Volvo Rabbit?? Wheel Hop!!

[ksgonzo]

Hey Guys:
I've been having trouble during burn out with my '65 122S. Yes.... I know it's over 40 years old but it doesn't have to handle as one that old !!!
The engine has all the IPD goodies plus dual Solex 44PHH carbs, electronic ingition, header and 2 1/4 exhaust.
The suspension has IPD poly bushings, springs and Volvo R Sport front shocks and Koni rears. Tires are 205/60R15
Every single time (except on cement or wet surfaces) I luanch, the rear begins to hop like a freacking rabbit !!!! It not only drives me crazy, but the supports on the rear axle for the torque arm have broken!!!!
PLEAZZZZZZE How can I fix this???
Thanks a lot

[Poik]

Is it lowered?

[ksgonzo]

Only as much as the IPD springs, about 1 in

[mikep]

You are soooo going to break more stuff. Not that I would do burnouts in a 122...OK, yes I would. I would do a burnout in anything.
See if there is any evidence of harsh movement at the axle to lower arms, or if the bushings have any funny markings. Are they all hard urethane?

Oh, and lose the silly fonts or I shall throw a pox upon your 122 and it will turn into a chevette.

[ksgonzo]

Bushings are fine, I placed them about a year ago.
They're IPDs poly bushing kit. All poly except panhard arm. Also being a '65 it has the week lame old suspension type... Can it be hardened in any way???

[rice killer]

brake out the welder and have at it, roll cage and some nice custom braces will handle beautifully

[240 JAH]

would adjustable torque rods help? and what about linking the rear with the front.. i forget whats its called but alot of hot rod guys do it. its like called tubing the subframe or somthing I cant remember but its suppose to keep the rear to the ground. maybe pan hard rods do the trick.. damn it why cant I remember my hotrod convo with the racing group

[Poik]

I'm going out on a limb here because I am not familiar with your suspension, but does it use lower control arms (aka trailing arms etc) to hold the axle to the frame? If so, I'm not sure if anyone makes these, but since your car is lowered, you may want to weld some bracketry onto the rear axle to lower the attachment point for the lower control arms ~1" or more. This will return your suspension geometry to stock and will help a LOT.

[djecko]

Originally Posted by rice killer

brake out the welder and have at it, roll cage and some nice custom braces will handle beautifully

What does a roll cage have to do with this? and braces?
hes got wheel hop not a flexing chasis.

[mikep]

Maybe it's reeeeally heinous wheelhop.

[ksgonzo]

Thanks poik!!!
I'm trying to place a picture of the rear suspension but it won't let me!! It says "You may NOT place attachments"!! What`s with that?!?!?
I found another thread with the picture: http://forums.turbobricks.com/showth...ight=wheel+hop
It's the first picture or Early Type...
Has anyone heard of Traction Bars?? They weld or bolt to the chassis and axle and eliminate wheel hop. But of course theres no volvo application for them Can they be adappted??

[mikep]

slapper bars are for leaf springs, ladders are for eliminating parts of a 4-link, and a snubber can limit travel. Look for bad or weak parts, box the lowers if they are bowing, etc.

[Poik]

The method I am talking of would directly apply to the "Late" style suspension, but because of the way your stuff currently mounts I'm not sure you will be able to do it very easily at all.

Here is a picture of a bolt-in bracket (red thing) I have on my Camaro to lower the rear control arm mounting point ~3". This gives my car an extremely good plant on takeoff, but feels a bit more wobbly in corners, something to consider. With your car lowered the angle of your control arm is really bad. I'm trying to find this simple animation of how control arms work, but can't seem to at the moment.

www.eric-o.com/images/camaro/DSC00159.JPG

[ksgonzo]

So by lowering the angle it becomes stiffer thus eliminating wheel hop ??
What if I just eliminate the poly bushings and weld the torque arm to the chassis and axle?? Would that be driveable??
By the way... awesome suspension and brake upgrades!!

[Poik]

I found the diagram I was talking about:


Edit: And no, don't just get rid of the bushings and weld stuff up . You want those things to move as freely as possibly with minimal bind, which is why rod ends are the best for performance. Poly is a middleground between quietness and performance.

[k4dje]

Originally Posted by Poik

I found the diagram I was talking about:


Edit: And no, don't just get rid of the bushings and weld stuff up . You want those things to move as freely as possibly with minimal bind, which is why rod ends are the best for performance. Poly is a middleground between quietness and performance.

Yea, lift the rear up MOPAR , If you have ever gone to a drag strip and watched a Mopar super stocker or just about any Mopar you will see the rear of the car lift up. Check your angles.

[Renny_D]

I was looking at the diagrams and it looks like the old 122s had the torque rod at the same level as the axle. Making a torque rod mount to an arm about 2 inches above the axle instead of on the same plane as the axle should solve it but you'd have to lenthen the Torque rod to keep the pinion angle the same. Even 1 inch above the axle would be a big help. In front and on the same plane as the axle is the worst place you could have it. Do that and lower the trailing arms back to stock and you'd have nice solid axle positioning and no wheel hop.

Extreme 4x4 had a nice bit of software that predicts axle wrap and squat based on links and location on the axle. Here's the link http://www.xtreme4x4tv.com/news.aspx?iid=5023

Good luck and let us know how you fixed this. They used to race these dang things they must have solved this at some point in the past.

thanks
Renny

[Poik]

Originally Posted by Renny_D

Good luck and let us know how you fixed this. They used to race these dang things they must have solved this at some point in the past.

Not the 122, but this is what I just found about the Group-A 242:
"GpA rear end - ZF diff with oil cool system, lowered control arms"

[745 TurboGreasel]

Put on some tires from 1965, and I guarantee they will not hop.

[smosit]

wouldn't the open diff be part of the problem too? the rod allignment explination makes sense, definitely. but the hop is also (somewhat) from power being shifted--back and forth--from one wheel to the other--rotational momentum breaking the stationary wheel loose as soon as the spinning (lifted) wheel hits the ground. the trailing rod/torque rod mounts should be stout enough. a guy named Joe Derks had a similar problem with his hot-rod volvo (http://www.volvoadventures.com/1800Espec.html) and if i remember right he solved his problem by putting in an LSD. finding an LSD for the dana 27 will be difficult and even if you do, the tapered axle shafts in your 122 are a weak link too. if you get a rear axle from a '70-'73 1800, it'll have a dana 30 (many LSD/locker options), rear disc brakes, stronger axle shafts, and it should bolt in without modification.

good luck,

[mikep]

Usually, hop is from the axle dancing up and down like a hula hoop, whether open or welded or posi.

[ksgonzo]

Thanks Guys!!
poik: That diagram is worth a thousand words!! Explained things great!!
smosit: I think the diff has something to do as well, especially when I enter a curve real hard, the inner tire hops!! I know the 123Gt came with LSD, did any other volvo from the 60-70 era??
Turbogreasel: On the originals 165/80R15 launching was no problem but I had no grip when cornering, it was actualy fun to drive on those skinny tires but made it difficult on Auto-X

I guess I'll lower the arms and see whatr happens.

Thanks again you all