because an alignment was done on my car by the PO at a shop that used machines. he confirmed everything was right except my right rear was slightly off, the one that i was having trouble with. very bad tire wear on the inside.

thinking about his jig, kinda like the one the OP has but a little more elaberate, he had holes drilled in the tubes for the strings. the holes were spaced the same for the front and rear. he could slide the bars from side to side and up and down. if he made the front left and right the same to the center of the wheel and the rear left and right the same to the center of the wheel, that would square it. with the holes the same in the front and rear tubes, that keeps the distance of the strings from each other the same front and rear. this would save having to find the center of every car you did and reduce the chance of error.

+1

How often you guys tweaking your suspension? aligning your car? I go to a specialists about 1x a year... well worth the $150 to have it perfect... if I was doing it every month might be a different story...

But very kool setup...

I like doing it......plus I have had issues with the run of the mill alignment stores and the nearest reputable place is a pretty good haul.

I see what you are saying on the reference lines, if the right and left rear are different wrt to the fronts you will not have straight reference lines....but compared to the track width of the car its pretty insignificant. Especially on a street car where there is rubber in the suspension and it moves around.

The laser racks are more precise but as soon as you roll off everything moves a bit anyway.

12 x 12 vinyl floor tiles face to face?

Very nice.

Alternatively, I use four 8x8x16 concrete blocks as you use, standing on the side around each corner of the car, and a roll of pink mason's string to pull two parallel lines along the hub height of the wheels. It works very well, quick to set up, take down, and cheap.

I also use the 24" version of the Husky digital level for measuring camber to 0.1 of a degree.

You might be able to get a ballpark setting by measuring outward from the hub centers but the objective here was to get as precise an alignment as possible using a home made setup. Most 911's have different track widths front and rear especially cars with wide rear tires compared to the front. A quarter inch difference will completely negate any accuracy you might be able to achieve with a toe measurement. Now if the center points are known, then you can add or subtract the difference in track width from front to back and adjust your measurements outward from the hub centers accordingly.

Another point to ponder is that you need to establish a thrust line so your car will go straight. Without the centerline reference to square the left string with the right, you could have a situation where the LF is parallel to the LR and the RF is parallel to the RR but L and R are not parallel to eachother.

I will concede that the set up of this project was time consuming but now I have the tools and knowledge to reset my alignment any time I want to experiment with different toe in/out or camber settings or when changing ride height, after corner balance, etc. Also, I have had a hard time finding a Porsche alignment specialist who really knows how these suspensions work andd how to set them up correctly. Sure, I can drive a long way and pay a lot of money to a known shop but then if I change the slightest thing I'm back off to the shop with checkbook in hand.............

My floor is pretty level. Note the carpenter's level in pic #2 placed across the front granite slabs from left to right. It's very easy to place shims under the slabs to get it perfect. I dont' think this is a critical item WRT setting toe. More important for camber but the digital level has a zero function. Place the level flat on the slab in front of the wheel, zero it, then measure camber.

When you measure from the front and rear hubs to the string during set up where do you measure from? Is the front dust cap removed? or are you measuring from the wheel caps?

I am very interested in being able to do my own alignments so I can adjust and play with it. I would hate to have to drop $150 every time I wanted to tweak it. Also, I'll be swapping out the whole susp. in the next 5 months so I'll need to do it. Essentially, I'd have a track alignment and a street alignment. No need to wear out the tires on the street. With luck I may be able to mark it all so I can simply adjust to the marks and check it, go to the track, and re-adjust some time later that week... or not :) I have seen some cars with camber plates installed that were marked with the individual camber degrees so I thing my plan is not too far off. Comments?

-Michael

Just measure from the string to the center of your hub caps - no need to remove them. Once you've paralleled your strings once, measure and write down the distances of the strings to your hub caps, so next time you set up, just line up the strings the same distance you previously noted, saving you the step of paralleling the strings ( that is if you're not doing TT's smart strings setup). However, if you change camber anywhere, then the hub distances change so the saved measurements are invalid and need to be redone.

Since we are on the subject, do any of you guys set your camber for anything LESS than the maximum you can physically adjust the struts and spring plates to? That is what I do. Only time I would dial in less is if I can not achieve similar camber numbers on both sides.

Caveat: At least half of my miles are on track.

How much are you trying to get, how much are you short, and is it the front or back you're having a problem with?

Seems to me I can only get about -2 in front and -3 and change at the rear. working from memory here.... probably a mistake :)