wheel base and square rear end

[sparkyboyd]

   love this sight, my question is, I have two set up books and am trying to change my wheel base. my right sides is 72 3/4 and my left is 73 1/4 I would like to chang to even or shorter on left side by 1/4. all the books talk about squaring the rear end, and then they say to change your wheel base adjust lower control bar in rear... If I am square and I change this would'nt my rear end be out?  Thanks you     -Brian

[Winterracing]

what we do is bring both trailing arms in the rear about an equal amount up and then resquare it, recheck the wheelbase, if it needs to get shorter then continue this until you get what you want.  Then check the pinion angle as it might change.  Also make sure your front end is all set before checking the wheel base because caster and camber being off will affect it.

Dan
www.winterracing.net

[VMS Motorsports]

Any of the 4 bars in the rear can change/affect your rear end being square.
First off, don't worry about wheelbase being equal on each side, I think the best idea is to make sure the rear end is square, wheel base is an afterthought, as long as you're within the rules.

[Winterracing]

Any of the 4 bars in the rear can change/affect your rear end being square.
First off, don't worry about wheelbase being equal on each side, I think the best idea is to make sure the rear end is square, wheel base is an afterthought, as long as you're within the rules.

My problem at first was getting within the rules.  But since we worked on it a little i'm alright, i think i read you want 1/8" to 3/16" difference on both sides

Dan
www.winterracing.net

[knoxracing]

To answer your question. You do not want to adjust the rear if it is square unless you have to. My suggestion is pull the left front back a 1/4 inch, and its simple. Turn the heim joint that attaches the lower a-arm to the frame in about four full turns, then turn the caster bar in two full turns. You are turning the lowere heim 4 turns. This will keep all the front end settings the same (caster, camber) while pulling the left front wheel back a 1/4 inch, check your toe and remeasure wheel base, you will be good.

[sparkyboyd]

  Thanks everbody. im kinda new to this so your never sure exactly how you should do it. This gives me some great ideas...Thank you

[JGRacing]

Do some searches around the site and you will find good information on different methods of measuring wheelbase and squaring the car. 

[DoubleZero]

Good discussion guys.  I'm very new to Legends so this is helpful.  Just a question.  Was it a typo when you said turn the lower A-arm in four turns and the upper caster bar in TWO turns?  I would think you would turn both the upper and lower the same number of turns.  Otherwise, wouldn't you chage the caster setting?  Thanks.

[knoxracing]

No typo, no no no! The lower heim that attaches to the chassis, would be a single heim joint. You can lengthen or shorten it to adjust wheel base. The second adjustment must be done with the cast BAR, this adjustment will be done by turning the bar, this will be turning TWO heim joints as you twist the bar. This is why the lower adjustment is twice the turns, it involves one heim. The upeer involves two heims, you are turning the bar in or out. I hope you get this, kind of hard for me to explain. This is so simple to do at the track also, you can change the car quite a bit with whell base adjustments. Your caster camber will be basically unchanged, I suggest you double check the wheel base and toe. I set toe with the wheel base gauge, so its really simple to make adjustments at the track and be pretty accurate.

[DoubleZero]

Thanks.  That response saved me some future headaches for sure!  Really appreciate the help.

[IraceLegends77]

I too was a little confused on what Dennis was saying. If you loosen both ends of the upper then it would be half of the bottom. I uselly only loosen one end so it would be 1-1 on the turns then. I guess I'm thinking right?