Wheels up launch, adjustment question

As you can see in the picture, the left front lifts quite a bit more than the right front and this a ladder bar setup.. What is the best or easiest way to pick them both up equally?

When this pic was taken, the car hit the driverside wheelie bar harder than the passenger side and the passenger side, did touch, but barely, it left a very small chalk mark and the car pulled hard right...

Whats your recommendations?

Try a quarter turn of pre-load, right side Don.

That seems easy enough... Thanks Dave

Put a anti roll bar on it... your system
is flexing

Good call Mike. Marcus had the same issue Don and his Charger was turning left a little as well. The little pre-load solved it on his ladder bar but the car looked slightly jacked on that side sitting still.

I knew an anti-roll bar would solve the problem, but wanted to see if there was another fix... I know if I ask Alguire, he would say "race on the stop... problem solved"...

Which leads me to yesterday's events at Sonoma.. In Vegas, the best I could muster was 9.0x in their 4500 DA air... Sonoma was awesome air yesterday, which my ET predictor had me dialed in for an 8.6x... I sooo wanted to run it all out just to get that 8.60 time slip... but I promised myself that I need the experience of setting the car up for S/ST racing... So all day was designed to figure out the numbers to put in the box

But it didnt matter as the car broke before I could even get to tech... So yesterday was a scratch

Dammit! What happened now???

Even with the anti roll it will help plant both
tires better.. better for you in any racing..
you cant have flex and be consistent.... what did
you break

I think my car is teaching me the finer points of patience and tolerance...

Dude! You must be a patron Saint by now...Sheeesh!

Looks like a little more air is needed in the rear tires

He needs to put the anti roll on first then see
about air.. its loading the RR harder due to twisting..
if it applies equal load to both tires it might be fine

8.5 lbs in both tires

Depending on the weight and tire size you would
be in the ball park

I said more air in tire. because it looks to me like too much. wrinkle ..I run 13+ on my car...these are heavy cars...talking to Al in Vegas he recommended that I try more air

I run driver side bAR 1in inch higher than passenger

If the car applies the load equally they wouldnt
need 2 different pressures.. they would be working
together.. but you can do what you want to

just things that I would try it wouldn't cost money.no anti roll bar here

You dont have the flex so the bar isnt needed..
a couple of things are happening on his.. the body
is rolling over to the RR and the axle is trying
to go up into the fender well.. its trying to roll
the axle over on the left rear.. if the body set
level on the launch both tires would work together..
I dont put a 4-link in a car without the anti roll
due to all the heims involved
EDIT
if it was going right before the bar hit.. put
some pre load in it(more down pressure on th RR)

First off get a set of scales and scale the car before you touch anything. More than likely you are light on the right rear side of the car causing the slight body roll and driving right.Once the rear is set properly it will leave straight and pick up both wheels evenly. You Dont need an anti rollbar.

just about everyone would benefit from an anti-roll

I dont agree. Set up the chassis right and it will not be needed.

I assume you dont put them on 4 links either

Go ahead and add some pre load.. thats a
quick and easy try.. it will help it from
turning right.. but IMO it wont correct the
roll onto the RR tire.. but try the pre load
and get back later

having scaled my car and noting how much slight adjustments change things I'm surprised at the "throw a 1/4 turn at it" recommendation.... and I'm by no means a seasoned pro at this stuff. Maybe this is coming from folks a lot more comfortable at these "adjustments" than I was.

I used to think that when they were first starting to show up and were considered exotic. Now, I wouldn't put one together without it. Another tuning tool in the toolbox.

And I agree on the scales. If you don't know where the weight is, you're guessing with your eyes closed. Bad springs and broken parts will show up on the scales. At a minimum, use the scales to verify that stuff is OK and baseline the car. Then go to the track and it will tell you what it wants.

This is recordings of the car before I did the coil over strut conversion.. Havent had the opportunity to scale it afterwards, but here is what I got..

LF 773
RF 843
LR 687
RR 683
TOTAL 2986

With Driver and fuel
LF 853
RF 883
LR 814
RR 684
TOTAL 3234

Did you change the back at at.. did you measure
the front(from the fender opening before and after)
you changed things

I agree with Steve, my Challenger is ladder as well and when scaled and set up correctly leaves even, shouldn't need a anti-roll bar Don. One other thing is verify all the lock nuts on your ladders are tight and not allowing any twisting movement within themselves.

I've tuned by adding preload/shock changes and using a scale. The final test may always need adjustment from the scale readings. If the weight is still in the range shown no wonder it goes right. The left rear is 130 lbs heavier than the right. It would benefit moving weight to the right. If that's not possible in my opinion it needs more than a 1/4 turn. I usually count the flats on the adjuster. My bet is it'll take 3-5. Start at 2 and work your way up. The ladder bar in itself works as an anti-roll bar unlike a 4 link. If there is very little flex it won't need one. All depends on how stiff the chassis, housing, and bars are. Mine is stock frame rail with no ARB with 3-4 flats of preload (every car is different). Dead level,1.25-1.27 foot brake. This picture tire is 13.5 psi
Doug

Don BTW what does that car weigh? I run 8# and told by a few self believed chassis guru's over the years I was hitting my tires to hard and should add air like 9# which wreaked havoc with my car going right or left, I rotate my tires side to side every 25 passes to save the sidewalls and typically get 300 passes out of a set.

Guys I KNOW a ladder bar acts like a anti roll
and IF things flex the bar helps it.. my car was
a ladder bar before I changed it.. my Rampage is
a ladder bar... and Doug is right.. those weights
are way off... the RR should show close to the
other side and then add a bit off preload.. if you
have a LOT of preload for the launch it does the
exact opposite on the shut down.. thats why you
dont want to add a lot... there are others on here
that have added a bar and it helped big time... and
I fought that idea.. but if you cant move weight..
then there is a problem
EDIT
JMO but I would see if I can move 150# to the RR
and with that 20# you might not need any preload
or you would be adding a small amount

Anyone who runs roundy round could see that the cross weight is light. If this is a coil over suspension, just increase pressure L/F and R/R . That will decrease pressures on opposite cross weights at the same time.

Just a reminder, when jacking weight around, especially on a ladder bar car, don't forget to remove one of the bar bolts at the housing, CANT JACK WEIGHT IF YOU DONT. Put something that is your weight in the seat (I used feed bags) then adjust weight. What the weights are before you're in the car means nothing. Driver side front should have more, back equal. When car launches that left front weight goes to right rear.

[/quote]
He needs to put the anti roll on first then see
about air.. its loading the RR harder due to twisting..
if it applies equal load to both tires it might be fine
[/quote]

So what size anti roll bar? Is it one size fits all for the diameter?

Would a anti roll bar be good to have ???Yes but it is not the end of the world. A ladder bar car could be set up to go straight without one. It really needs to be put on scales with driver weight in seat and set up with about 20-30 lbs heavier on right rear than lt. he is 130 lbs light on the rt rear that is why it is going rt. left tire is working harder and driving the car rt.

Agree with scale the car, and preload should fix it.
http://www.jerrybickel.com/complete-guide-to-chassis-performance-manual-rt-2000.html
buy Bickel's book best book on the subject. It covers a lot of four link, but ladder bars use same principles. Morgan's doorslammer book is good to, but Bickel's is written more with the racer in mind.

Thanks everyone for your advice and suggestions..


I really didnt want to spend the money.. specially with TAXES due next month and all the other projects we have going on.. but I ordered a set of scales today and will re-weigh the car..

Thanks again all

Hey BUDDY. Can I borrow them. LOL

I put an anti-roll in the Arrow and it was well worth the expense. It's a 4-link car and extremely narrow. To much pre-load and you can risk the car wanting to drive left or right down track.

Yes just put it on the scales and move weight..
dont just add pre load.. that will just make you
turn left on the shut down.. then see what you
have... hopefully it will be level

So what size anti roll bar? Is it one size fits all for the diameter?

NO! The effect of an ARB varies as the 4th power of the diameter: a 1" bar is over three times as stiff as a 3/4" bar.
This will also vary greatly by the length of the link (or arm) to the chassis: longer softens bar action.
If you're adapting an existing bar, one with splined ends makes pre-load bias easy.

If it has chassis flex, no amount of adjustment is going to keep it from rolling over.

As for the tires....MORE air is going to wrinkle the tire HARDER as it puts more rubber on the ground and INCREASES bite. Looks like it has more than enough bite now........too much