..and how can you prevent or minimize it? Case in point my friend and I installed a freshly rebuilt 10 bolt 3.42 posi in his 72 GS455 clone but at a slow roll if he nails it the wheel hop is terrible. From a stand still it is less likely to happen.
Good diagram regarding what happens here, this one is for a leaf spring car but the principle is the same for an A-body four link car because the lower arms are being pushed forward compressing the rubber bushings, while the top bars are being pulled compressing those bushings in the opposite direction. When the bushings have had enough, tire friction is overcome and the bushings revert to their uncompressed state and the tire comes off the ground. When the tire comes back down and gets a good bite again, the rear axle housing starts to wind up again repeating the whole cycle. http://www.competitionengineering.com/articles/chassis2.asp The problem is most often due to worn out bushings. New bushings and/or coil spring air bags are a frequent fix. "No hop" bars are also used, changing the instant center of the four links by raising the upper bar mounting point on the housing. Devon
Two different things going on. Factory control arms and bushings flex and return causing rapid traction/no traction cycle. Factory suspension geometry unloads rear temporarily, when it reloads it bites- causing it to unload again repeated in rapid succession.
Thanks for posting that explanation. Ok, so he is running box lower arms with no sway bar, but has poly bushings on the axle tube for the lower mounting point of the upper arms and I think rubber bushings everywhere else.
I ran into axlehop on my 72 when I had the rear lifted about 2" with spring spacers. It changed the geometry of the control arms etc. Lowered it back down, and the problem went away.
Looks like the next step is 'no hop bars' I pick that over replacing rest of the bushings because they won't sacrifice ride quality and it is a better bet on fixing the problem and they will also help overall traction.
Any recommended links to suppliers of no-hop bars with reasonable prices? Would the new poly coil spring insulators have changed the geometry enough to cause wheel hop? He got them from OPG I think.
Reasonable prices? You usually get what you pay for. I found that to be true with No Hop bars. I spent an entire afternoon fighting to install some Edelbrock No Hop bars I got from Sumitt. Summit took them back even after I ground on them. Bought the TA Performance bars and they went on in about an hour. They transferred just as quick to my 8.5 10 bolt. In my world, if I can't afford something, I save until I can. Just my .02
Thanks Larry, so what was the damage? Speedway (if they are still in business?) has a set of Lakewoods for like $190. http://www.speedwaymotors.com/Lakewood-GM-A-Body-No-Hop-Traction-Bars,18980.html So you remove the bushing from the axle then you need to add new bushings to the no-hop bars. Do the bushings come with the T/A kit and are they the same bushings as would go in the axle or just specific to the no hop bar?
Actually, never mind I got my answer from T/A's pdf catalog. Looks like $175 and includes the bushings. Not bad. Since we're on the subject, would this help in my case where I have an open diff? I could use all the traction I can get and sticky's are not worth it for once or twice a year, but these no hops, if they aid traction in general even if wheel hop per se in my case isn't the issue, i'd consider installing them on my car too.
175.00 last I checked, but I only have a 2007 TA catalog. I tried to look them up online, but that part of the TA catalog is not available. I can tell you that they are MUCH nicer than the Lakewoods. You remove the rubber bushings from the ears of the rear, then replace them with a soild aluminum bushing ( included with the bars of course). Then you have to drill a hole on each side in the rear end webbing. Not a big deal. Look in the pictures.
They push the rear end down on launch, so yes, they increase traction. Good luck launching on one wheel though.
LOL Yea well at least I've managed a 12.90 with one wheel so far. That's with a 1.80 60 foot time. There's potential there with one wheel. :Smarty: Don't forget, the more traction you get the more stuff breaks too. :error:
