why can't we get a C/balance and ride high adjustment?

[rdane]

I have a SC that has never been wrecked and shows no damage to verify that fact.

I asked here a few weeks ago about my right front brake locking up.

Turns out the starting corner balance was:
LF 934 RF 270
LR 593 RR 1159

But the ride height was
24.5 on all four corners.

Easy enough to figure out why the right front brake locked up now.

After a 3 full days of work ( they admit it is a problem car for unknown reasons to them) by one of the best shops in the area the corner balance (with driver weight added) ended up:

LF 639 RF 528
LR 852 RR 857

Car drives a lot better with the balance and certainly brakes better now but the ride height now sucks.

Here is the current ride to get that corner balance.
LF 24.5 RF 26.25
LR 24.5 RR 25.10

Car's R/H look from the driver's side. The passenger side R/H looks like a 4x4. The R/H is notable and off balance with the front end clearly higher than the rear on the passenger side. We are fairly positive neither the struts or spindles are bent.

Anybody have some idea of what is going on? More imprtantly how can I fix it? I have sunk a bunch of money into the car in the last year including the most recent project of new T bars (Sanders 22/30) and solid bushings all around that were the last things to do before the corner balance and lowering. I "thought" I was building the perfect 911 but this is putting that myth to rest.

This is really discouraging...I need some help!

Short of a new car any suggestions would be appreciated.
Will tearing the entire front end off both sides and starting over again with new struts solve the problem? Thanks guys!

[ischmitz]

I would check the struts and the shocks. Something must be wrong on your car. Maybe the left front strut is shot or the right rear shock.

We (MikeZ, DBuyers, and myself) were playing with a corner balancing scale a couple of weeks ago. We had three cars to play with (71, 74, 86). After slight adjustments we could get the corner balance within about 20 to 40 pounds on each car. MikeZ's car had adjustable spring plates and made things easier.

Ingo

[rdane]

All new shocks...Bilstein sports front and back less than 1500 miles ago. Besides the new T bars and bushings, new ball joints, Elephant triangle front brace, turbo tie rods, 7&9 fuchs.

At this point I am hopeing a new set of Bilstein struts would solve the problem. The original Boges are what is on the car now.

[emcon5]

Originally posted by rdane
All new shocks...Bilstein sports front and back less than 1500 miles ago. Besides the new T bars and bushings, new ball joints, Elephant triangle front brace, turbo tie rods, 7&9 fuchs.

At this point I am hopeing a new set of Bilstein struts would solve the problem. The original Boges are what is on the car now.

My suggestion is to stop buying parts unless you know what the problem is.

You say you installed the T bars. Did it exhibit the LF locking problem before you installed the T bars?

Tom

[rdane]

"Did it exhibit the LF locking problem before you installed the T bars?"

The answer is yes. I actually thought the caliper would need a rebuild but the brakes are fine now with new pads, rotors and brake lines. I first noticed the brake lockup problem after that work was done. At that point only new shocks and the brake work had been done. Balance weights posted are BEFORE and after new t bars.

All the work has been done by a very reputable local shop with a long winning Porsche racing history. The upgrades have been mine, no salemanship going on.

The parts upgrades were done over time all the while assuming the car didn't have any serious problems in the suspension. I listed the upgrades to give everyone an idea of what had been done. I wasn't buying parts to solve problems only to upgrade and refurnbish a 25 year old car. The post is a feeble attempt to indentify and solve what is clearly now a problem.

Suspension upgrades, tbars, bushings, brace, C/B, alignment and lowering came last to get it all done in one go. Car's back in the shop the second time.....had a track day I didn't want to miss. But the shop is the first to point out is aint right as is. I suspect they aren't any more pleased or less frustrated than I.

There are lots of knowledgable folks here. I thought maybe someone had seen this before. Something like, "OH, ya, saw the same thing which turned out to be a bent strut but you sure couldn't see or measure while it was on the car. Replaced the struts and car dialed right in."

Looking for a simple answer that has stumped a maybe half dozen professionals for the moment.

[Eric Coffey]

Tom brings up a good point/possibility. If your ride height is tough to equalize, while still maintaining good corner weights, you may have accidentilly set one (or more) of the new T-bars off by a spline or two. Just a guess though.

[Early_S_Man]

I am suspicious of your triangle brace ...

If you are truly intent on finding the answer ... disassemble the front suspension and take the struts, A-arms, and crossmember to a dealer and have them tested in the factory measuring jigs. Just because there is no visible damage does not mean one or more struts or control arms hasn't been bent by a curb or speed bump!

I don't think any amount of discussion will get you an easy answer. Testing and measuring the parts is what needs to be done next. i am somewhat surprised that the shop didn't make the suggestion to test them.

[RANDY P]

That's tough, and it certainly is a weird problem. Before you dump any more money in parts, you may need to take it to a shop that specializes in collision repair for a 2nd opinion. Not trying to say that your shop isn't up to par, but if the car has in fact some damage that may be overlooked, a good suspension "repair" shop (not a race shop) may be needed to find it. Not too many places can align a 911 properly AND do diagnostic suspension work but try:

Try Byron at Tru - Line. Their shop does speciality repair work like this all day long. Although they're not as well known as some of the other alignment shops, I can tell you firsthand that the workmanship is top notch - not only can they do all the rest of the corner balancing and height adj, but their main work is alignments and suspension repair after collision. They do know 911's. Great people. They don't give it away, but it will be done right.

(206)325-3340. Tell them I sent you (Red 81 coupe)

good luck

[911pcars]

Rdane,
Randy P touched on this in his reply regarding a collision shop. Instead of beginning by inspecting/replacing suspension pieces, I'd suggest putting your car on an chassis alignment jig to determine whether your tub is off. The specs are in the factory manuals. Juggling torsion bar settings will either get you correct height OR close-to-correct corner balance, but if the chassis is not straight to begin with, you won't get both. However, this might open a can of worms. If the chassis was not straight prior to body work being performed, then pulling it back to spec may cause some shift in panel alignment. Let us know what you find out.

Sherwood Lee
http://members.rennlist.org/911pcars

[dad911]

Are you sure they disconnected the sway bars to conner balance?

New solid bushings binding?

I also had a bad insert in a front strut that would 'bind'.

[Thomas Owen]

I am with Randy and Sherwood on this - do not buy anything else until you have had the car checked on a chassis jig. You may find a twist in there that no amount of new parts can compensate for.
Good luck and keep us posted -

[gtu935]

Holy cow, I just had the same exact problem with a 911 1987 that we have been working on for the last two days. The rf wheel wheight is 275 with the rr wheel weight at 1190 the lf at over 800. We have check everything every which way. it was good to see your thread about the problem. This car we are working on is completely sqaure and the align, is better than perfect. We have a brand new Hunter align. rack that we are using to check all the align specs. We have checked the control arms, struts, upper strut mounts, we left the sway bars disconnected,(to rule them out). we checked everything. This car drifts violently to the right.

[rdane]

Funny thing on this car is it tracks fine. In threshold braking from 100+ mph it stays on line easily. Did before the corner balance and suspension upgrades and does so even better now.

Admittedly I am a novice driver but the car is still exceptionally easy to drive on the track even in wet conditions. Good testimonial to how well the 911 is set up...even when it is screwed up. I'll know more latter today.

[gtu935]

Keep me posted on this problem. We have just reset the corner balance and ride heights and are just going for another road test.

[ewave]

Originally posted by rdane

After a 3 full days of work ( they admit it is a problem car for unknown reasons to them) by one of the best shops in the area the corner balance (with driver weight added) ended up:

LF 639 RF 528
LR 852 RR 857

Car drives a lot better with the balance and certainly brakes better now but the ride height now sucks.

Here is the current ride to get that corner balance.
LF 24.5 RF 26.25
LR 24.5 RR 25.10

I personally doubt the competence of the shop:

If you were to remove 1.2" from the RR and 1.2" from the RF the corner balances would STAY THE SAME, but at least your ride height would be closer to even. They should know this, and I wonder why they didn't adjust it this way to make your car closer to ride height balanced.

I spent three days doing my own corner balance on my 89 930. I found there was a slight compromise between ideal corner balance, and even ride height on all four corners. The information you have provided either suggests that the car is bent, or the ride height is being measured incorrectly.

The compromise that I would recommend is remove 1.2" from the RR and the RF:

LF 24.5 RF 25.05 (error + 0.55")
LR 24.5 RR 23.90 (error - 0.60")

[masraum]

I agree with Paul, since the right side is too high in front and back you could lower that side evenly and the balance would change marginally, but equally from the left to the right. From the sound of things the adjustment is just off.

[Chuck Moreland]

Originally posted by rdane

After a 3 full days of work ( they admit it is a problem car for unknown reasons to them) by one of the best shops in the area the corner balance (with driver weight added) ended up:

LF 639 RF 528
LR 852 RR 857

Car drives a lot better with the balance and certainly brakes better now but the ride height now sucks.

Here is the current ride to get that corner balance.
LF 24.5 RF 26.25
LR 24.5 RR 25.10

Car's R/H look from the driver's side. The passenger side R/H looks like a 4x4.

You don't need new shocks, struts or any other parts. And I personally guarantee it is not your Triangulated Strut Brace! Don't spend another penny on parts.

I have a tech article on the topic here:
http://www.elephantracing.com/techtopic/cornerbalance.htm

The adjustments must be performed considering how it affects CB and height simultaneously. This can be tricky but with a little thought and experience it's not so tough.

You can achieve CB by adjusting one wheel, any one wheel! But to acheive CB and ride height simultaneously requires adjustment of two or more wheels concurrently.

Looking at your numbers, your CB is unacceptable. Your ride height is ridiculous.

Based on your numbers, what needs to be done is to lower the RF and RR simultaneously while leaving the left side alone. Re-measure and see what you have. This is an iterative process and will reqiure several passes.

[dad911]

Do you still have the stock front sway bar? I believe the stock sway bar on a 79sc is not easily disconnected, it attaches to the 'A' arms without drop links. If they didn't disconnect sways when corner balancing, then the sway is pre-loaded and corner balance will never be correct.

Also, if you add up the totals before and after, the car got 80 lbs heavier?

[Chuck Moreland]

The sway bar isn't the culprite. Proper CB technique on a car with non-adjustable sway bar is to leave it connected during the CB process. After all it will be connected when you are done right?

Adjustable sway bars should be disconnected during CB. Then after the job is done reconnected and adjusted for no preload.

The solution here is a matter of turning the right screws the right amount. The hard part is deciding which screw to turn and how much.

[billwagnon]

I had my car's ride height fixed - but they had no concern at all about corner balancing, and it's off. My plan is to reindex the front torsion bar so the front left wheel isn't so heavy.