To make things simple, once I got the rear of my car sitting at the height I like (which is close to ROW spec), I cut a piece of metal that went from the ground to the bottom of the torsion tube. Now, if I ever have to adjust for any reason, I just make sure that both sides of the car are equal, using my handy measuring steel stick, and don't bother with measuring. I did the same for the front. With adjustable rear arms, the process is very easy.

I haven't yet done a corner balance but I am curious to do that and see how much adjusting is necessary.

That's basically what all the 964 and newer do to measure height

ie from the ground to a fixed chassis point
I use 2 different tools
seen here
http://forums.pelicanparts.com/uploa...1444860490.jpg
The plunger has a limited range so you usually have to place a known thickness object(2x4 works) under it and use calipers to measure the turnbuckle length

Quick update. I will post more info later but I picked up the car from the shop for this morning. All I had to drive about 20 miles downtown for a meeting. All I can say is... wow, I love it!

Obviously need some more driving time but it feels like a new (to me) car. The steering feel is improved. It is not as twitchy.

I have a little front left tire rub on the fender lip because I added 21mm spacers.

More later.

Sorry the lighting in this pic isn't the greatest but I snapped this shortly after picking up the car yesterday and driving downtown.

http://forums.pelicanparts.com/uploa...1445003871.jpg

I've got all the data sheets on the alignment, corner balancing and ride height and I'll post it later. I really like the stance of the car now. I dropped the car off at John Holt's this morning to roll the front fender lips to fix the tire rub on the front left. I had a huge grin on my face all the way over to his shop. I just love the way the car feels now.

I have a hump at the end of my driveway. Even at a higher ride height I used to have to ease the car over the hump. No issues whatsoever going in or coming out this morning!

I'll be interested to see your numbers because your new stance is exactly how I want mine, to the T.

Side note: your car is almost a dead ringer for Craig D's here in CO.

Ah, yep. Craig_D have talked about how much our cars look alike. I used to have no tail and he had a duck, while I had H4's and he had sugar scoops. Great minds think alike!

Here's the data from the tech sheet. It's a little confusing the way it's written but here goes. I think some of the numbers written on the sheet are the starting points and others are the final numbers. These are all the ones I believe are the final numbers.

Corner Weight
Front Left = 540
Front Right = 611
Rear Left = 927
Rear Right = 788
Cross = 53.68%

Ride Height
Front Left = 89.0
Front Right = 90.4
Rear Left = 233
Rear Right = 232
Rake = 0.7º

Camber
Front Left = 1.0
Front Right = 1.0
Rear Left = 1.3
Rear Right = 1.4

Toe
Front Left = +.5
Front Right = +.5
Rear Left = +1.5
Rear Right = +1.68

I can understand the front ride height, but where are the measurements from the rear from?

Next time you get a chance, can you check the fender heights? Just curious about those numbers, too.

Those corner weights are a mile off. Some of the other numbers aren't great, either.

On the right size the rear is 24.5 in and the front is at 24.75.

JR, yea I was thinking the same on the weights.

Thanks, Tim!

I just did a couple of cars of the street (nothing done professionally since they acquire the car) and the cross weight were less then .5% between RR/FL & RL/FR.

The Camber should be in the negative range.

Your Total weight is 2866

Your Front/Rear is 1151/1715 (% Ratio of 40.2/59.8)

Your Left/Right is 1467/1399 (% Ratio of 51.2/48.8)

Your Cross is 1538/1328 (% Ratio of 53.7/46.3)

His Cross weight of 53.68 is correct as I round off to one decimal point.

Did he mentioned that the side to side is way off which reflect on you Cross weight reading or try to fix it?

Do you have Waynes book, " 101 Projects?" There is a section on ride hights. Sorry I can't find my book, my mother cleaned my house last month when she came to visit. Anyway, I used the book to set my ride hight after installing an Elephant Racing suspension. The previous owner lowered the car too low and it drove like a lumber truck.
The tie-rods were angled upward and I fought bump-streer. The book is the best source I've found for determining ride hight. There should be something on this site in the tech. section. I actually, raised my car to slightly above European ride hight, then took it to a shop and had the car corner balanced and aligned. Not a good idea to measure from floor to fender.

Also, if you take it in for corner balancing and alignment, the shop can set your car to the optimal hight. The owner of the shop told me I had it pretty close. The corner balancing and alignment cost $400 and I was very happy with the way it handled. It seemed to be a good investment. Look for Waynes write up on ride hights and corner balancing.

Look under 911 tech. articles.

I found this under tech articles. It's the same write up as Waynes book. If you look under tech articles you will see illustrations. Hope this helps. At about the 3rd paragraph begins with ride hight the rest of the article might also, be helpful.

Gary


Another problem to consider is bump steer. Lowering the car will result in the tie rods no longer being perpendicular to the ground. While this shouldn't affect handling, when the car travels over a bump, the steering wheel will rotate violently in your hand. The solution for this problem is the installation of the bump steer kit (See Pelican Technical Article: Installing the Bump Steer Kit). This kit raises the steering rack back up to be aligned with the tie rods, thus reducing the amount of bump steer. I recommend that you install this kit underneath your steering rack if you lower your 911. Installing the turbo tie rods (Pelican Technical Article: Installing the Turbo Tie Rod Kit) will also help solve bump steer problems.

The lowering procedure is simple, and all adjustments should be made with the car level on the ground. Make sure that you have a tape measure handy when you start so that you can keep both sides of the car at the same level. The factory measures the height of the front suspension as the difference between the height of the center of the road wheel, and the height of the center of the torsion bar. Therefore, as this difference increases, the car rides lower to the ground. The standard USA spec for the ride height for almost all 1965-89 911s is 99mm ( 5mm. The maximum difference between the left side and the right side should be less than 5mm. The European specification is 108mm ( 5mm. To lower the car to this height, simply loosen the adjustment bolt on the front suspension. Again, make sure that the left and right sides of the suspension are equal. If you have difficulty turning the screws with the car on the ground, lift up the front suspension a bit using a floor jack. Make all measurements only after you have pushed down on the car a few times to level it. Also make sure that your trunk is empty and your spare tire is installed in the front trunk. Keep in mind that the car will also ride lower with a full tank of gas (approximately 150 lbs of extra weight). There may also be a spacer installed on the top of your shock tower that can be removed if you are lowering your car.

Balancing the left and right height of the car should also help to improve your handling. In general, the adjustment screws for the left and right sides should be dialed in roughly equal amounts. If they are not, then this might indicate that one of the torsion bars is old and worn, and needs to be replaced. Another method of checking the left to right balance is to measure the distance of the wheel to the top of the fender. This however, can sometimes give inaccurate results if one of your fenders is slightly tweaked.

The lowering of the rear suspension is a bit more complicated. In a similar manner to the front of the car, the factory measurements are based on the difference from the center of the torsion bar to the center of the road wheel. To arrive at this number, measure the height of the bottom of the torsion bar cover from the ground, and then add 1/2 the diameter of the torsion bar cover. Then subtract the height of the center of the wheel. For the European 911SC, this measurement should be 16mm ( 5mm (USA 37mm ( 5mm). On the earlier cars, this distance was 12mm. The maximum difference between the right and the left should be no more than 8mm. Check the Porsche Technical Specifications Booklet for your year car for the exact specifications.

The rear suspension uses a rear trailing arm that is sprung using a torsion bar. This torsion bar is connected to the rear of the trailing arm via a long radius arm. Adjusting the position of this radius arm with respect to the torsion bar is what changes the height of the car.

In order to adjust this height, you need to remove and reset the splines on the rear torsion bars. For more information on removing the torsion bars, see Pelican Technical Article: Replacing/Upgrading Torsion Bars. The inside end of the torsion bar has 40 splines, and the outer end of the torsion bar has 44 splines. This clever arrangement allows you to make incremental changes in the torsion bar height. Simply move the inner spline clockwise one position, and the radius arm counterclockwise, and you will lower the radium arm by about 5/6ths of a degree. Repeat this adjustment procedure, until you have achieved the desired ride height, and both sides are equal in height.

James Bricken of Pelican Parts, offers the following tip on achieving the rear height and balance that you are looking for:

Often one end of the torsion bar, or the other, will stick in place causing a loss of base line (which means you have to start from scratch. The way I do it (and I do it often), is to remove the lower-rearward bolt on the torsion bar cover and the lower shock bolt. This allows you to fully drop the rear suspension. Then I use a Smart Tool (but a simple leveling protractor works as well) and measure the inclination of the spring plate. Next, I scribe a line on the trailing arm where the spring plate meets it. This gives me a good approximation of where it should be when I reassemble it. Then I take the whole thing apart, generously lube the new torsion bars and install them. I then install the spring plates on the torsion bars just slightly and take measurements with the Smart Tool, adjusting them until I get the least amount of change from the original setting. Once I am satisfied that I am close, I put the rest of the suspension together, without fully tightening anything except for the camber and toe bolts. Once the car is on the ground, and I am happy with the results, everything else is then tightened down.

An excellent method for synchronizing the settings of the left and right rear torsion bars is to use a level to determine the amount of adjustment required. Aside from measuring the total height of the rear suspension, you can also measure the angle that the rear radius arm makes with the horizontal. Place the car on a flat and level surface, and then place a bubble level tool on the radius arm. You can adjust the height of the bubble level tool by placing small spacers underneath each end of the level. Once the level is adjusted, compare the angle to the opposite side by taking the level and the spacers and placing them on the opposite radius arm. Adjust the setting of the torsion bars as needed to make sure that the level of the left and right suspension are exactly equal.

If you have a later model 911, then you're in luck, as you don't have to remove the torsion bar covers and radius arms to get at least some degree of adjustment. On these cars, the radius arms were equipped with an adjustment screw. To raise or lower the rear of the car, simply loosen the large nut and bolt closest to the torsion bar. Then rotate the other bolt located next to it. This bolt is eccentric, and will cause the rear of the car to be raised or lowered as you turn it. Adjust the height as described previously, and then tighten the bolt located nearest to the torsion bar. Make sure that you don't touch the two nuts located towards the rear of the car: these adjust the toe-in and the camber for the rear suspension, and should only be adjusted by a trained professional using an alignment rack.
After you've made all these adjustments to the ride height of the car, it's a wise idea to have an alignment expert check and align the car, especially if you have had to remove the rear radius arm. Make sure that you have the ride height set before you take the car in, as subsequent adjustments will alter the alignment specifications. Drive the car for a few miles, and then double-check all your measurements. Make sure that the left to right height of the car is the same after driving. When adjusting your 911 ride height, it's smart to consider the weight balance of the car. With the correct alignment dialed in, a properly set up 911 will have approximately 40% of the weight on the front wheels and 60 % on the rear, with the chassis riding very slightly lower in the front.
losest to the torsion bar cover keeps the ride height secure (green arrow). The bolt second from the right is used to adjust the height of the radius arm (red arrow). There is some degree of adjustment available, but not as much as can be achieved with the removal of the torsion bar. The bolt that is furthest to the rear of the car is the rear camber adjustment (white arrow). The bolt next to it adjusts the rear toe-in specification for the car (yellow arrow).

As determined by the factory, the measurement for determining the front ride height is calculated by subtracting the height of the center of the road wheel from the height of the center of the torsion bar.
As determined by the factory, the measurement for determining the front ride height is calculated by subtracting the height of the center of the road wheel from the height of the center of the torsion bar. The larger the number, the lower the car sits to the ground.



The rear height measurement is similar to the front end measurement.
The rear height measurement is similar to the front end measurement. The specification for the rear height is determined by the difference in the height from the center of the torsion bar to the height of the center of the road wheel.