patd

Weighed the car at the track the other day with me in it. Here's the results:

LF 960 RF 795
LR 825 RR 888

How can I even this out? <img src="confused.gif" border="0">

IanM

I suppose you'd raise the front left corner a touch, and maybe lower the front right a touch. Do you have M030 coilovers? They're awfully handy. You should also make sure you don't have some preload set into your front swaybars, in particular the left side.

txhedg

[quote]How can I even this out? <hr></blockquote>

Slide your seat back and always take a passenger

FYI, mine with driver and 1/2 tank gas was:

LF 740 RF 715
LR 742 RR 615

with driver: 2812
without driver: 2518

you can do the math on how fat my **** is


- I'm getting punchy I think its time for me to go home for the weekend

patd

I do have M030 but how do I know if there is any preload on the bar?

quote:
you can do the math on how......


Looks like we are a matched set!

Danno

[quote]I suppose you'd raise the front left corner a touch, and maybe lower the front right a touch.<hr></blockquote>Hmm... if anything, it's the opposite. You'd want to lower the Left-Front to take load off it (and transfer to Right-Front and Left-Rear). First, let's review the basics of corner-weighting a car: <a href="http://forums.rennlist.com/scripts/rennforums/ultimatebb.cgi?ubb=get_topic&f=10&t=000146" target="_blank">Corner Weights (RS/RSR)???</a>

Why would lowering a corner remove weight from it? Well, go back to my teeter-tottering table in the previous thread, or let's use another example. Imagine you've got four guys carrying your car with the tires on their heads. And let's say the guy under the LF tire suddenly falls into a pothole. what happens to the weight on the other guys? Well, it lightens up for the RR guy because the car would rock a little down towards the LF and pick up the RR. And the RF and LR would have to take up the slack because their heads would be the tallest ones on that plane. Only if the RF and LR guys duck down to the level of the LF guy in the pothole will their loads be lightened. And then the tallest one, the RR would end up taking a higher load because he's the tallest now. So the general rule in corner-weighting is lowering a corner lightens the load on that wheel along with the diagonal opposite one, while increasing the load on the two adjacent tires.

So what we really want to do is even out the cross-diagonal sums of the weights to give the most even loading of all the tires. We can never get even left-right distributions because of the driver. The existing cross-diagonal sums now are:

• LF + RR = 1848 lbs
• RF + LR = 1620 lbs

Given your total weight of 3468 lbs, this is a diagonal distribution of 53.2/46.7 or 6.5% difference.


To remove any preload on from the swaybars, disconnect them completely before your corner-weighing session (tie them up against the body with some string). After the corner-weight session re-install them, drive around for a bit and re-check the corner-weights, they should be the same. If not, you've got some uneven swaybar loading at resting ride-height.

Now to even out the cross-diagonal weights on your car, you'd need to lighten up the front left and transfer some of that weight to the RF and LR. This can be done either by lowering the LR or RR. If you don't have front coilovers, you can just lower the RR by 1/4" and see what the resulting balance is. Most likely, you'll end up with something like this:

• LF 910 RF 830
• LR 870 RR 858

which works out to a diagonal cross-balance of:

• LF + RR = 1768 lbs
• RF + LR = 1700lbs

for a distribution of 50.98/49.02 or 1.97% difference.


But more impotantly, you can see that you've lightened up the two most heavily weighted tires, and distributed their extra weights to the other two lightly loaded tires with a single adjustment.