How the WRONG LINE COSTS YOU TIME

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The correct line is the fastest way through an autocross course. The wrong line will cost you time. This video uses an overhead view of a course to provide basic examples of how GOING WIDE, GETTING LATE, and ADDING UNNECESSARY INPUTS will cost you time out on course.


If you have any questions, please ask here or in the comments on YouTube. I’m always happy to help.
 

ttocs

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now I would LOVE to see one of these for a dirt track racer. I am always amazed how the different lines for those guys work out.
 

tvsn95

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The correct line is the fastest way through an autocross course. The wrong line will cost you time. This video uses an overhead view of a course to provide basic examples of how GOING WIDE, GETTING LATE, and ADDING UNNECESSARY INPUTS will cost you time out on course.


If you have any questions, please ask here or in the comments on YouTube. I’m always happy to help.
I like reading your comments and suggestions and if you can suffer a simple question I would be most grateful.
My SN95 is a 94 Cobra. its modifications are Single turbo (HP) detuned to about 690hp. T56 Mag trans, subframe connectors ( welded in) Koni shocks/struts new quad stocks, Torson diff w/308 gears, Nitto NTO5 drag radials R type on rear. It weighs 3600lb with me in it. The turbo required that the stock front sway bar be lowered 1 1/4" ride height is stock, the rear bar is replaced with an adjustable Eibach due to stock breakage several times, the upper control arms are adjustable, the lowers are ? aftermarket tubulars with urethane bushings. I have the aliment set @ 2-1/2 caster and 0 camber . Toe is 1/16 there and about.
Now, what happens is a sudden oversteer on turns at speed, normally requiring a minor reverse correction. very un-nerving at times. Car track well and I just can't put my finger on what the heck is causing it. believe me I have been looking. feels a lot like a low tire??? any thoughts
 
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Sudden oversteer can be setup-induced or driver-induced. One can also play into the other. Are your shocks and struts adjustable? Is your adjustable rear sway bar set to the stiffest setting? Are the bushings in your upper and lower control arms 3-piece poly or 2-piece poly? 3-piece poly bushings on the chassis side can help with nervousness at the limit of traction. Also, spherical upper differential housing bushings will add composure.

It sounds like you've set the car up for drag racing. Your caster and camber settings aren't ideal for handling. You want as much caster and as much negative camber as you can get (taking into consideration tire wear).

If your rear shocks are adjustable, try softening them up a bit. Or try softening the rear sway bar. It is also possible that the timing of your throttle inputs in the turn could be causing the oversteer.
 

tvsn95

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Sudden oversteer can be setup-induced or driver-induced. One can also play into the other. Are your shocks and struts adjustable? Is your adjustable rear sway bar set to the stiffest setting? Are the bushings in your upper and lower control arms 3-piece poly or 2-piece poly? 3-piece poly bushings on the chassis side can help with nervousness at the limit of traction. Also, spherical upper differential housing bushings will add composure.

It sounds like you've set the car up for drag racing. Your caster and camber settings aren't ideal for handling. You want as much caster and as much negative camber as you can get (taking into consideration tire wear).

If your rear shocks are adjustable, try softening them up a bit. Or try softening the rear sway bar. It is also possible that the timing of your throttle inputs in the turn could be causing the oversteer.
thanks for the input.
All the poly bushings are 2 piece, I will set the rear bar loose and try that.
during gradual steering input it twitches, as if something is in a bind them moves.
will play with it some more. thxs
 

tvsn95

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thanks for the input.
All the poly bushings are 2 piece, I will set the rear bar loose and try that.
during gradual steering input it twitches, as if something is in a bind them moves.
will play with it some more. thxs
what would you recommend for steering alinement ?
 
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thanks for the input.
All the poly bushings are 2 piece, I will set the rear bar loose and try that.
during gradual steering input it twitches, as if something is in a bind them moves.
will play with it some more. thxs
I'm always happy to help. It suspect the UCA and upper differential housing bushings could be the cause. When you adjust the rear sway bar, check those bushings for signs of wear/age.
 
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what would you recommend for steering alinement ?
My cars are only used for autocross, so their alignment specs give them a tendency to dart a little on the street. If your car is mostly used on the street, you might want to consider different settings.

And, to be as accurate as possible, the only SRA car I have (Fox Body) is camber limited due to the 96-04 spindles I used for the Cobra brake conversion. I can only get -1.3 degrees of camber up front. I also use forward-offset bushings to get more caster.

For a SRA autocross car, I would aim for -2.5 degrees of camber, as much caster as you can get (this varies with mods), and 1/16 toe out.

But, before you get another alignment, I would make sure you have the rear end issue solved.
 

tvsn95

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My cars are only used for autocross, so their alignment specs give them a tendency to dart a little on the street. If your car is mostly used on the street, you might want to consider different settings.

And, to be as accurate as possible, the only SRA car I have (Fox Body) is camber limited due to the 96-04 spindles I used for the Cobra brake conversion. I can only get -1.3 degrees of camber up front. I also use forward-offset bushings to get more caster.

For a SRA autocross car, I would aim for -2.5 degrees of camber, as much caster as you can get (this varies with mods), and 1/16 toe out.

But, before you get another alignment, I would make sure you have the rear end issue solved.
thanks I am on a new mission LOL
 

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