hey everyone, so i finally got my car legal and on the road only to find a strange problem. basically, going down the road, when i let off the gas or goose it, the whole car kinda twists. not like corkscrew twist, but laterally twist. i've a 9 inch with ladder bars and 411s. oh, and besides the twist, theres a lot of wheel hop with burnouts. i dont have much experience with this type of setup, so im looking for any suggestions. thanks in advance!
Do you have sub-frame connectors? Roll bar/cage? Pick up a copy of Door Slammers the Chassis Book by Dave Morgan. Very good book which will help you understand how race car chassis and suspensions work.
The term you use "corkscrew", reminds me of how a unibody like the Maverick can twist without SFCs (subframe connectors). Then the term you use "lateral twist" makes me think of how a car acts squirrely when it doesn't launch straight. SFCs help all sorts of things, but the wheel hop makes me think of things like mentioned about pinion angle. Or possibly a weak/damaged leaf spring. I have seen leaf springs that looked fine when installed, but when unstrapped from each other and removed, they fell apart into little pieces. Individual leafs can be broken, but held together by one or ones that are not broken yet. Also, you say you have "ladder bars"... True ladder bars are a coil spring only part. If you use them on a leaf spring car, the suspension MUST be set up with a full floating axle housing so the springs and bars don't compete for control of the housing and bind everything up. So, do you have true ladder bars? If so, are they set up with coil springs or axle floater units between the leaf springs and axle housing? If not, are you calling what is commonly known as "slapper bars", ladder bars? Slapper bars must be set up just so, or they don't function properly either. If they are slapper bars, do you know for sure they were set up correctly. Slapper bars are very effective at controlling axle hop. So are ladder bars, assuming they are not binding the springs.
Something else - maybe. In addition to the above, another problem might be that your front end alignment has incorrect (positive camber) settings . . . bear with me. When the front of your car raises under acceleration, and especially if the shocks are worn, the front wheels will point inward like this: \ / (positive camber) making it very difficult for the car to track straight. Having said that, when the car is under braking, the wheels are like this: / \ (typical setup for strip-only racing applications). Actually the car would track much better this way than if the alignment were in spec. See www.desertrides.com/reference/images/terms/camber.gif I'm not saying that's what your problem is, but it sounds like you're describing what my drag car felt like before getting the alignment set properly. I just saw a picture of your car (http://mmb.maverick.to/showthread.php?p=506383#post506383).. Looking at your front right tire, it looks like you might be running Skinnies. The phenom of positive camber would be exagerated with those tires. Edit: You wouldn't be allowed to run Skinnies on the street - so you probably aren't running them, now that looks like a leaf stuck to your tire and not in the background, and I don't want to delete what I went through the trouble of typing out, so there. Further, if someone else went through the trouble of putting in a 9" before you bought the car, it might have a "full spool" (both wheels must turn in unison). Those make the car handle like carp and will exagerate any handling issues. I sure hope that's your problem after I typed all that. (It's more than likely just a low tire though. ) Good luck!
whoa! first off, thanks for the quick replies, thats a lot to take in. i've leaf springs on the car and sub frame connectors. i'm going to take a closer look today as to what else is going on there. better yet, i'll take pics and post em. one thing i do know, however, is that the bushings for the leaf springs are wasted. i would imagine that could be part of the problem? i need front tires and while im at, gonna get alignment as well. once again, thanks for the input, im ignorant when it comes to suspension.
Take a close look at how the springs are mounted to the housing. The u-bolts could be loose or the spring perches could be broken. If either of those occur it twists the car up pretty good.
What I see here is a ladder bar suspension with leaf spring 'sliders'. Or at least that is what we used to call them. This changes things slightly since we aren't talking about stock suspension. My first thought is from looking at the rust I would check to make sure that the sliders can rotate (on the horizontal bolts) and move. Maybe a few squirts of WD-40 would help. I would also check the front mounts of the ladder bars to ensure that they have free movement. Check to make sure the welds are solid where the front of the ladder bars mount along with the heim ends don't have play in them. Additionally check grab the leaf springs and see if there is any play in the bushings (probably not a factor, but if you are under there anyway check them out). Finally you might want to take a look at the shocks to assure that they are both similar in how much resistance they have and that they both have a full amount of travel. Basically you are looking for binding in any of these areas. What you've described is like one side is free to move and one side is binding up. If all of that checks out, then maybe you need to jack it up and see if the differential is working properly and not binding up. I am assuming that you don't have a spool or a broken axle. That's a long shot, but worth checking out. I expect some of the other guys will chime in with their ideas also. Let us know what you find...
