Moparts Tech Archive
Rear Suspension
Ladderbar ?'s
advice on ladderbar tuningbadasmopar
Moparts Member
Posts: 284
From: Portland
Registered: Dec 2001
posted 05-02-2002 02:19 AM
I need a little advice on tunning a set of ladder bars, Moving front point up or down, softer shock settings or harder etc etc what does what to the launch of the car? The car is 60' in the 1.8-1.7 sec range with wheel spin past the 60'. Best et after less then 10 passes is a 8.1 1/8th with a 88mph. I leave the line on the footbrake at 2500 rpm.
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carl
Moderator
Posts: 6973
From: Ohio
Registered: Nov 1999
posted 05-02-2002 02:25 AM
Well you're to far away for me to drop by!!! LOL
But it sounds like you need to just start over, lookin at those #'s above.
Set the driver side bar at 0-1 degree up on the lower bar, The pinion angle at 1-3 degrees nose down, and 1/2 a hole preload on the pass side bar.
I'd start there with those settings and put the car on 4 corner scales if you have access to them and fine tune the corner weights from there.
carl
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gregsdart
Moparts Member
Posts: 1315
From: Mn USA
Registered: Jan 2001
posted 05-02-2002 08:02 AM
Also what tires,shocks,trans, convertor, wieght of car, motor etc are you using? All this info will help us to give a better answer.
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badasmopar
Moparts Member
Posts: 284
From: Portland
Registered: Dec 2001
posted 05-02-2002 08:34 AM
69 dart, 3450lbs, 440, 28x12.5 M/T street slicks, Competition engineering shocks rear, and cheap monroe shocks front. Converter is a 3000 stall but flashes to 3800-4000. Out back in the 8 3/4 are 4.88 gears. Engine was in a different car before, without better heads and had a best 60' of 1.5 on leafsprings. what kind of tinkering around with the front mounting point make, pinion angle, what kind of shock settings will make the tire hit harder. Dont know much about ladder bar suspensions and how things will affect what. You know of any good books or websites that can explain some of this stuff?
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Leigh
Moparts Member
Posts: 1544
From: Censored, MN
Registered: Mar 2000
posted 05-02-2002 06:59 PM
Moving the bar up will give a quicker, harder hit. You may need a good double adjustable shock to help control the speed of the hit. I would say ol' Carl is pretty close, only thing is the pre load deal, I don't run any, some cars need some. If it goes straight, then leave it alone, and try a level (at race ride height and weight)ladder bar height, and a fairly soft bump, and a tight jounce. I'm guessing you will be close. Welcome to "what will my car need for ladder bar settings" club. You will find that what others run may not even be close for your car
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Bumps440
Moparts Member
Posts: 206
From: westbury,NY
Registered: Feb 2002
posted 05-02-2002 07:11 PM
Interesting conversation here . I was in this boat once , solved the spin problem by tightening both front and rear shocks. now need to work on poor 60 ft times. New convertor is next to try.
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badasmopar
Moparts Member
Posts: 284
From: Portland
Registered: Dec 2001
posted 05-03-2002 08:14 AM
Yeah the car leaves the line nice and straight, no fighting it to keep it straight. Had problems doing a good burnout last week and had the same 60' as with a good burnout, so I guess that its all in how the ladders are set up. Just got a few books today, Door Slammers the chassis book, and Bracket. I would recomend the Door Slammers book, it looks very detailed info. I can see that alot of it is going to be trial and error, thanks for having me in the club hehehe Anybody else have any info on what works for them?
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info provided by members listed above
Ladder bar questions
gd1996
Moparts Member
Posts: 2501
From: Latrobe, PA
Registered: Jan 2002
posted 11-14-2002 11:41 PM
I have ordered all the parts to backhalf my car, but didn't get the ladder bars yet. How long of ladders should I use? There are 32", 33", and 36" Its for a 70 rr, s&w's catalog says longer for bigger cars, is this really necessary? I know of people using 32" on b-bodies and say either are fine. Should I get a double adjustable ladder bar? Chromoly, teflon, or standard ends?
Also how long of a coil over should I get, there are ones that take a 12" spring, 14" etc... I want it to ride low, but will be a street driven car too. Thanks!
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GLENNP
Moparts Member
Posts: 108
From: GRANBURY TX. USA
Registered: Apr 2002
posted 11-15-2002 11:39 AM
Yes longer would be better (for a b-body) and you'll thank yourself at the track if you get the double adj. ones. As far as what ends....you need to decide what the car is going to be used for. A lot of street action you might want to go with the teflon or rubber ones. Limited street but lots of track time I would go with the solid rear with the spherical front. I have used solid and sph. with grease zert added, worked great.
I've had two ladderbar cars that I built myself and I helped on a 4-link 67 mustang. LB car much easier to build and adjust. Unless your gtxmonte who is racing ALL the time and needs every possible advantage he can get. Just remember how much fun actually making the pass down the track is and not tring to figure out why the car is not launching correctlly because of all the 4-link variables.
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gregsdart
Moparts Member
Posts: 1767
From: frostbite falls Mn USA
Registered: Jan 2001
posted 11-15-2002 03:48 PM
One of the alston chassis outfits offered a special washer/rubber boot type setup to protect the rodends and keep the dirt out. I don't know much about this, but thought i would toss it out there. It would seem that if a guy could protect the race type rod ends from road dirt, they might be a good bet for street strip? Any chassis experts care to coment on this idea?
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Fast Orange
Moparts Member
Posts: 706
From: Houston,Texas,USA
Registered: Apr 2000
posted 11-15-2002 07:50 PM
While we are on this thread, what does everyone think of the competition engineering
"ladder link" ladder bars? They appear to have even more adjustability than double adjustable ladder bars. Looks like you can adjust the pinion angle without moving the front of the bar to a different hole. Is this an advantage? http://www.competitionengineering.com/catalog/CategoryDisplay.asp?CatCode=11002
Scroll down to the bottom to see the "ladder link" bars
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69 S&M Cuda
Moparts Member
Posts: 697
From: westhills, california
Registered: Jan 2002
posted 11-15-2002 08:00 PM
gd1996,
I don't know if you have this link for Chris Alston, but here it is. www.cachassisworks.com
I used their ladderbar/coilover conversion on my Barracuda. I like the product and they where very helpful with any question that I had. If your considering using them
FastOrange,
I just checked out that web site that you posted. Pretty cool stuff. I like that safety link for the ladder bars. I did not know that was a NHRA requirement.
hummmmm.....note to self.... tell wife I would like that for my birthday
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badasmopar
Moparts Member
Posts: 516
From: Portland
Registered: Dec 2001
posted 11-16-2002 07:15 AM
I have the comp ladder link bars on my car and like them alot. IMO it makes sense to have the link the way it is on the bottom of the bar for adjustments. Regular ladder bars that dont have this binde when turning the adjustment buckle..........if you were to measure from the center to center of the two ends they increase in distance as you adjust outwards. With the ladder link there is no binde.
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reddodgehemee
Moparts Member
Posts: 508
From: bristol,indiana usa
Registered: Mar 2002
posted 11-16-2002 12:39 PM
Gd i agree also longer is better.I had double adjustable heims on my bottom bars,The rearend had no bind in them what so ever,which is hard to get out.I used the Koni single stage shocks w/14in springs
VIRGIL
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1expert
Moparts Member
Posts: 135
From: ravenna, michigan
Registered: Jan 2002
posted 11-16-2002 01:04 PM
have installed both on customers cars . if you are not making really high (1000+ ) hp i'd say ladder bar ! i did some ladder bar kits from chris alston and they were awesome right off the trailer and cost less than the 4 link . when you price the 4 link , remember they dont always come with the rod ends ! the ladder bar kit is easier and if you are not quicker than 9 seconds i think the 4 link is not needed , many cars are quicker than 9's and still have ladders etc. . and the ladder bars did not require cutting the floor ! the 4 link does ! good luck and remember save the whales (mopar wagons )! buy a mopar wagon and save em from the derbys ! ted
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markz528
Moparts Member
Posts: 257
From: milford, oh
Registered: Dec 2001
posted 11-16-2002 01:21 PM
I used the Alston Chassisworks ladder bars in my 67 Coronet. Right or wrong, I went with the 36 inch because of the long wheel base.
Car hooked fine with the 440. It will be interesting to see how well I will be able to tune the suspension with the new 528 motor.
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s&s
Moparts Member
Posts: 146
From: Memphis TN
Registered: Nov 2001
posted 11-16-2002 03:48 PM
Since you have all comp engineering parts already I would say stick with them. I run their ladder link bars on mine with no problems car runs 8.50's 1/4 mile. Also as badasmopar said no matter how far you turn the adjuster it will not get into a bind.
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ladder bar suspension
Author Topic: ladder bar suspension
JANDJ
posted 06-13-2001 11:01 PM
I AM CONSIDERING CHANGING OVER TO A LADDER BAR SUSPENSION AS I AM SICK OF THE SUPER STOCK SPRING SET UP LETING ME DOWN, WHAT LENGH LADDER BAR SHOULD I USE ON MY 70 RD RNR? ANY OTHER SUGGESTIONS WOULD BWE APPRECAITED.
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Chryco Psycho
posted 06-14-2001 12:24 AM
Go with the ladders you won`t regret it, the longer bars work better with the longer wheelbase the 36" will work great, you can either keep the leafs, to hold the body up,& use a floater or you can install a crossmember & use coilovers with a panhard bar , the second choice is lighter but will lighten your wallet more!
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gregsdart
posted 06-14-2001 12:44 AM
I have ladder bars on my dart, they are 30 inch and i wish they were longer. I would go as long as you can put under the car. Also if you don,t have the book door slammers, the chassis book, i would suggest you get it and read it through to get a better understanding of what will work best for you as far as mounts for the front of the bars, shocks etc. If you can put it in your budget i highly recomend a good double adjustable shock with coil over springs, the ability to adjust the shock in both directions is VERY important. I have AFCOs and i like them. Also plan a well braced front mount for long life.
Greg
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crankshaftkid
posted 06-14-2001 12:53 AM
Yes, get the book! I've had it for years and the newer one is updated...is the car mostly track? You may not like ladder bars on the street as they are somewhat noisy but if you are serious about being fast and consistant, go with em. I like the coilovers better too...Door Slammers: The Chassis Book, is by Dave Morgan.
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JERICOGTX
posted 06-14-2001 10:14 AM
JANDJ, 36" bars from S&W, remember to brace the 8 3/4! 15 passes and mine was bent at least 1 inch.
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Richard
posted 06-14-2001 10:42 AM
From a chassis builders perspective, longer ladder bars are not always better. The industry standard these days is 30 or 32".
Remember the days when ladder bars use to literally run clear up to the front wheels? They dont work. A lot will depend on how much tire you have, but in reality, the shorter the bar, the more leverage ratio you are using to plant the tires. Your rear suspension doesnt squat on the launch, it actually tries to seperate. The IC or instant center on a ladder bar is the front attaching point.
The further you move this back and up, the harder you are trying to force the rear axle down and out from under the car. It is kind of hard to explain, but if you can envision a pendulum turned horizontally. The further up you raise the front point, on launch, the rear axle will actually be forced down and the action of the pendulum will in essence try to drive it forward out from under the car. The shorter the bar, the more leverage you have on the rear axle housing.
Ok, long enough description. Personally, I would use a 32" bar with a decent set of coil overs. You will have a good suspenion that will be very tuneable and last you for many years to come.
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Anyone install ladder bar system with out tubbing?
DARTMAN928
Moparts Member
Posts: 1100
From: IN
Registered: Jun 2001
posted 01-20-2003 08:30 AM
Hey guys looking into some options right now.
I don't want to tub my car but a couple of questions what might work for me......
Cal-tracts, I will have to move my spring perches in and notch the frame.
Ladder bar, weld in a couple bars that I could remove later, like for the c-member and shock mounts
Four-link, not sure if this can be done without tubbing the car.
At this time I might up grade to a Dana, but I would like to know can my Dart hook better with a ladder bar set up with lets say a 29.5 13.5 tire or will the cal-tracts do the job. I was looking at the prices and a complete cal-tract set-up is about the same price as a ladder bar set-up.
Thanks
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Richard
Moparts Member
Posts: 3153
From: glendale, AZ
Registered: Nov 1999
posted 01-20-2003 08:38 AM
I put in ladder bars all the time on stock chassis cars. Is a far better suspension than leaf springs for drag racing.
4 link pretty much requires a back half for packaging.
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carl
Moparts
Posts: 9504
From: Ohio
Registered: Nov 1999
posted 01-20-2003 08:41 AM
Yes I did mine that way when I first took it off the street and started trailering it to the races.
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kingjr
Moparts Member
Posts: 2551
From: CT
Registered: Aug 2001
My Duster's new 3link is installed w/no tubs. I would highly recommend the Dana!
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DARTMAN928
Moparts Member
Posts: 1100
From: IN
Registered: Jun 2001
posted 01-20-2003 08:52 AM
kingjr,
Where did you get the three link? Is it just like a ladder bar system? Do you have any pics of the system from the side. What size tire and what kind of 60 ft. are you getting.
Thanks,
Rob
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kingjr
Moparts Member
Posts: 2551
From: CT
Registered: Aug 2001
posted 01-20-2003 09:00 AM
Yes it is ladderbar/coilover, just easier to type 3link and its synonymous. No side pics, 1.44 60' w/11.5x28" rubber.
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DARTMAN928
Moparts Member
Posts: 1100
From: IN
Registered: Jun 2001
posted 01-20-2003 09:03 AM
kingjr,
who's 3-link system is that and what kind of shocks are those?
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MoparTony
Moparts Member
Posts: 2121
From: Detroit area
Registered: Jul 2000
posted 01-20-2003 09:06 AM
Rob,
In the link I sent you you can see I have a leaf spring ladder bar set up. the only extra bar was for the ladderbars. I have the springs moved in and still use the stock shock mounts. The car is mini tubbed.
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J BODY
Moparts Member
Posts: 1219
From: Ft. Mohave, Arizona
Registered: May 2001
This is Richards handywork on my car with stock frame. I did cut my inner fender wells out and bring them in even with the frame. A two inch "mini tub" by adding onto the existing wheel well.
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