1/4 mile car front end alignment

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swifter

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Car-67 Valiant with new: QA1 k-frame,QA1 lower arms,QA1 upper arms,New .810 MP torsion bars,New inner and outer tie rod ends,New spindles with strange disc drag brakes,New comp. eng adjustable shocks set at 90/10,New MT et front tires, so our goal was 0 degrees camber,6 degrees positive castor and 1/16 toe in ,We purchased the fasttrax castor/camber gauges to do alignment,Out of all the reading I did on the subject with drag car front ends I came to conclusion to align the car at "track attitude" meaning the front end is lifted thru out the run,After watching video's on the car we set the car at what we thought the height should be and proceeded to align the front end and we met out requirements but here is the rub we have,When the car is set back down and not at run height we get 2 degrees of negative camber with the weight on the front end???? is this normal??? as soon as we load the chassis it goes right to what we want at--o degrees camber-6 degrees castor and out 1/16 toe in,So were kinda confused cause this is our first time doing this and are learning--Thanks Steve
 
Jack the front end off the ground, if the top of the tire kicks in, add some negative (?) Camber to compensate.

I might have my old notes, been awhile since I messed with it
 
Not really a bother just asked the pro's if this is normal-Thanks Steve
 
biggest question...does the car track straight or are you constantly chasing it?
 
Not really bothered more or less asking if this is normal cause it's out first go around with front end stuff,Dylan when we do that it's absolutely perfect,I just want to make sure its all good,Went to track today and as we got there they closed it down (rain was coming) so we'll try again Thursday--Steve
 
Tony,Haven't had it out yet,We tried today but the rain moved in so I can't answer that till thursday I hope---Steve
 
I would say it is a "normal" function. The UCA and LCA swing in different arcs simply because they are not equal lengths. The more suspension travel, the greater the camber change.

From my limited knowledge, I think you are right on track with setting up your suspension at the track/race attitude.

It is like the caster setting, going for stability at higher speeds instead of easy turning into the driveway.


Good luck!
Denny
 
It seems good to me. Good plan for setting it up for on track. If you were to drive it on the street often, you would just wear the inside of the tire faster. If you like the way it handles on track, then I would leave it. A friends 68 Dart is leaned in more than that I would say from the look of his car. Got any pics of static height and race height??
 
Yes bob we raised it up about a inch-thanks for chiming in, your advice is golden-steve
 
75DartSE said:
It seems good to me. Good plan for setting it up for on track. If you were to drive it on the street often, you would just wear the inside of the tire faster. If you like the way it handles on track, then I would leave it. A friends 68 Dart is leaned in more than that I would say from the look of his car. Got any pics of static height and race height??
Click to expand...

I set mine up for the track, and yes it does wear out the inside of the front tire quickly on the street...but not too badly. I have had the same front tires on the car for about 10 years, and I'm thinking I will probably replace them in the next year or so due to wear.

If you are interested, I found these picks of my car from the Goodguys race that show the static stance versus under power. If you notice, when the car is at rest the front tires are tipped in a little, but under power they are straight up and down. I don't know if it is right or wrong, but my car works well like this and handles well at high speed.

Sitting still:
http://www.smugmug.com/gallery/n-L5ZqM/i-4X6fQj8/A

Under power:
http://www.smugmug.com/gallery/n-L5ZqM/i-JfBvrcp/A
 
Fly-That is EXACTLY what our wheels look like static !!!!! Thant helped immensely,Hopefully we will have video's tomorrow night if the rain holds off,Thanks for all the help guy's,I hope this will help others too--Steve
 
Fly if you look real close and switch between the two pics your raising the front about 3 to 4 in on green--Steve
 
if memory serves....even a street car alignment "should be" around 1" above static because (at least our old rides) the car actually is at about 1" joyce when just powering down the road.

if you have a fairly low static height....and are using a shock that has a lot of compression dampning that holds the front end up, like a 90/10 (compression / rebound) ....then you might want to consider adding an additional inch or so, to the additional inch above static you are already have for a drag racing alignment.

you could have someone film or snap a picture the car at throttle at the big end and see how high the nose is....that is where (in my opinion) that race alignment gets the biggest advantage.

good luck,
Denny

spec the camber at 0*......not much road crown to worry about on the drag strip
 
The best thing to do is get video of the car about 1/3 track right after the front end has settled to where it will carry. Note the space between the front fender and tire and duplicate that height on the alignment machine. That way, the alignment will be correct with the car at speed instead of static, which is what you want. As for specs, I would start with the stock specs, but with the front end raised as described and work from there.
 
Thanks Rusty-Well went to track and it wasn't good,Car was all over the track and zach did a great job of lifting his foot and gently correcting the car,I know we have to take into account track prep was null and void because of test and tune night and the fact that guy's brought there own vht to spray on the launch pad BUT the car was horrible and thats on me so I need some advice on chassis set up,We got scales finally on friday (back ordered from jegs)and set the car on them,so we have 761 lbs on the front left,804 lbs on the front right,822 lbs on the back left,668 lbs on the back right SO we need to get the weight on the RR instead of the LR and I don't know what we want as far as front to back %-How do we move the weight to the right back and off the left back?? I know there is something about diagonal weight too and we are at a loss so help would be much appreciated--Steve
 
Sorry--car has single adjustable strange coil overs on back,we don't know what weight the springs are for them,also car is a ladder bar car---Steve
 
Turn in some spring preload on the lighter corners which are opposite and remove equal amounts on the heavier corners. Start with maybe a turn on the coilovers and I'm guessing you have torsion bars? Try a turn on the bolt at a time and see what the weights do. All this with full race weight of course. If you always adjust all 4 corners the. The car should always sit level and the opposite corners will transfer weight.
 
the bump steer can cause this change. i have 0 camber and 6 degrees of caster the toe stays the same from ride height to 4 inch up, i put adjustable heim joints on each end of the tie rods to correct alot of bump steer
 
what type of rear suspension is on the car? Leaf, ladder bar or 4-link. Ladder bar or 4-link weight can be changed very easy. Just add/remove pre-load by turning the adjuster and watching the scales. [be sure weight is in the driver seat which is equal to the driver...or the driver himself!]
 
ladder bar rob,We finally conquered the front end,We took the car to a frame shop and the car is twisted 3/8 not a big surprise and we will straighten it next winter,Once we compensated for this with weight adjustment we are golden lol at the moment,Car is straight as a arrow now and Zach just has to do hie part to be more consistent which comes from seat time,Thanks Guy's
 
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