Ladder bar.... Easier to adjust,can let stock rear floor intact 4 Link.... more difficult to adjust,but more adjustment options.Floor must be cut I am leaning toward the S&W ladder bar setup with double adjustable 32 inch ladder bars and moly ends. I will also swap the panhard bar for a Track locator. My car will have all glass doors,fenders,bumpers (F&R) hood,decklid. I have 15x14 Buick Ralley wheels with 4 1/2 BS and I plan to use a Ford 9 inch housing.How do I determine the spring rate? They offer from 95#to 250 lbs. http://www.swracecars.com/store/64-72-Chevelle-OSCARItem_145=10-501.aspx
Pat This what I was told 4 link if you race alot of different tracks, that gives you the maximum adjustment. Ladder bar simple and quick. Hope this helps. Rick
I have had and raced both, in the same car. For 10.50 or slower, a good ladder bar with a track locator is just fine. If your going faster than that, then there is no question the 4 link is superior. The 4 link, with a wishbone locator allows the rearend to roll rotate, over track irregularities and at gear changes. The difference between the the two, in the same car, with the same HP, was very noticeable. Just driving in the pits. Consistancy was much better also. Whichever you decide on, make sure you have some type of anti-roll bar. When buiding a chassis, it's important to overbuild, because you never really know how fast the thing will be in the future. And it sucks to have a good motor, but a car that doesn't work well with it. I would only build a ladder bar car, if I knew I was building a budget bracket car, that would never go faster than 10.50. I work with and prefer Chris Alston's Chassisworks for rear suspension kits. ____________ Sounds like your not going to cut the car for big tires, and in that event, I would suggest that you put a full compliment of stock type rear suspension components in from HRPartsNStuff. There is no real advantage to a ladder bar setup for a 10-12" tire car, considering the parts available these days. I am currently building an fast street car, fully NHRA legal to 7.50et, and that's what it will have, with a mini tub and notched frame setup, for 12" MT Radial Drag tires. Goal for that car is mid 8's with a supercharged 540 BBB. JW
What are the determining factors of deciding the rear spring rate? I am guessing the car will be a 3000 lb car when all is said and done. If I can be consistent,10.00-10.50's will be about the range I expect to be in. I know from seeing several others (Doug H,Rick M etc) it takes alot more money to sustain the 9's or lower. Although I would like that, I will be happy to be in my goal area. I want to also build a 464-470 motor and add Stage 2 alumninum heads as well as big headers. after the car is worked out. That is a long term goal most likely 2-3 years from now..
Pat, I assume your talking coil over springs, with an adjustable spring height rear shock. If you go that way, start out with about 120 or 150lb springs, and then you preload those up with the adjustments. I used to run 95 lb springs in the rear of my backhalved regal, that car weighted 3100 pounds. Too stiff a rear spring will kill your chassis reaction. I found quite a difference in chassis reaction with the lighter springs, vs the 160 lbs ones that were in it when I bought it. The preload actually stores energy in the spring. A GS is a little heavier in the rear than my Regal was. We ran 120 lbs springs in George's tube frame GS, but that car was considerably lighter in the rear than yours will be, due to the alum tubs and floor. Before building your car, you should pick up the book "Doorslammers" by Dave Morgan. Here's the link to an interesting book and DVD combination. http://www.speedtalk.com/doorslammers_drag_chassis.html JW
Thanks for the dvd link Jim, I will get that and check it out to get the answers I have. I have been talking to some chassis selling places,S&W,Morrison an a local guy and its unbelievablw how much difference they have in opinions. For the price of the dvd/book it will be worth it if I can save the money and hassles beforehand..
For 90% of the average race cars out there a ladder bar is all they need.Speaking from first hand knowledge.We have gone a 1.17 60 ft on a true 10 inch tire mt 29.5 10.5 part # 3062s.This a 1200 hp deal best time was 7.96 at 176 at 3100 lb.It all comes done to shock tuning and total combination.If a guy sets the complete car up right crank center,weight bias etc a ladder bar is deadly consistant and easy to tune.Spend money on good shocks Koni Santhuff or Afco the rest are garbage imho. For a guy that doesn't have any knowledge of chassis tuning a 4 link is overkill.
