Ladder bar tuning / adjusting
 

From your experiences , did moving the bars up or down , make the car more wheelstand prone?

Re: Ladder bar tuning / adjusting
 

Moving the front of the ladder bar up will raise the instant center and will be prone to wheelstands.

Re: Ladder bar tuning / adjusting
 

For some reason I always though it was the other way around..........damn it ,I'm still dumb:D

Re: Ladder bar tuning / adjusting
 

Also..........I don't think I can get the pinion angle I want after I move the bars up..........extending the adjuster on the bottom bar is probably going to not allow me to get the bolts back in the housing bracket on the rear end.
In case someone would ask , the usual 2-3 degrees down is what I'm after......
In fact a well known chassis shop suggested just increasing the pinion angle would make the car more wheel stand prone?
Not sure why that would change anything.
Between bars up , pinion angle down , shock tuning...........damn.
The car leaves flat now...........I'm looking for more drama...LOL

Re: Ladder bar tuning / adjusting
 

My thought is the ladder bar rotates up due to axle torque and is pushed forward by the driving force of the tires. Moving the pivot up wouldn't affect the upward force on the chassis, but moving the pivot point down would be pushing further away from the center of gravity. I would think that would cause the nose of the car to go higher.

If you disagree, please explain your logic.

Re: Ladder bar tuning / adjusting
 

Uh , yeah.......thats exactly what I thought also.
Some guys use the "refrigerator or box" logic..........so what you suggest coinsides with THAT explanation , anyway.....hell if I know........I guess trying and testing is the only validation.:confused:

Re: Ladder bar tuning / adjusting
 

I haven't owned a ladder bar car in a number of years, but I think I remember that the overall length of the bar has a significant effect on "hit" versus "wheelstand". Short bars smack the tire very hard, whereas longer bars tend to make the car wheelstand more. The principle still makes sense to me, because a longer bar essentially moves the intersect point forward, which would apply more rotational leverage to the chassis. I think...:D

Re: Ladder bar tuning / adjusting
 

Move the bar up for a harder hit. I have run my car that way for 20 years. Adjust your front shocks to control wheel stands. If the car isn't pulling the wheel up loosen the front shocks.

Re: Ladder bar tuning / adjusting
 

:)

Re: Ladder bar tuning / adjusting
 

Joespanova: You may want to modify the lower rear section of your ladder bar to make it adjustable. Lower adjuster link. This will give you the added length you require.

Re: Ladder bar tuning / adjusting
 

Why don't you guys that don't understand how suspension works in a racecar with suspension read a book???????

"Door Slammers, The Chassis Book" by Dave Morgan would be an excellent place to start........

Stop guessing what works and listening to other people that know even less than you do and just buy and read a book that was written by an expert and has been useful for years.............

OR

Pay "an expert" to set up your chassis......

Either solution will be cheaper that guessing....

Re: Ladder bar tuning / adjusting
 

WHO'S he talkin' to?:D
Yeah , a friend of mine has that book.......I'll borrow it.

Re: Ladder bar tuning / adjusting
 

The original post asked for a result from experiences. I'm sure he knows how to read a book.

Re: Ladder bar tuning / adjusting
 

Yes ....... in fact I'm so good I can even read with one eye closed.........
BTW , someone suggested "modifying" my bars or getting and adjuster.
My bars are real good n' beefy Chassis Works bars that DO have said adjuster...............also use a 1'' eye bolts in front.....very beefy ,indeed.
What I was saying was..............if I move the bars UP 1 hole , I don't think I'll be able to adjust the bottom adjuster enough to get the pinion down..........without losing alignment of the upper housing bracket hole.........I'm going to try.

Re: Ladder bar tuning / adjusting
 

I am by no means an expert but I have been running a leaf spring/ladder bar car for about 25 years. There really is no correct answer to your question. Way to many variables. The Dave Morgan chassis book is very good and I have one as well.

The tried and true for most cars as a starting point is to have the bottom bar parallel to the bottom of the car not the ground. You can put an angle finder under your drivers door and then match that angle to the bottom bar.

Pinion angle is another hot debate topic on ladder bar cars. You will see people say 1-5 degrees down.

My car is a 10.90 bracket car with a Jerico. Move your bar and see what happens. Nothing to loose.

Re: Ladder bar tuning / adjusting
 

You should leave the top housing bolt alone, move the front up one hole and then adjust the bottom rear "adjusting link" to reset the pinion angle.

Re: Ladder bar tuning / adjusting
 

Check out the link below (page 6);

http://chassisengineering.com/documents/3606.pdf

Re: Ladder bar tuning / adjusting
 

I always made any adjustment on my ladder bar car with weights in the drivers seat that was equal to my own weight. That way the bars were adjusted as the car would normally sit ready to race. I would set any pre-load the same way.

Re: Ladder bar tuning / adjusting
 

I probably said that wrong......what I was saying is the hole geometry will "conflict" with the bars once I start moving the adjuster as much as I need to get the angle down.......in other words you really only have a limited amount of range to move /adjust.

Re: Ladder bar tuning / adjusting
 

I looked through that.........
"raising the front of the bar DECREASES the "hit' ? Really , I thought it was the other way around....
Raising the front of the bar INCREASES hit , lowering puts more "squat" in the car and LESS hit.........or so some think.

Re: Ladder bar tuning / adjusting
 

I understand where you're coming from.

First of all, I used their bars for a long time, they are beefy for sure! And they told me they would never use a heim joint in the front, and I see why. It takes a ton of runs, but they eventually start to bend.....

When the bars and brackets are first setup you need to make some compromises. You just ran into one of those initial issues. To move your bar you may run out of adjustment range with the adjuster on the lower bar. if that is the case, you have to remove the bars completely and change the position of the upper and lower rod ends so everything will line-up once again. Pain in the butt for sure!

When I did mine I put the ladder bar in so the front was running downhill compared to the rocker panel. I have been anywhere from 1.50 to 1.2x 60fts, depending on what I was doing with the engine at the time. Has always been a Power Glide with 1.80 low gear, but rear gears ranged from 4.30's to 4.88's, and no nitrous or a lot of nitrous. It always hooked, wheelstands where an issue with a lot of spray. Used wheelie bars to control that. I never, ever mover the front of the ladder bar though.

Maybe if I wanted to hit the tree better I could experiment, but unlike a 4 link, it isn't so simple to just move the bar up or down a hole........

Re: Ladder bar tuning / adjusting
 

[QUOTE=cmracing;532611]I understand where you're coming from.

First of all, I used their bars for a long time, they are beefy for sure! And they told me they would never use a heim joint in the front, and I see why. It takes a ton of runs, but they eventually start to bend.....

I have been running Art Morrison ladder bars on my 3100 lb bracket car for 30 years now, along with the basic Morrison coil spring kit. When I bought the ladder bars, we installed them per Morrisons instructions, with the lower bar level, and parallel to the rocker panel. When I bought the ladder bar kit, the bars came with 6 3/4" solid rod ends, and no lower adjusters. After a while, I elected to replace the front solid rod ends with good quality Aurora chrome moly Heim ends, I just did not like the idea of not being able to tighten the front ladder bar bolts, which would cause binding. With the spherical rod end, you can tighten the bolt up, and still have the ball free to pivot. I have never found any bending or play in the front rod ends, although I have replaced them a couple of times for peace of mind. There is a big difference between a good quality $75.00 a piece joint, and a no name $12. piece. I also had lower bar adjusters installed about 20 years ago, so I could try moving the front ladder bar pivot location. Going lower made the back of the car rise more, going to the top of 3 holes didn`t really make a noticeable change, so I went back to the middle position, and have not touched it in many years. The car has always hooked well, and went straight, so I am leaving well enough alone. 3100 pound back half car with 105 1/2" wheelbase, 56% on the front tires, 32" long ladder bars, with a mild 428 FE Ford and 4 speed Jerico, best 60 foot of 1.29, 9.97ET@132 MPH.

Re: Ladder bar tuning / adjusting
 

some more information to consider;

*this Monte Carlo is 3155 pounds with driver
*408 CI SBC
*powerglide
*footbrake
*31 x 13 radial tire

*The ladder bar is 32" center of rear axle to center of the front rod end. It is 2 degrees down in relation to the ground in this photo.The right ladder bar has one-half flat pre-load

It also has an anti-roll bar that is set neutral.

This car is excellent, consistent, and predictable. It runs 6.0's 1/8 mile

Re: Ladder bar tuning / adjusting
 

I have been racing a ladder bar car for over 35 years. This is how I set my car up
The bottom bar of the ladder bar is set to2 degrees down angle from the rocker panel. Then 2 degrees pinion angle. Do not go beyond parallel to the rocker or frame or the car will not plant the tire. You can make small adjustments to the angle by adjusting the ride height. Bad track loosen the shocks front and rear. Good track tighten the shocks. If you have double adjustable front shocks set the compression near as tight as you can on the front to keep the from slamming down hard and unloading the back tires or bouncing
My car will 60 ft in the high 1.20s and 330 in the 3.96 range when conditions are good and the engine is making power. I have a powerglife trans in my car. 3160 lbs.

Re: Ladder bar tuning / adjusting
 

I've had the bars off completely , and IIRC thats when I made the observation about everything not going back together without a fight........been a while though. Actually , moving the bars up or down IS relatively easy.......suprised you would suggest that.

Re: Ladder bar tuning / adjusting
 

How quick do you run when you get the 1.2? 60fts? You do run a 350 right?

Re: Ladder bar tuning / adjusting
 

9.90. Yes actually about 365 cu in as the engine is about .075 over

Re: Ladder bar tuning / adjusting
 

Geezus...........
see this is what this is really all about.......better 60s ,launch etc etc.........
I'm consistent in the 9.40s and I've NEVER had a 1.20 ANYTHING 1.30s YES..........1.32-1.34ish......

Re: Ladder bar tuning / adjusting
 

Moving the front of the bar is a piece of cake, but getting the pinion angle back to where you want it can be a whole 'nother story. You can easily run out of adjustment on the double adjuster, now what. You are forced to take the bars off to change the length of the upper and lower rod ends and get the double adjuster back in a usable range.

Re: Ladder bar tuning / adjusting
 

I have a 66 Chevy II with a old school leaf spring ladder bar set up from the early 80's (I'm not joking). We have a 327350hp combo. We have the bars in the bottom hole with front shocks turned as tight as they will go and travel limiter a tight as they can go also. We are trying to stop the car from turning over. Anybody at the track can verify what I'm.saying. This thing goes higher in second gear than the actual launch. We run a stick car so different from setups talked about on here. Last time out in SS/H we ran career best of 9.65@135 with a 1.43 60'

Re: Ladder bar tuning / adjusting
 

Ed , my car IS a stick car also........2.98 low , 5.67 Rr. Grs....... McLeod plate , aluminum wheel.
You cant be happy with 1.40s 60s:D

Oh yeah , almost forgot.I have Chassis Works "floaters' on mine too.............with mono leafs. The car was built in early 90s.

Re: Ladder bar tuning / adjusting
 

I have a 3.19 with a 6.17 at 3025lbs. 2.98 isn't enough IMO

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Those are very impressive numbers that you're running Ed. Off topic but if you don't mind me asking, what rear are you running and what kind of gear life?

Re: Ladder bar tuning / adjusting
 

Dana 60 current ring and pinion has about 70 runs on it.

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Those are rear wheel 60 ft times. You wont run as fast as Ed is with a true 1.40 60 ft. Great to see Ed's car running that well.

Re: Ladder bar tuning / adjusting
 

Check and see if Santhuff makes shocks for your car. They will control the wheelstands. They aren't cheap but are the best. Good to see your car running that strong. That is getting it done!

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I have a 1.96 low in the glide and a 5.86 in the rear with a 100 inch roll out radial tire. The glide is handicapping me a bit in comparison to the 3 speed cars I suspect I could pick up about .015 with a good 3 speed trans. I have the power but cant run the short times of some of the really fast cars in my class. I have run next to those guys and their short times blew my mind.

Re: Ladder bar tuning / adjusting
 

I always thought the Santhuff's fronts big difference was their compression valving, controlling the car after it comes down from a large wheel stand. Are their rebound qualities equally unique?

Re: Ladder bar tuning / adjusting
 

Sorry I never asked what combo and class do you run? Ed

Re: Ladder bar tuning / adjusting
 

I run nostalgia SS and FX stuff........not current traditional stuff like you're doing but fun none the less......still a lot of work though , mainly because I do everything myself , engines , trans , rear end etc etc........and the body aint what it used to be and is very sore at the end of the day.
A 377 is in the car now but I've been a 9.41@ 141 with the ol' 355......but that engine would vary from that best to a low .60 high .50. 23 degree std runner head.
The 377 is the same engine basically , just the 4.155 bore and more compression. Same heads , cam , intake etc etc.
This is an old video..........I've posted here before , but here it is ..this was with the 355......9.51, 139ish. Launch RPM was realtively low this day IIRC
https://www.youtube.com/watch?v=EeHwn70US3g
I expect the 377 to get me in the 9.30s in good conditions.