Memorial Day Project - Final Chapter

On to day 3 of my project. I started a seperate thread because the image load time was getting long on the other. You can find the first 2 days of the project under the subject "Memorial Day Project".

Having completed the tbar installation, neatrix bushing installation, and setting of ride height on days 1 and 2, it was time to get down to some serious corner balancing.

I purchased a portable scale for testing corner weights. This scale measures 1 wheel at a time and cost about $155. It's not accurate, but it is precise within about 10 lbs and repeatable when used properly.

I opted to do this myself because I was getting quotes of $350 to corner balance and 4 wheel align. With two 911s that will each likely need this more than once as I continue to tweak them, I thought the portable scale would be a good investment.

It took quite a while to figure out how to get repeatable measurements. Here is a picture:



On the right side you will see how the manufacturer recommends you use the product. Not good. It WILL scuff your wheels, I tried padding - didn't prevent the scuffing. I put on my track wheels to do this, since I don't care about their appearance so much.

Putting the scale on the rim not only scuffs, it tends to slip around which makes for a less repeatable measurement.

I decided to put it in the hub, which I didn't care if it scuffed and it didn't slip. I would put the scale right at the edge of the hub to make sure it was in the same place each time.

Problem was the unit was too tall for the hub. So I picked up a new peice of box section metal and made my own base the had the correct height. You can see this in the left hand picture.

The following image shows the correct technique for getting repeatable measures -



You can see my lovely assitant pulling a peice of paper out from under the tire. When the paper moves, the wheel is off the ground and the reading is taken. Don't lift any higher, this will change the reading.

On the right you see the guage and a bubble level. It is critical that the guage be level when the paper moves. If it is not level, the reading will not be accurate.

This takes 2 people, one to lever and watch the bubble - the other to move the paper and take the reading.

Takes a while to get the technique, but once you have it .... You need to take several readings to be sure it is repeatable. Your measurements should repeat within 10 lbs. Each time we measured a given wheel we did it 3 times to be sure we had a repeatable measurement.

It is also critical to be on a flat and level surface. Once I had it dialed in, I turned the car around and repeated the measurements just to be sure the floor was level.

Upon first measurements I found the car had a bit too much weight on a diagonal. Tweaking the passenger front a bit brought it in line. It took a few tries with repeated measurements to get it right. After each adjustment, you need to drive the car around the block to let the suspension settle in.

By the time we finished we had taken 11 seperate weighings of all 4 wheels. That means 4x11x3 = 152 seperate measurements.

I opted for 24.5 inches at the rear fender, 25 inches at the front fender. This is about .5 inch lower than Euro spec.

The car is used for street and track events. I felt that with the stiffer tbars I could get away with the low ride height without problems, plus I am carefull. On the track I use 15 inch rims which reduce ride height to 24 rear 24.5 front. Pretty agressive.

Here is a before and after closeup of the rear fender height and spacing:



Close those unsightly gaps!

Here is a shot of the car before and after, top is before:



You can see the change in gaps. The car was riding a bit high before because I put in gas shocks and have taken some weight oiut.

The new ride height looks much better. The wheels really fill out the wells. The difference is more dramatic in person than these pictures would indicated.

As another reference point, here is the lowered car sitting next to my '77 targa.



So.....what's the bottom line -

I still need to get a 4 wheel alignment so driving impressions are limited so far. I have put a few miles on and some things are clear.

The 21/27mm are fine for the street. It is marginally stiffer going over bumps, but it is no big deal. I would describe it as more "lively".

The car corners very flat. Dive and squat are noticably diminished.

The car does exibit more oversteer. It turns in quicker and feels more responsive. I wanted this.

The appearance is much improved.

The only time I scraped was with the track wheels on pulling into a driveway, these sit .5 inches lower than street gear.

No Squeaks.

The job was fairly involved. If well planned, it is not incredibly hard but it is a lot of work. I would recommend it only to people who are experienced and comfortable working on cars. It requires some specialized tools. It took me 3 days, working 6 hours or so each. I am very tired now.

I got the tbars used for $275. I bought $200 worth of tools. I bought the Neatrix bushings for about $40, the rack spacer for about $15. I allready had the Konis, but if I didn't they would have been part of this upgrade (another $550). I still need a 4 wheel alignment, probably another $100.

So all told I this cost about $620 and 3 days.

Was it worth it. You betcha, can't wait to get it on the track.

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Chuck - '86 Cab, '77 Targa, Family Truckster


[This message has been edited by Clark Griswald (edited 07-06-2001).]

Thanks Clark, not quite ready to corner balance my car yet, more suspension work to do, but it was great to see how you went about it. Thanks for taking the time and pictures.

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John Forcier
69 911T