solomonschris

Actually, it was just my attempt at humor. My two favorite avatars (for very different reasons) are yours and JohnnyBahamas. I had my 95 corner balanced, but it had FSD's, ROW springs and full alignment done at the same time. The car was transformed, but the Monroes were shot at 50k, so I don't know what to attribute to corner balance.

Bill Verburg

I've always had my street cars corner balanced, it's a small price to pay to be sure the car is at it's best

Kika

AGREE!

When I took my car to West End, I asked Darin how necessary it was to have my car corner balanced, and his thoughts on it were, Porsches are high performance automobiles, it should be maintained at high performance levels.

It would be like buying a high performance road bike and using it to cruise around on the beach.

Van1

The way I see it, this analogy perfectly describes the majority of 993 owners and Porsche owners in general. Not that there is anything wrong with that but it's a small percentage of owners that have any real experience pushing these machines in a race track environment where things like a corner balance would really matter.

nile13

Ummm... let's see. If we are corner balancing a street 993, are we doing it with a spare tire and tools? Are we racing it that way? Are we balancing with you in the car? Aligning with you in the driver's seat?

It's just some example of little details that need to be addressed. I'm perfectly willing to address those details on a race car. On street car? Not so much.

Van1

You are probably right, this may even be an overkill item for us driving our street cars on the track in non competative events.

Curiously, according to the shop I took my car to for a corner balance and alignment, I already had my 933 close as is when I dropped the car off. They didn't have to adjust much, if any. All I did was set the ride height to half way between RS and RoW Sport measured according to Porsche specs when installing PSS10s. Either luck or those Porsche ride height specifications and where to measure from mean something as far as starting points for a good corner balance.

nile13

The ride height from the factory should be fairly well corner balanced, I'd think. Corner balancing mostly concerns cross-weights (LF+RR vs. RF+LR). So if they have an assumption of a 180lb guy in a driver's seat of a LHD car they should be able to set corner balance pretty close to ideal.

Which would bring up a question on how RHD cars are set up in this respect.

solomonschris

Not to beat a dead horse, but it does not cost that much to do. It is not necessary to be in the car, just an approx. equal weight placed on the seat. Also, compared to the cost of tires and how short their life span, it didn't seem to me much of an extravagance. I'm no mechanic, but it would seem if you are switching to ROW ride height, you would want to do this in any case, no?

nile13

Can you clearly explain how corner balancing affected your tires? And how "switching to XXX ride height" makes any difference in this case?

We are not talking about alignment here. That is absolutely needed (at the very least your camber will change with height changes). But corner balancing?

Mark in Baltimore

Yup, I was wondering how corner balancing (or not) affects tire wear, too. I can't see how the difference of a hundred pounds or so on one corner can increase the load on a tire to the extent that wear significantly increases, but I am not an engineer.

il pirata

Changing ride height does effect corner balance.

From Elephant Racing (or any number of other sources):

"What is corner balance?

Corner balancing is the process of shifting the weight carried by each wheel to approach optimal values. Although some weight can be shifted between wheels by physically relocating parts of the car, the corner balance process is focused on shifting weight by adjusting the suspension spring height. Any relocation of parts should be performed before corner balancing begins.

Why corner balance?

A properly corner balanced car will handle evenly in left and right turns. Unbalanced handling occurs when front-to-rear weight distribution is not equal for left and right sides.

In a symmetric car out-of-balance is easily understood as excessive weight carried by one pair of diagonal wheels resulting in a teeter-totter affect. If the imbalance is extreme, one of the light wheels may be completely off the ground even at rest!

Street cars are rarely corner balanced and typically have no provision for adjusting spring height. That's because their spring rate is relatively low, perhaps 100 lbs/in. With such low spring rates it would take a huge imbalance in spring height to have a significant affect on corner balance.

Performance and race cars may have spring rates of 300, 400, 500 lbs/in and higher. Corner balance becomes much more important due to the high spring rates - small changes in height greatly impact weight carried. Additionally, we are much more concerned with handling and performance with race cars so corner balance becomes very important."

I would assume most 993s have shocks with higher spring rates although not all have adjustable shocks (maybe we should poll this!).

In any case if you are in there...it is incremental work...last time I had a full alignment and corner balance it was $350.

Back to the originally question...I would do a corner balance along with an alignment unless you know who has been monkeying around with the suspension the last 15 years...the car is most likely not balanced.

race911

And then that pesky detail of preload from the roll bars.

Funny you mention weight in the driver's seat for even a street alignment. I did, even back in the mid-'80s when I had my brand-spankin'-new Hunter C111. Just came from what I'd learned stringing up to do race cars.

As far as the actual utility of corner balancing, what did we use before platform scales? Common was a weight checker that hooked under a wheel, and you'd read a gauge showing you the force required to lift said tire off the ground. Yeah, reallllllllllly precise.

solomonschris

Where in my post did I say that corner balancing affected tire wear? What I did say is that we spend a lot of money on tires. There is an enormous number of posts concerning tires. Presumably, we spend this money to improve the car in the way we wish. This could be a better tire for road street in terms of ride quality, noise, tire life, wet performance etc. or track use or some combination. Considering the amount of money spent on tires, spending a much smaller amount on a corner balance to improve your car does not seem to me an
extravagance. If you believe it makes no difference so be it. I stated that since I had other work done at the same time, I didn't know what to attribute to tire balance. I'll try to be more clear in the future.

nile13

You are correct, you did not say specifically that tire wear was corner balance dependent. It's just bringing the tire wear/balance into the same sentence lead me to believe that you think it was.

If $300-400 is of no consequence, by all means, corner balance the street car. If it is (it is to me), I'd rather spend it on better tires or an extra alignment a year down the road, especially considering the road condition we are all driving on in Northeast.

nile13

That is cheaper than most, I believe. An alignment usually runs about $300 with proper kinematic adjustment tool (and it's a bit of an art. I've aligned cars before both with strings and plates as well as laser Hunter machines... it's not as trivial as it might seem).

If they are willing to drag out 4 proper scales, set them up correctly (scales are notoriously finicky and dependent on flatness of the ground and other factors), drive the car on, drive the car off, get it up in the air, take the wheels off, adjust height, put the wheels on, get the car down, drive it onto scales, lather, rinse, repeat at least 3-4 times until it's really properly set... all for $50... I'd marry the mechanic's daughter as she's from a really good family, apparently.

In short, I corner balance a 2100 lb autocross car (with 800/550 lb springs, pre-load taken out of the front bar, etc, etc). I don't corner balance street cars. But that's just a personal thing.