Briefly, my set up is a street driven '79 regal with a stockish 455 and th400, and not much else, everything is mostly stock, except for stiffer rear springs and South Side Machine lowers. Rainy days have prevented the fronts from getting changed(stock v6 springs). So anyway, I've noticed at speeds over 30 mph or so when I let off on acceperation that the rear end seems to unseat and wiggle just a little bit as the weight is shifted forward off of the rear end. Same goes for slight braking. It's most noticable on bumpy roads at speeds where I may have to brake for traffic and what not. Then the car shifts and almost rear steers me in the lane. Needless to say this was a bit unnerving the first few times it happened. The swerving needs to be controlled because at highway speeds it has me all over the lane and I feel it is really unsafe. Courses of action? Would the addition of a rear sway bar help keep the side to side shifting at a minimum? Or at least provide some balance inthe rear? Would adding the stiffer springs up soon reduce the weight transfer? Would a rear frame brace help stiffen and reduce this too? I'm really up for just about any ideas. I'd appreciate any help. Thanks alot! Ryan
I think it sounds like the V6 springs under the heavier 455, plus the stiffer rear springs are causing the rear end to lift up and unload the rear end of the car, effectively causing the rear steer problem you speak of. The reason I suggest this as being the problem is because when I had the original, completely shot front springs, and front shocks that no longer had any rubber bushings in them... plus air shocks completely filled in the rear (previous owner did it, not me), I would have this problem under hard braking, like coming off of the highway. I went with Hotchkis springs at all 4 corners and the car is much more stable. I say get some stiffer front springs (stiffer than the rears, that is), and you should be ok. Personally, I'd go with something like Hotchkis springs (G-Body guys probably know more about those specific cars suspension setup and what works best)
Get those old v-6 springs out and put the v8 springs in, if you're primarily on the street, Moog's seem to be the best (spec with A/C to handle the weight) the other good aftermarket ones like Hotchkis or something from Performance Suspension in Arizona will work well, don't skimp on shocks either, gas only, and the best you can afford, Monroe Sensatrac's would be the lowest quality you want, Edelbrock IAS's are the best for the street. Once the new springs settle, then bring the rear to level with (or just slightly above) the front. Stock (with Airlift air bags) or stiffer (not taller) new springs will then balance out the setup, again, same shocks as the front, SSM or Metco lower arms do not like to be jacked on at rest (like station wagon coils or excessive rear lift) because of their dropped rear mount, they already act like a stock unit that's been jacked up, plus, the lower the rear suspension sits, the more stored energy it can apply to the pavement on a launch with the lower rear mount arms. :3gears: :Smarty:
