|
Re: ladderbar/anti roll bar ?
[Re: gregsdart]
#1239902
05/28/12 10:41 AM
05/28/12 10:41 AM
|
Joined: Mar 2006
Posts: 9,982
MI, usa
dvw
master
|
master
Joined: Mar 2006
Posts: 9,982
MI, usa
|
Quote:
Quote:
i'm guessing a guy could use a smaller diameter bar if using a kit with a 4130 tube vs. a home fabbed bar of .134 ms. tube ? what about pivots - bushings or bearings ?
I am sure you could go lighter/smaller with moly. Check the web sights of some of the chassis builders, there might be some answers there. The main thing is to keep in mind the total length of the tube, and how much twist it needs to resist. In my case, the worst scenario was with the ladderbar front mount at the neutral line. check out the pic of before the anti roll.
I certainly agree that Greg's bar corrected his twist. What I question is what was twisting in the first place. Thats a LOT of movement. Did the car steer right due to the right rear being pulled up into the body? How much did you have to change the preload before and after?
Doug
|
|
|
Re: ladderbar/anti roll bar ?
[Re: dvw]
#1239903
05/28/12 02:24 PM
05/28/12 02:24 PM
|
Joined: Jan 2003
Posts: 10,088
Frostbitefalls MN (Rocky&Bullw...
gregsdart
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 10,088
Frostbitefalls MN (Rocky&Bullw...
|
Doug, i believe the cause was the ladder bar front was in the bottom hole, which aggravates the situation. At the neutral line on the hit the left side leverage increases more than the right, and it gets out of hand in a hurry.
I could get the car to leave level, but the cost of that was inconsistency due to all the preload. By using an anti roll, most of the force that needs control is stopped dead by the anti roll, putting the weight on both back tires more evenly. The only force left to affect roll rotation is the reaction to engine torque, just like you see in a solid mount fueler leaving the line. The preload needed at that point is zero or greatly reduced.
8.582, 160.18 mph best, 2905 lbs 549, indy 572-13, alky
|
|
|
Re: ladderbar/anti roll bar ?
[Re: gregsdart]
#1239904
05/30/12 06:48 PM
05/30/12 06:48 PM
|
Joined: Mar 2006
Posts: 9,982
MI, usa
dvw
master
|
master
Joined: Mar 2006
Posts: 9,982
MI, usa
|
Quote:
Doug, i believe the cause was the ladder bar front was in the bottom hole, which aggravates the situation. At the neutral line on the hit the left side leverage increases more than the right, and it gets out of hand in a hurry.
I could get the car to leave level, but the cost of that was inconsistency due to all the preload. By using an anti roll, most of the force that needs control is stopped dead by the anti roll, putting the weight on both back tires more evenly. The only force left to affect roll rotation is the reaction to engine torque, just like you see in a solid mount fueler leaving the line. The preload needed at that point is zero or greatly reduced.
My take on this. The car previously needed a lot of preload. Now the anti-roll bar is only in play when the body or suspension is twisted by torque. As the torque output is reduced after the hit the need for the bar to control body roll is reduced. At that point the excessive preload in the previous setting could have been detrimental by over loading the right rear tire.
Doug.
|
|
|
Re: ladderbar/anti roll bar ?
[Re: dvw]
#1239905
05/30/12 08:43 PM
05/30/12 08:43 PM
|
Joined: May 2011
Posts: 625
Oakville, Wa
HOTMOPR
mopar
|
mopar
Joined: May 2011
Posts: 625
Oakville, Wa
|
Anti roll bars work great on ladder cars. Trust me! It no longer does this! No other adjustments just added the bar.. I am try to find what bar I used but it wasnt one with splined ends. I know I couple NOS cars that have stripped the spines out of the arms.. 
Last edited by HOTMOPR; 05/30/12 08:44 PM.
|
|
|
Re: ladderbar/anti roll bar ?
[Re: HOTMOPR]
#1239906
05/31/12 12:03 AM
05/31/12 12:03 AM
|
Joined: Jun 2008
Posts: 186
Middleton, ID
curleysracecars
member
|
member
Joined: Jun 2008
Posts: 186
Middleton, ID
|
An ARB will usually help a ladder bar car. Put it in there if you are doing other fab work. The statement about using a torsional spring for the actual ARB is wrong...all commercially available ARB's use a piece of tubing...either mild steel or chromoly. Its really that simple. Typically, the arms are 6-8" long. Put it in while you're in there and be done with it.
Kyle Curley
|
|
|
Re: ladderbar/anti roll bar ?
[Re: curleysracecars]
#1239907
05/31/12 12:14 AM
05/31/12 12:14 AM
|
Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
|
Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
|
Quote:
An ARB will usually help a ladder bar car. Put it in there if you are doing other fab work. The statement about using a torsional spring for the actual ARB is wrong...all commercially available ARB's use a piece of tubing...either mild steel or chromoly. Its really that simple. Typically, the arms are 6-8" long. Put it in while you're in there and be done with it.
Your wrong... my S&W anti roll bar is a solid bar
4130 steel torsion shaft with splined ends
|
|
|
Re: ladderbar/anti roll bar ?
[Re: Evil Spirit]
#1239908
05/31/12 11:18 AM
05/31/12 11:18 AM
|
Joined: Jan 2003
Posts: 10,088
Frostbitefalls MN (Rocky&Bullw...
gregsdart
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 10,088
Frostbitefalls MN (Rocky&Bullw...
|
Quote:
I just kinda agree with Raff's statement - " on a ladder bar set up it most likely wouldnt need to be as strong because its just covering up
flex in the ladder bar system". I've always tried to fix the root of the problem - if the car doesn't leave straight - adjust the ladder bars. If the ladder bars are flexing - fix the ladder bars. We just haven't found a need yet for a torsion bar setup on a ladder bar car. Installed about a half dozen on Mustangs with "stock" style suspensions, but no ladder bar cars. 
The twisting force that causes roll rotation doesn't give a darn what type suspension is under the car. It only sees what the Instant center length and height is. Obviously the different types of suspension help or aggravate the problem.
So all the anti roll does is put a stop to the forces at work which twist the car. If you can band aid the situation with preload, fine. That works so well in a lot of cases that an anti roll will show very little improvement simply because there is enough traction to do the job. As power goes up and/or traction goes down, the car needs every last bit of help it can get. That is where the anti roll works well. It allows a chassis tuner to go to combos of I C that will really aggravate roll rotation with out having to add preload, which is going to affect the chassis the whole length of the track.
I did find ways to keep the car level with the ladderbars, but the anti roll improved the 60 foot CONSISTANCY as well as a good gain in 60 ft ET.
One question- after seeing two photos of ladderbar cars twisting violently how can anyone think it is any less of a problem than other suspension types?
8.582, 160.18 mph best, 2905 lbs 549, indy 572-13, alky
|
|
|
Re: ladderbar/anti roll bar ?
[Re: moparx]
#1239910
06/03/12 10:02 AM
06/03/12 10:02 AM
|
Joined: Jan 2003
Posts: 10,088
Frostbitefalls MN (Rocky&Bullw...
gregsdart
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 10,088
Frostbitefalls MN (Rocky&Bullw...
|
Just like gun drilled axles, the strongest lightest piece will be a tube of the biggest diameter you want to work with. Not knowing the torsional strength of various tubes or what I was trying to deal with led to the trial and error method. I know an 8.80 3000 lb 30 inch ladderbar car with a 11.17 SLR will eat a 1.25 diameter by .125 wall tube, and it won't hurt a 1 3/4 x .134 tube. Your requirements will probably be different, but looking down the road five or ten years as to what you will be doing to make the car faster is good to consider. The length of the arms on the tube will also make a difference. The shorter you can make them within reason, the better. Less leverage on the tube.
8.582, 160.18 mph best, 2905 lbs 549, indy 572-13, alky
|
|
|
Re: ladderbar/anti roll bar ?
[Re: gregsdart]
#1239911
06/03/12 03:30 PM
06/03/12 03:30 PM
|
Joined: Aug 2005
Posts: 774
Southington Ct.
turbobitt
super stock
|
super stock
Joined: Aug 2005
Posts: 774
Southington Ct.
|
Guys, Don't mean to polute this thread with non-mopar but I just ran by Buick on Friday with Ladder bar and no sway bar. Car is heavy at about 3600# race weight. Made my first 8 second pass. I think the car handled well. Didn't seem to twist much so not sure how a sway bar would help or hurt. I will say this though, I have mine mounted to a box tubbing x-member. About 3 weeks ago, I noticed that the mounts started to rip the metal. The welds were OK but the mounts were just failing the x-member from fatigue. I do a lot of street driving and had this on the road for the last 12 years. If you can, have plates welded to the box tubingf to give it further strength. Then have gussets made to give it further strength. http://www.youtube.com/watch?v=Sp3GqdqwQdA&feature=channel&list=ULAllan G.
1970 Challenger w/572 Hemi street car and my pride and joy.
1986 T-Type with 272 Stage 2 Buick V6 engine - True 8 second street car. Just updated the engine and put down 928 HP @ 35# boost to the ground on chasis dyno.
1976 Cee Bee Avenger Jet Boat - 460 Ford powered.
|
|
|
|
|
i will now plan for a bar while the car is still in the build stage. i can easily make attaching points on the bench rather than lay under after the car is done. the next question that comes to mind is this. how does one come up with a bar size ? is it based strictly on material used, such as a solid splined bar or tube, or does rear weight bias have the defining bar/tube diameter requirement ?