RF Caster Setup problem

[knuclebuster]

Hey Guys,
  What do you do when your trying to set RF caster and the shortest take up on the rod only gives you zero degree caster?  I have the LF set at positive 2 degrees.  I was attempting to move the wheel back towards the firewall to positive 3 degrees, but all I can get to is zero.  Do you have to cut the rod and put the heim back in?  Also, when I set the left side caster to +2, when I turn the wheel to the left, which brings the back of the tire towards the header, the wheel rubs the fender.  Is this normal, looks like I may need to sand the fender back.  What do you think?

KB

[VMS Motorsports]

What length rod are you using?

[knuclebuster]

Jim, Im not sure.  When I get home today, I'll measure it to see.  My guess is that it is 12".

KB

[DanH]

Just go to an 11" rod will give you that bit less distance that you need. Not sure whats on my car now but im quite sure its an 11".

[VMS Motorsports]

Yep...what he said.

[RickyBobby]

also, don't forget that pulling your caster back will shorten your wheelbase, so you will have to go back and reset that.

[DanH]

Sounds like hes not running oval anyway so thats the last thing thats going to concern him as he can push both back.

Does make me think though why he got it to work one side and not the other.

@knucklebuster

Are your bottom arms set the same?

[RickyBobby]

It could have different sized spacers on each side.  Also the lower arm may be adjusted in too much.  You can gain some caster with adjusting both the top and bottom.

[knuclebuster]

Guys,
 Thanks for the replies.  As soon as I get home from work Im going to look over the different things you have mentioned.  I am running a high bank oval, 12 degree bank and 6 degree straights.

KB

[knuclebuster]

Well I was hoping that the answer to my caster problem was going to be the eleven inch rod.  Turns out, after stopping on the way home and picking up two eleven inch rods, that I already have eleven inch rods on the car.

Back to the drawing board.  Tell me what you guys know about caster and how important it is in your opinion.  My car is new.  I have not made any adjustments to the car other than beginning to set caster when I ran into problems.  I was using an average of what I read in Dwarf Technology book and a set up that came from the forum link as a basic ,getting started, paved oval track setup.  I was shooting for a LF +1 degree and RF +2 degree, but ran out of takeup on the RF at zero degrees and my tire is rubbing on the left side.

I am using a longacre guage and following the directions to get my reading.  Do you guys have any thoughts or advice to help me move forward on the setup.

Also, my RF camber is at -4 degrees.

Thanks,
KB

[elimn8u_43]

Check the spacers on the lower control arms where they bolt to the front crossmember. Make sure that the lower control arms are about an 1/16th  inch from the  front crossmember when the suspension is moved through it's full travel with the shock removed. Also check the spacers on the upper control arms where they bolt to the crossmember.  Hope this helps.

Geoff

[RickyBobby]

Also if the top rod has been pulled back all the way you get disconnect the lower control arm and turn the heim a few tums to get the Caster angle there.

[Racinjj]

I would lengthen out the rear heim on the lower a-arm.  Then use the top to tune it back in but remember to check wheel base.  From what I noticed when setting up my three cars it doesnt take much to go  a long way in the caster department.

[knuclebuster]

Ok, Guys thanks for all the info!  Came home from work and got busy checking a few things.  First, I marked off the tire contact areas for all four tires.  Rolled the car back and took a transeit and shot the grade of each of the four contact spots.  I found almost a 1/4" difference from the left side to the right side, just in the concrete.  My floor is anything but level.  Rolled the car back in and placed a 1/4" shim under the RF.  This changed up my set up numbers.  I was able to make the corrections and get the caster where I wanted it.  I got my caster and camber setups where I was trying to get to without too much trouble after getting the car level.  Also, before I did any setup changes, I also made sure the tire pressures were correct, which were also kinda all over the place.

So, in the end, Ive got a starting point anyway.  I appreciate eveyones willingness to give their opinion's on this topic.  Thanks again.  Hopefully headed to the track tommorrow to get some seat time for the first time since I bought the car last October.  Wish me luck to keep it off the wall!

KB

[VMS Motorsports]

Enjoy your seat time...sure would be nice to get some up here!