Re: ladder bar setup
[Re: birdtracker]
#3141904
05/02/23 03:01 AM
05/02/23 03:01 AM
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Joined: Aug 2003
Posts: 43,232 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,232
Bend,OR USA
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3,000 pound car 14X32 slicks, trans brake. 28 inch bars. Bar flat or angled? Birdtracker Test, test and test some more so you learn what works best on YOUR CAR Both Dusters I had (one leaf spring and one coil over) like, best 60ft. and reaction times, the front eye in the lowest hole in the front brackets
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: ladder bar setup
[Re: Cab_Burge]
#3141908
05/02/23 06:41 AM
05/02/23 06:41 AM
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Joined: Jan 2003
Posts: 2,345 west palm beach, florida
modelmakerinc
top fuel
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top fuel
Joined: Jan 2003
Posts: 2,345
west palm beach, florida
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78 D-150 I installed the bars at 2.5* nose down in their lowest position, with the expectation to be installed for initial use one hole up. this will give us a little adjustment to increase or soften (lower or raise respectively) the "Hit'
The trucks chassis posed some issues due to how low the front crossmember was going to be installed, a cars chassis is considerably different and you should be able to set it up to use (adjust-ability for tuning) 4 or all 5 front holes
Last edited by modelmakerinc; 05/02/23 10:19 AM.
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Re: ladder bar setup
[Re: DoubleD]
#3141922
05/02/23 08:48 AM
05/02/23 08:48 AM
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Joined: Mar 2003
Posts: 2,515 PA
moparacer
master
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master
Joined: Mar 2003
Posts: 2,515
PA
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Slicks, I say it's going to work best with a few degrees down angle.
If you put a drag radial on it then you might level it out.
67 Barracuda street/bracket car 11.27-119 68 Dart 502 BB 8.70s-152 414 cid SB Dragster 7.65-174
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Re: ladder bar setup
[Re: birdtracker]
#3141925
05/02/23 09:03 AM
05/02/23 09:03 AM
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Joined: Nov 2015
Posts: 880 Missouri
jwb123
super stock
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super stock
Joined: Nov 2015
Posts: 880
Missouri
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The only bad thing about a ladder bar setup is if it is right, it works great, if it is installed wrong not much you can do about it, except cut brackets off and start again. Plus if you keep the car and keep improving it, what happens when you overpower the suspension and lack of adjustment keeps you from tuning it? For just a little more time and money a 4-link will give you adjustment and maybe even make the car worth more when it is time to sell. I like to use a suspension program like Performance Trends 4-link calculator, it also does ladder bar setups. plug in the numbers and see where those brackets need to be welded. https://www.performancetrends.com/4link.htm
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Re: ladder bar setup
[Re: jwb123]
#3141936
05/02/23 09:38 AM
05/02/23 09:38 AM
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Joined: Mar 2003
Posts: 2,515 PA
moparacer
master
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master
Joined: Mar 2003
Posts: 2,515
PA
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The only bad thing about a ladder bar setup is if it is right, it works great, if it is installed wrong not much you can do about it, except cut brackets off and start again. Plus if you keep the car and keep improving it, what happens when you overpower the suspension and lack of adjustment keeps you from tuning it? For just a little more time and money a 4-link will give you adjustment and maybe even make the car worth more when it is time to sell. I like to use a suspension program like Performance Trends 4-link calculator, it also does ladder bar setups. plug in the numbers and see where those brackets need to be welded. https://www.performancetrends.com/4link.htm Years ago I had a Dakota pickup that had the chassis brackets installed too high for ladder bars. The bottom hole they still had a slight upward angle. It was too violent and we ended up cutting them off and lowering them to get the bars angles down. Truck was fine after that. I say put the brackets were the bars are level in the middle hole and you have holes to go up and down for either adjustment.
67 Barracuda street/bracket car 11.27-119 68 Dart 502 BB 8.70s-152 414 cid SB Dragster 7.65-174
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Re: ladder bar setup
[Re: dvw]
#3141993
05/02/23 12:53 PM
05/02/23 12:53 PM
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Joined: Mar 2003
Posts: 2,515 PA
moparacer
master
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master
Joined: Mar 2003
Posts: 2,515
PA
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The attachment point is the IC DVW as you know and higher is always a higher AS value. Ladder bars are always so short that you always have some ridiculous amount of AS value and are trying to take some of that initial hit out of it and control it with slicks. That is why with slicks its usually better to have the bars running downhill slightly IMO but I realize all cars are different. Shocks control it all too and years ago we never had valving to control the hit properly so we always ran them downhill. Radials and no prep are a different animal.
67 Barracuda street/bracket car 11.27-119 68 Dart 502 BB 8.70s-152 414 cid SB Dragster 7.65-174
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Re: ladder bar setup
[Re: birdtracker]
#3142351
05/03/23 05:52 PM
05/03/23 05:52 PM
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Joined: Nov 2015
Posts: 880 Missouri
jwb123
super stock
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super stock
Joined: Nov 2015
Posts: 880
Missouri
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so I have the car up on stands right now and the rearend out of it. The axles and pig are out of it. The car will not 60 foot the way it was.The bars were down 9 degrees. I talked to another racer that is old school and he recommended the string from the tire to camshaft and see where that intersects. Work in progress. Birdtracker The height of the camshaft is what is usually used when you don't take the time to calculate the center of gravity vertically for the car. It is a good estimate and I have used it a lot. Real way is to use scales and then jack up the front and use a formula with the weight change to get the real center of gravity height. Most of my experience is with 4-links, and I chased my tail one time, over 60 foot times and when all was said and done the rear spring rates were too stiff. Instant center changes would not solve the issue.
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Re: ladder bar setup
[Re: jwb123]
#3142381
05/03/23 08:50 PM
05/03/23 08:50 PM
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Joined: Mar 2006
Posts: 9,860 MI, usa
dvw
master
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master
Joined: Mar 2006
Posts: 9,860
MI, usa
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What is the current set up? Weight, F/R weight distribution, shocks, springs, ladder bar length, ladder bar front heim bolt C/L height from the ground, ladder bar length, converter, rear gear ratio trans 1st gear ratio, power level. Doug
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Re: ladder bar setup
[Re: birdtracker]
#3142386
05/03/23 09:11 PM
05/03/23 09:11 PM
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Joined: Jun 2004
Posts: 926
birdtracker
OP
super stock
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OP
super stock
Joined: Jun 2004
Posts: 926
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Re: ladder bar setup
[Re: birdtracker]
#3142395
05/03/23 10:06 PM
05/03/23 10:06 PM
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Joined: Jan 2003
Posts: 4,244 Canada
Kam*Kuda
master
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master
Joined: Jan 2003
Posts: 4,244
Canada
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I learned a lot from watching and rewatching SBCWilson https://www.youtube.com/watch?v=HF9cvi4I_OUI am a radial tire car and look for as much separation as I can get (aka AntiSquat)
1970 Barracuda Convertible 1968 Satellite Street Strip car 1654.5 Mustang 1955 Land Rover
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Re: ladder bar setup
[Re: birdtracker]
#3142435
05/04/23 08:13 AM
05/04/23 08:13 AM
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Joined: Mar 2006
Posts: 9,860 MI, usa
dvw
master
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master
Joined: Mar 2006
Posts: 9,860
MI, usa
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Hit the little gear icon 5th from the right lower corner of the video screen. Then go to playback speed. Set it to .25 speed. Now you can watch it slow. For this video. If you click your mouse on the red line right above the sound icon you can watch the hit over and over everytime without watching the entire video. I see a few things. First the rear axle housing separates from the body and slams the tire violently. This is a result of the rear shock rebound (extension) setting being too loose. Then the tire bounces the housing back towards the body causing spin. The rear shock compresion is also to loose. With a 28" ladder bar the rear shock settings are going to have to be pretty tight to control the housing movement. Next is the front. The rebound is to loose there as well. The tire comes off the ground nearly immediately. then any help from the front suspension is lost. This makes the spin even worse. Ideally the front tire should stay on the ground 1/2- one full revolution of the rear tire. Your shocks are so out of whack I'd start there before changing anything else. Watch this video at the same .25 playback speed. It's already slow mtion but .25 makes it even slower. watch the rear housing to the body. And in reality the front shock rebound is too loose. https://youtu.be/D3G3mR1WxjIDoug
Last edited by dvw; 05/04/23 08:26 AM.
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Re: ladder bar setup
[Re: birdtracker]
#3143353
05/09/23 10:21 AM
05/09/23 10:21 AM
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Joined: Feb 2003
Posts: 4,953 Houston, Texas
TheOtherDodge
master
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master
Joined: Feb 2003
Posts: 4,953
Houston, Texas
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car only went 9.50 at 140 mph. It will go 8.90 or 8.80 when I get the rear sorted out. I actually have the rearend out of it right now. It was tearing the lower shock mount off the rearend.I am supposed to stop by my welder guy to see what he says. I bought a Fab rearend but there is a couple issues with width of the center section is wider than my old housing mounts by an inch. If he can fix it I will go that route. If not a road trip of 4 hours will be in my future. Birdtracker If you only went a 1.45 short time but a 9.50, then you are leaving a lot on the line, literally! You should be in the 1.2x. My truck will go 1.37-1.39 on a 9.7 and is 350 lbs heavier so you have some work to do on the short times!
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