Help with corner balance

[mmasse]

I just bought a set of Longacre scales to use for corner balance.

I put the car on the scales (with myself on the driver seat) and this is what I got.



What do you think?

I was really expecting to see something wrong on the front size since when I hit the brakes strong the front left tire locks well in advance than the rest of the wheels, but the front seems to be well balanced.

I will appreciatte eny comments/suggestions.

Thanks

[Dixie]

Those numbers look pretty darn good. Did you weigh it on a level surface?

[mmasse]

YEs, my garage floor is pretty well leveled (not perfect, but..)

But what about the rear difference? isnt it too much?!?!

[Chuck Moreland]

Did you measure the surface to ensure it is level? Just looking at it isn't nearly good enough.

[911st]

Not and expert but here are some thoughts.

Wonder about the brakes. Is there any air in the line on the side that is not locking? Been rebuilt? Any ware issues on the rotors? Fresh brake lines...

Dose the floor have to be level or just flat? Could leave the scales in place and turn the car front to back and see if it reads the same.

Did you check that air pressure is balanced on fronts and rears for the test?

Are the sways disconnected for the test? If not, they could be transferring load from one side to the other and giving misleading information on the scales.

Is the alignment good, more neg camber on one side than the other could effect braking.

[mmasse]

I measure it with a bubble level and it seems ok. Today I turn the car around (front where the rear was) and I got very similar numbers.

So, my question is:

Is the 45KG difference between rear left and right relevant? or should I try to get them closer.

On the brakes, the brake lines are newon both side, and not, the calipers have not been rebuild for some time.

Thanks

[RWebb]

level AND flat - or (if you insist) the 4 spots where the tires sit need to be flat, level, and at the same level - you can have a Petit Canyon in between them if you want...

I would use a water level to check - what you did was just to measure a local area -- unless you have one hell of a long bubble level...

[dad911]

How low is the front? You may be hitting the bump stops under hard braking. I also had this problem (brake lockup) when I had a binding spot in one of the front struts.


You should use a laser, transit or water level to level the scales. Or a very good level(machinist?) with a long straightedge.

[rusnak]

hey nice setup! It would be cool to see more pics of the wheel scales.

I think you could have an issue with the right side caliper/rotor, which could be failing to generate enough pressure or friction. I'd check the caliper for leaking fluid or see if the pads or rotors have gotten wheel grease or oil on them.

[Jeff Alton]

It really does not matter if the front scales are higher/lower than the rear by a wee bit as long as they are even left to right..........


Cheers

[afterburn 549]

Numbers are good, check everything else sticky strut, stiction (suspension) , seized caliper...etc

[911st]

New brake lines you say!

I am not an expert but might try bleading them again, start with the farthest from the master first. I hear tapping the calipers to release any bubbles can be helpfull.

I like the front bump stop thought. Did not think of that one.

I would still suggest disconectting the sway bars to make sure they are not preloading in one direction that is offseting preload in the springs the other way. Sways transfer weight from one side to the other.

Even just disconecting one side of the rear would give some indication-- if it changes the weights much you are not trully corner ballanced. If this dose not effect the weights, you are in great condition. If it dose, disconect the front also and rebalance. Adjustable links are helpfull to ensure you do not get any preload from the sways.

If when the the car is fliped front to back the weights were the same, the scales are flat.

Level is just referance to achive flat. Non level is not going to effect weight unless it is signifficant like 20 deg or somthing.

Two taunt strings crossing at the same point in the middle could work as referance to achive flat.

[John Brandt]

Your corner weights look super and even if they're off by a fair amount they are not going to be doing what you've describe (to the extent that you're experiencing) I have had this precise scenario play out on my car recently and having been focused on corner weights, your mind will tell you that's the problem. What I would suggest is to Massage the pistons and see if that fixes you up. Remove one of your brake pads and have a helper push the pedal to move the piston out and then push back in a few times. Then repeat on the other piston, and then on the other caliper

[911s55]

Having front numbers that are only 5 lbs different is very good, achieving front weights that are matched is more important than the side to side totals. I wouldn't change them unless you have height or clearance issues.
Under braking the weight transfers to the front wheels, you will get even distibution on each front wheel, and that is good!

David

[TimT]

I would still suggest disconectting the sway bars

Always....Always disconnect the sway bars when corner balancing... you only need to disconnect one end.

I'm not sure whether you have coil-overs or not, but with those numbers you could have a well balanced car easily. If torsion bars, you can jack some weight around also..

My first pass would be to turn the ride height screw on the front left (drivers side) up.... i.e. raise the front left height a tad...

then drive the car, or jump all over the suspension and re-weigh...

You would be surprised how effective small changes are, especially if you have a low friction suspension...

[dfink]

First question is are you sitting the car or are those naked numbers. Unless you are planning remote control you must have your weight where it will be to get an accurate picture of where you are at.
As for weighting I have read get the diagonals the same, I have also heard it is more important to get the front weights the same. Personally I try for the diagonals.(never mind I just saw you said you were in the seat)

[Dixie]

My first pass would be to turn the ride height screw on the front left (drivers side) up....

On the other hand, I'd leave it alone. Having the front weight so evenly split will result in very stable braking. The numbers he has look great!

[911st]

I wonder if the equal front weight on front tires would remain that way when the brakes are aggressively applied and weight shifts forward.

Assuming pre-load is built into one side of the rear to achieve the balanced fronts.

My money is still on their being air in one of the brake lines from the brake line swap.

This is just an uneducated guess.

[mmasse]

Thanks a lot to everybody for all the inputs.

Bad news My car rolled off the scales and the inertial took it agains a column in my garage %·!$!/(·$&"" ...not big deal, but I have FG bumper and it would need repair!!

Back to the braking problem, I think rusnak might have found the reason. Some time ago, I installed an oil cooler on the passenger fender and during the test ride it had an oil leak. Oil wet the right front wheel and oil made its way to the brake pads. I dissasembled everything and cleaned with Brake cleaner extensivelly, but it seems that the pads could have been affected by that. I really do not recall if I had the braking issue before that. I have ordered new brake pads and will test as soon as I get them...and I will post the findings.


Thanks again

[Flieger]

Organic pads will get screwed up when in contact with oil. It can get into the pores and you'll never get it all out.

Good call on the new pads, rusnak