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Topic: FRONT SUSPENSION (Read 951 times)
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*DB*
Jr. Member
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Posts: 49
BigBlockDart.Com
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Yes, swapped to a Pinto front-steer R&P in a 70 Dart back in the later 80's. It'll work for a drag car if the engine is moved back far enough that you can raise the rack to control the bump steer & clear the engine's damper. It won't work on a street car because you can't get the ackerman corrected. Ackerman is turning the inside front wheel more than the outside wheel so that the front tires don't scrub. Another, bigger problem with uncorrected ackerman is that as soon as you start turning the steering wheel it wants to go to full lock/full turn on it's own, fairly ripping the steering wheel out of your hands if you're not expecting it!
Yes, we bent the steering knuckles out (& down to help bump steer) as far as we could trying to correct the ackerman, but they are too short & will hit the tires. Bill's front end is your best bet for a street car IMHO.
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DAVE V
Jr. Member
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Posts: 14
BigBlockDart.Com
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DO YOU ALL UNDER STAND THAT I WANT TO SWAP RIGHT AND LEFT LOWER BALL JOINTS WITH EACH OTHER WITH ARMS POINTING FORWARD, ALTER THE K MEMBER JUST ENUFF TO FIT THE RACK. WOULD IT WORK? HAS ANY ONE DONE IT?
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*DB*
Jr. Member
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Posts: 49
BigBlockDart.Com
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*DB*
Jr. Member
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Posts: 49
BigBlockDart.Com
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Yes, you can physically swap the lower ball joints, just like you can swap the spindles. This car drives just fineAS LONG AS YOU ONLY GO IN A STRAIGHT LINE! As soon as you try to turn, even in the pits doing only 5MPH, the steering wants to turn itself, with considerable force, to full lock. This is because the front wheels are turning at the same rate. In order for the front end to be correct, the inside wheel MUST turn more than the outside front wheel. That is "ackerman." If you draw a straight line from the outer tie rod ends through the lower ball joints towards the back of the car, those straight lines SHOULD cross each other AND the rear axle at it's center. This holds true for both front & rear steer. The front end above does NOT have correct ackerman. The lines from the outer tie rods through the lower ball joints do NOT intersect at the rear axle. I would NEVER drive this car on the street!! It would be flat out DANGEROUS! It would want to turn itself to full lock (full turn), no matter your alignment, no matter your toe-in, no matter your caster setting, if you were doing anything EXCEPT going straight! The above car is a drag race ONLY car. It is designed to go straight ONLY, & it does that well. Driving that car in the pits is, however, not easy & if you're not ready for it, it's downright dangerous! The owner nearly wrecked it the first time he drove it, & that was in the pits doing no more than 10 MPH!!!!
Please, read that Direct Connection racing bulletin (linked above) about front ends. It will explain, with drawings & illustrations, most of what's happening to your front end while driving. If you have trouble understanding the bulletin, read it a second & third time.
I built that car, for a friend, starting in 1987. The front end, as you see it now, was built around 1989. Since then there has been much "fine tuning" done to it.
Let me repeat it once more, just to be crystal clear: THAT STEERING SYSTEM IS NOT SUITABLE FOR A STREET CAR IN ANY WAY, SHAPE, OR FORM! It would be much easier to adapt a rear-steer R&P to these cars, or just bite the bullet & buy Bill's Alter-K. There's a reason his front end costs what it does. Most of that reason is the engineering that went into it so that it would be a SAFE driver. I've talked with Bill a few times, & he admitted he tried to retain the stock spindles & lower ball joints while converting to a front steer R&P. He said it couldn't be done. I say it can't be done. That's why Bill uses Pinto/Mustang2 steering components & spindles: Correct ackerman.
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69 GTS Clonvertible
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Like I tried to tell you before you need to look into a unisteer unit that will be placed at the back of the K-frame. They make this setup for B and E bodys already...........calling them to see if they can make a custom rack for your car would be the easiest thing to do and cost you about $1,200.00, if you are conserned about price it looks to be cheaper than the Alter-K, but I still would rather save up to buy me one of Bill's setups, which have been engineered to use the rack up front like you are talking about, but I'm sure the ball joints that are used, are not stock Mopar. Oh and by the way please quit yealling in CAPITAL LETTERS. Unisteer setup  RMS Alter-K-tion  |
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Bakaruda
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I seen this one yesterday. Not impressed with the Unisteer. It looked like it would cause some oilpan issues.
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Cary Snyder
5.7L Hemi Cuda
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*DB*
Jr. Member
Offline
Posts: 49
BigBlockDart.Com
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OK, since we determined your intent (for a drag car that won't see any street miles), then I'll say that this will work, but there's something else that will cause you big trouble: If your engine is in the stock location, you can't mount the R&P high enough (& you can't move the outer tie rods down enough, they're still too short) to get the bump-steer under control. Seems you'll have a small issue with the engine balancer & rack wanting to live in the same place. The reason it's not an issue with the car I pictured is because the engine was moved back some 3"-4" when the front of the chassis was done, then moved back again at a later date (it's now some 7" back from stock). FYI, it's a 70 Dart. Engine is a 499" low block, 'glide, Dana on ladder bars. Runs in the low 9's at the high 140's (best time is a 9.0something at 149 usually runs high 9.1's to low 9.2's). Chassis is heavy (there are just a few extra bars in it) at around 2800 lbs, but after 20 years it's consistent & predictable.      |
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bigtimeauto
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*DB* let me ask you a question. Just a thought here If you were to mount the rack say 3" forward of where the outer tie rod ends bolt up this would give you some of what your looking for with the ackerman (probably to much but you get what i mean). yes? no? maybe?
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Bill_Reilly
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Actually, mounting the rack further forward amplifies the opposite affect, turning the outside wheel more. If you look at any pictures of prostock cars, you'll see the rack is really out in front to clear the big engines - these cars are completely unstreetable, but since they barely ever turn, it doesn't much matter.
You can play with this behavior using strips of poster board and stick pins. Its actually a fun exercise to see how the spindles steer differently as you change parts.
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Those who say it can't be done, should not interrupt those of us who are doing it.
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Bill_Reilly
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Those who say it can't be done, should not interrupt those of us who are doing it.
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bOb shingler
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DAVE V did you get my e-mail?
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"bOb Built" (no matter how many times it takes)  |
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bOb shingler
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strange246 will post them here for you.
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"bOb Built" (no matter how many times it takes) |
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Pages: [1] 
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drag link.JPG
