camber

coyled · #1 (**permalink**) 03-27-2003, 11:29 AM

The rear slicks have been wearing more on the inside edges(about 3 inches) than the rest of the tire. They have always done this. Do I care or should I just pay attention to tire temperatures and forget it? The temps are usually 15 degrees hotter on the inside than the middle and outside which are close to equal. The rear camber is at just over 1 degree negative. On acceleration, I know it gets even more negative camber do to the geometry of the trailing arms as the rear end squats. The fronts have 1.5 degrees negative and are 10 to 15 degrees hotter on the inside also but tire wear is even. Comments? scott.

KobraKarl · #2 (**permalink**) 03-27-2003, 11:34 AM

Who makes the Broker? and why would you want a stock one?

Excaliber · #3 (**permalink**) 03-27-2003, 11:44 AM

LOL,,,,,good question KobraKarl.
Them brokers come with small blocks mostly?

Actually you SHOULD pay attention to the tire temps and it's telling you "to much camber" by your heat readings. The ideal temp readings are even across the the tire. That says your getting the "full foot print" on the ground (critical for max traction and tire wear).

Ernie

coyled · #4 (**permalink**) 03-27-2003, 12:35 PM

I thourht that 10 to 15 degrees hotter on the inside was normal do to what you would see under acceleration and braking. Bias ply slick also, if that matters. I am concerned with race track cornering, not tire wear. Scott

Randy Rosenberg · #5 (**permalink**) 03-27-2003, 12:44 PM

How are you measuring the tire temps? Are you using a probe or IR pyrometer?

I ask, 'cause I've been reading up on this subject, and it seemed to fit in with this conversation...

http://www.longacreracing.com/articles/art.asp?artid=16

Thanks,
Randy R...

coyled · #6 (**permalink**) 03-27-2003, 02:15 PM

I saw the sight. Its with a probe. scott

CSX 4027 · #7 (**permalink**) 03-27-2003, 03:47 PM

Try 1/2 to 0 camber in the rear and check the tire temps again. Remember, when the rear squats you will get addt'l neg camber. The amount of squat will be determined by your springs, stabilizer and shocks. Get the tire temps right and your done at least for now.

Richard Hudgins · #8 (**permalink**) 03-27-2003, 08:30 PM

Hi Scott,

If I were you, I would measure the pickup points for your suspension, both front and rear and plot the camber curves. This will give you a good baseline to determine static settings. (1 degree negative in the rear sounds high to me as a static setting.)

Also, I recommend that you get on a skidpad. Steady state cornering will give you much better temp readings than at a track. Just do 5 or 6 laps on the pad and check temps. This will give you very good info about your camber settings and guide you to optimum camber setting for cornering.

After you have this sorted out, you can than start on damper rates.

I hate to tell you this, but per our conversations, you need to work on the damper rates.

It is obvious that your bump settings in the rear are too soft. (Your front rebound settings could also be too soft.) I think that a good part of your rear tire wear and tire temp is a result of too rapid squat under acceleration.

coyled · #9 (**permalink**) 03-28-2003, 10:05 AM

Richard, If you plot your camber curve, how do tyou know how much squat you are getting other than a visual guess? I know that if you jack the back end up an inch, the toe change is close to an 1/8 inch in. I am assuming on squat it goes the other way an 1/8 inch, which is why I run 3/16 in. static. At 1/16 inch in, it use to hunt in back, drove me crazy.I just got the shocks back from the gooru's at pro shocks, sure to make the driver better(wink,wink). We did go up in rebound in the fronts. There is an inch or 2 of squat under acceleration, which will cause even more negative camber than static. I know what you are saying about a skid pad. Most corners, I am accelerating, not much steady state accept for intitial turn in. I think that I can take some out as it will still go negative when I need it most(corner exit) and I may get better tractioin comeing out of the corner. Maybe better straight line brakes also. Thanks, scott

Richard Hudgins · #10 (**permalink**) 03-28-2003, 07:53 PM

Scott,

One good way to measure squat is to put a ty-rap around the damper shaft so that it touches the top of the damper body at ride height. Then drive the car on a smooth bit of road and jump on it.

Then measure the amount of movement of the ty-rap. This will give you the amount of squat that you have. (At the damper, you will have to look at the motion ratios to extrapolate wheel movement.)

I am not familar with your chassis, but that is a bunch of toe steer. Are you sure this cannot be adjusted out? Rear toe steer is not good. Makes it damned near impossible to set up the chassis so that it feels good to the driver. Plus 3/16 in is giving you a bunch of drag.

I would look at fixing the toe steer before I worried about anything else.

Also, It is proven fact (Just ask any driver) that new dampers improve the driver far more than the cost involved of the new units. Just ask any damper supplier and they will confirm these findings.