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Author Topic:   Ride heights?
24ksi Racing
Dirt Roller

Total posts: 13
posted September 25, 2000 10:10 AM
I am racing a GM Metric street stock on a very flat ľ mile dirt oval that is usually a very rough surface. Iím having a problem getting into the corner that I canít seem to solve. What happens is as I set the car in the corner, the back end starts to come around like it should, but if I carry as much speed as I need to the whole car (mainly the back) skates. Itís like a neutral skid, slightly on the loose side.

Itís got me stumped. I have scales and an alignment gage, and I know Iím in the ballpark. I have 49% rear, 53% left, and 50.5% cross with 3250 total weight. While I would like a higher rear percentage, Iíll need to put the front on the diet to get it done. The front end is set at LF 2.5 deg. pos camber and 2.5 positive caster, RF 4 deg neg camber and 4 positive caster. My springs are RF 1200, LF 1000, RR 250, LR 300.

The only thing that comes to my mind is either bad rear shocks or bottoming out. A trustworthy chassis guy at the track this past week asked me about the ride heights. Truthfully, Iíve never paid attention to them. Turns out they are RF 7-1/8Ē, LF 6-1/4Ē, RR 8Ē, LR 7Ē (measured at the main frame rail). He thought I was too low on the left and needed to get the car level. I checked my Steve Smith SS Chassis book, and he has all of two paragraphs on the subject.

Thus far, all Iíve paid attention to with ride heights is to make sure that the lower ball joints were at or below the inner pivot points of the a-frame. Then, at the rear that the lower control arms were about level (they are actually sloped down towards the front by about ĺĒ).

Got any ideas????

Thanks

Bill www.chasinracin.com/racers/24ksiracing

[This message has been edited by 24ksi Racing (edited September 25, 2000).]

ss38k
Dirt Roller

Total posts: 22
posted September 25, 2000 02:19 PM
i which i could help .but i will be keeping a eye on your ? because my ss monte is doing the same thing to me.i think what i did wrong . was that i put all my weight back with the fuel cell just moved it above the rear end. hope it work's now going to weigh it too night .first time for that. just got it done and went racing about 4 week's ago. good luck. which i could help you. my car also set's a 1"/1/4 lower on the driver's side. it go's like this.lf 7" lr 7" rf8"1/4 rr 8"1/4 let me know how you make out i will do the same ran 6 race this year going to run two more. going to run for rookie of the year 2001 again good luck

PEDDLER
Dirt Maniac

Total posts: 148
posted September 25, 2000 10:05 PM
Well here goes.
1. Try to set the car with the right rear as the highest point and the left front the lowest.
2.Get someone to tape the races and use a good vcr that you can advance frame by frame in order to watch the wheels and body roll.
3. Add lead if you can to the rear as to increase rear % but dont go overboard.

I always used a rule on chassis height in that the rt front and left rear were as close to the same as possible.
example:
lf 6 1/2 rf 7
lr 7 rr 7 1/2

Don't forget stagger gets you into a corner and wedge gets you off the corner.

Good luck, Race hard and clean for this is a hobby for most of us.

The Peddler

tightwad
Dirt Newbie

Total posts: 1
posted September 28, 2000 12:19 PM
generally; rougher tracks need softer springs. lighter rear percentages need softer springs &/or less stagger. stiff suspension makes the car "skate".

from my experiences, i agree you're in the ballpark. although i think you'd be happier with a 225 l.r. spring & 175 r.r., try your 250 on the l.r. and get a 200 for the r.r. and use one inch of stagger. if you like that result, go for the 225/175 combo.

you may notice more push on entry as you are able to corner harder. decreasing your cross percentage closer to 48% will cure that.
incerasing rear brake bias may also be called for.
softer tire pressures may be another possibility as well as a 900 l.f. spring depending on what else is happening.

have fun & good luck !

66skip
Dirt Roller

Total posts: 17
posted October 12, 2000 10:06 PM
We don,t run many short tracks ,but have had some of the same problems on the half miles. We softened our right front to 1100# and elevated our weight. Also we think our car is faster at 3600# and 54% tail than it ever was at 3280# and 50% tail. Sacrifice a little weight for some tail %.
GOOD LUCK !

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