Rear suspension tech/info needed

4

4Eyedturd

Well Known Member
For you guys that race these cars, you’ve spent some time getting them dialed in. I’ve done some searching for help on wheel hop and found bushings, control arms, tires, or shocks to address. My car has had wheel hop since I’ve had it and I’ve made new rear arms out of DOM tube and poly bushings, changed tires, went to wagon springs and finally put in double adjustable rear shocks. It would wheel hop with 245 tires and now the wider ones. My thoughts were adding the 4th control arm to help control the rear end. After that playing with the control arm points. The lower arm has 2 holes at the frame and someone makes upper arm brackets to give you other holes to use. Then figuring instant center, bar angles, center of gravity and all that fun stuff.

I guess I’m kinda hunting for advice and any tips.
 
johnnyriviera

johnnyriviera

Well Known Member
Often wheel hop is something flexing or distorting until the tire breaks traction, then the process repeats over and over. Often seen on leaf spring cars. You didn't mention if the arms you made were upper or lower, if it was upper, box the stock lowers. I also agree with La Hot Rods about bracing that front crossmember as its can flex, and eventually rip out. The additional upper is a good idea. Once you are sure everything is not moving, then you can delve into the world of plotting instant centers and centers of gravity. Ride height can also play a big part of the angles. Generally, jacked up rear exasperates problems. Consensus is that the closer the lower arms are parallel to the ground the better, but I can say mine are not and the car has ran pretty hard off the line with a best 60' of 1.377.

Is the car manual or auto?
 
johnnyriviera

johnnyriviera

Well Known Member
I have never had wheel hop ever.......every other type of traction problem....but not wheel hop. I am not running anything super trick except the shocks, but everything is stiff and solid, that's what made me think of things possibly flexing on his car. Wheel hop isn't something you hear of a lot on these cars. Coil sprung Chevelles, yes, leaf sprung Camaros GOD yes, but full size, this is the first I've heard of someone having that issue.....but that don't mean much!

Now I've had the car hit the tires hard enough to crush the sidewalls of the slicks causing them to spring back and unload, which kinda feels like wheel hop. Fixed that by taking OUT some anti squat I had dialed in, and stiffening the extension on the rear shocks.

But it doesn't sound like he's running slicks by how he calls out the tire size, so guessing that's not the problem.
 
4

4Eyedturd

Well Known Member
Car is a stick and I made all 3 arms. First go around was on bald 245 drag radials. Just trying to do a decent burnout on the street resulted in violent wheel hop. This time is on a 315 street tire, rolling into the throttle in 2nd gear when boost comes in the tires get to violently wheel hopping again. I eased back home, kinda disappointed. I figured with 4.10’s and more power it would just blow the tires off.

I’ve got the Global West crossmember braces and control arm brackets on the way. They should be here before my next days off. For anyone that’s curious, Prothane doesn’t sell bushings for one control arm so I had to order a whole kit.
 
303Radar

303Radar

Well Known Member
Supporting Member 2
Did the wagon springs help or otherwise change the characteristics of the wheel hop?
Something is causing a load/unload of your rear suspension. I would expect the stronger springs to have some kind of effect, mostly good.
Also, curious if one side hops higher or more than the other.
Is there an engine rpm or vehicle speed this is happening at?
 
303Radar

303Radar

Well Known Member
Supporting Member 2
One option you have is to take a dash cam and securely mount it in various locations and see what is flexing and what isn't with a loaded suspension.
This should help isolate the root cause.
 
johnnyriviera

johnnyriviera

Well Known Member
Stick cars hit the tires hard. Slowing down (tightening) the extension (often called rebound) on the rear shocks can help. It slows down the hit, and spreads it over a longer time period. Doesn’t shock everything so much. Don’t be afraid to take a big swing, like 5-10 clicks. Just write down your setting so you can easily go back if you have to.

And as others said- pinion angle can play a part too.
 
benchseat4speed

benchseat4speed

Well Known Member
Supporting Member 7
The solution is cut all the stock stuff out and put a 4-link and coilovers under it but,

short of doing that....

Global West has everything you need to fortify and stabilize the stock rear suspension. Uppers, lowers, braces etc. Very good quality parts, made in The States.

1958-64 Impala, Biscayne, Bel-Air and El Camino

1958-64 Impala, Biscayne, Bel-Air and El Camino
www.globalwest.net

Also, I've read on here that at least one guy has broken a stock lower control arm mount off the frame. I never have, but they don't look strong enough to take a hard hit.
 
4

4Eyedturd

Well Known Member
BSL409 said:
I also did Similar to my 62 when first started to race bent both lowers inward. After I finally figured everything out my best 60FT was 1.32
And best with the 61 Biscayne was 1.28 60FT
Both stick shift.
Click to expand...
Holy guacamole, 1.28 with an X frame chassis that was made for a “smooth ride”. I’m curious what yalls lower arm frame mount reinforcement looks like.

My Global West braces made it in yesterday as well as the anti squat/upper arm mounts. They are beefy
 
Last edited:
You must log in or register to reply here.
Top