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Author Topic:   Front end help needed !
racecar
Member
posted June 05, 2002 07:50 PM
Brand new 4-bar metric clip modified. The car is totally undriveable it darts side to side going down the straights and it feels like someone is jerking on the steering wheel through the corners. The car is actually dangerous because it drives so bad. Any thoughts or suggestions would be greatly appreciated.


crash1x
Member
posted June 05, 2002 08:58 PM
where is toe at toe in can make the car dart
and very hard to drive.


race8k
Member
posted June 06, 2002 10:11 AM
do you know what the front end settings are now.Post them here and maybe I can help.


smayo964
Member
posted June 06, 2002 10:19 AM
Yeah Crash, I agree with the toe or either his caster settings are way off. Even though the car is new, what's the odds of the steering box being bad?


HONDO
Member
posted June 06, 2002 05:21 PM
I test drove a camaro for a guy once that did this. It darted all over the place as soon as you hit a bump or wen't through a corner. I looked it over after the main and found out the guy had put the upper A arms on the wrong sides. It was his first year racing and he got a car with no upper arms on it. Anyway my theory was that the caster was ok staticly but dynamicly it was going through a curve that was terrible. Anyway, I would be looking at caster.


racecar
Member
posted June 06, 2002 06:47 PM
Front end settings are caster lf +.5, rf +4.5
camber lf +1.5 rf -3 . toe is 1/8 out. have not checked bump steer. thanks in advance


Wheels47
Member
posted June 06, 2002 08:02 PM
Racecar. In looking at your camber settings, I'm wondering on the LF setting. First, what air pressure are you running on the fronts? I'll leave this open for comments, but do you possibly have a "lack of" contact patch with running positive camber on the left? Anyone? Granted, the right should be laid in for handling the banking/turning. On comment on the caster settings. With the amount of split you are running, the car should be pulling hard left naturally down the straights. When you turn that wheel right to compensate any cornering your are going to tighten the car by applying cross weight to the left rear. The more caster on the right, the more cross. You might want to consider maybe leaving the right alone and increasing the left a bit to narrow the split to about 3 deg difference and see how that works. Just a thought.


race8k
Member
posted June 07, 2002 02:41 PM
That is exactly what I would do.


uforacing51
Member
posted June 08, 2002 12:09 AM
Check all the parts in the front end, seems like even if some of the stuff was out of adjustment it wouldn't dart that bad. make sure all you components are in good repair. Start over so to speak, call the factory too.
I wouldn't think it would come from the factory like that.

[This message has been edited by uforacing51 (edited June 08, 2002).]

racecar
Member
posted June 11, 2002 09:11 PM
I re-did the entire front end this past week with all gm spindles and made sure the caster camber and bump were correct and within the parameters I have ran in the past. Within 12 laps my arms were completely numb from trying to control the car. It seems as if the car rolls down and over on the right front and never comes back off of it no matter what spring rate is on that corner. It is obvious that my front end geometry is really off and the only difference in the front from this car to last years car is the upper control arms. I had my chassis builder install adjustable tubes with heims for uppers. What is the chance that my anti-dive is really ******* up? and how do I check it?


jlfastride
Member
posted June 12, 2002 11:19 PM
what about you panhard bar angle?????????? to much will cause this too. i watch a guy at our track and for the last 3 years he's hardly finished a race because the car rolls over so hard and erratically that it's unpredictable to the drive and the ones around him in traffic.


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