Mike Buck

$310 is a reasonable price if the shop is good. Who quoted you that?

Oddjob

Corner balancing is adjusting the weight on each wheel (this is done by changing ride height) so that the diagonal weights are approximately equal (RF + LR = LF + RR). This is done mainly on track cars.

Think of it like a 4 legged table in a bar, that needs beer coasters under one leg so it wont wobble - the 4 wheels of the car are a similar concept, if the heights are messed up, the car will have more weight on certain corners. If you adjust the height of the suspension, you can get the weight to balance (like table legs that have the threaded feet/castors).

Since front to rear weight distribution is not exactly equal (especially in a 911), all 4 corner weights will not be equal, which is why the balancing is done by making the diagonal weights equal. Very simplistic explanation, but hopefully gives a basic concept.

Mike is correct, $310 is actually cheap for an alignment and corner balance, Im used to seeing $450+. But I agree with Vaughan that it is unnecessary for a street car, so its a waste of $ over just a standard alignment, which should be in the $150 ballpark for a p-car shop.

Also, on a stock 944/951 with non-ride height adjustable perches, all the corner balancing must be done using only the rear spring plate height adjustment eccentrics - which is far from ideal. I dont think I would mess with corner balancing unless I had at least the factory M030 adj. front struts, or full coil over suspension.

smlporsche

Just curious, how close should a good shop get the diagonal corners to be to eachother assuming adjustable coiloveers on all 4 corners for a track car ??

Oddjob

I would be pretty happy if my diagonal numbers were within 20-30 lbs of each other.

Also, you have to assume that the scales are only accurate within a % or two. So for example, 2% of 700 lbs per corner is approx 14lbs possible error. Any changes/differences within that margin of error are pretty much meaningless.

If you have some real trick scales (ie: expensive), then you can likely get a tighter/accurate balance - but its nothing that you would notice by seat of the pants feel or by lap time improvement, so probably not worth the extra time/labor messing around with the ride height adjustments to get the difference that close to zero.

M758

When I personally corner balacned the car this summer I gave up at 50.4 and 49.6 or something.

My car was corner balanced by Chris Cervelli of Technodyne many years ago.

Cross weights were 50.02 and 49.98 or something like that.

azmi951

I had the wonderful oppertunity to corner ballnce my car at school in our Chassis lab (Kettering University) on a steel bedplate. I was "measuring for my chassis dynamics class." I have the Paragon coil overs on the front and after getting the corner withgts within .01% the car felt so much better. It was far less rocky feeling (like the uneven bar table analogy) and it was WAY off before.

The corner ballance combined with a good alignment makes this car feel so much better.

So make your own judgement. but if you have ever removed/replaced suspension in the car I feel it is a necessity.

dnwong

$310 was from Currys Auto