Wheel Hop

[rccktmn2]

First off the GM 4 link rear suspension is not designed correctly to plant the rear tires and eliminate the wheel hop. If you take the upper rear control arms and the angle they are on they never cross the parallel line of the lower control arms. If you put in no hop bars or something similar it will raise the upper control arms making them intersect the parallel line of the lower control arms and essentially trying to pick up the front of the car on take off eliminating wheel hop.

I know what you are saying sounds logical geometry wise anyway.... but from my personal on track experience I have to disagree. The no hop bars did not work for me. The car was inconsistent as hell with the no hop bars and rode like sh*t too. I took them off, with no other changes, and the car worked again.
My suggestion to the question first would be to put new shocks on the rear. The rubber bushings couldn't be helping either. My car 60 foots in the low 1.40's with the stock geometry suspension setup. Over time I did add adjustable upper and lowers but they are set exactly like the stock ones that came off. Only difference being that they are now solid verses having bushings in them. I am also running a pair of $20 dollar gabriel shocks.

I agree with the rubber bushings because as soon as you put torque to them they flex way too much and I agree every car is different but I've seen some dramatic improvements just by changing the angles of the control arms on the rear.
http://www.baselinesuspensions.com/info ... ag_Car.htm
Here's a website that explains all the geometry of the suspension, Dave Morgan also wrote a book called door slammers that explains it as well and if you check out most of the tubbed or non tubbed 4 link setups you'll find the upper control arms are pointed down in the front toward the front of the car and the bottom control arms as level as you can get them or slightly upward to get the most weight transfer you can to eliminate the wheel hop and plant the rear wheels.

 

[jrm81bu]

as far as I know wheel hop is created by the wheels moving forward and back...with leaf suspension the axle rolls forward twisting the leaf and then it snaps back causing wheel hop. The G body has solid links so unless the bushings are shot and/or the shocks are shot there is no reason for wheel hop on a G body. I know guys with GN's with stock set up in the rear do 11 sec runs and they have no wheel hop

You would think the links would be solid, however the u-channel shape of the control arm will still allow them to flex. Ultimately the flexing arms end up doing the same thing as the leaf springs wrapping.

 

[pontiacgp]

as far as I know wheel hop is created by the wheels moving forward and back...with leaf suspension the axle rolls forward twisting the leaf and then it snaps back causing wheel hop. The G body has solid links so unless the bushings are shot and/or the shocks are shot there is no reason for wheel hop on a G body. I know guys with GN's with stock set up in the rear do 11 sec runs and they have no wheel hop

You would think the links would be solid, however the u-channel shape of the control arm will still allow them to flex. Ultimately the flexing arms end up doing the same thing as the leaf springs wrapping.

I'd have to agree with you on the control arms flexing and I didn't consider that to cause the wheel hop. I think that if the lowers have a sway bar mounted on them that would stiffen them up but they still ought to be boxed. The uppers still need to flex to deal with binding issues so I guess the uppers should be changed to set with a bearing on one end so it won't flex or bind..

 

[shanghaismith]

I had real bad wheel hop. I boxed the lower control arms and installed some relocation plates I got from UMI, spent a total of about $90, problem solved. I have the regular rubber bushings, in good shape. My 60' times are around 1.90