How much does the rear axle wrap?

[flyinlow]

Lets say a stock '70 RT Charger , auto., 3.55 with 275/60 tires and a healthy suspension. How much pinion angle change is there under hard acceleration? Anyone ever have a video from under the car?

[Dmichels]

I can tell you with a base model 68 charger with stock springs, a 4 speed, mild 440, and street tires. I could wind up the rear axle to the point it would snap the rear u joint

[firefighter3931]

With SS springs the recommended pinion angle is 5-7* nose down. With the SS springs you don't even need a pinion snubber because the front segment is so stiff. With an XHD spring you usually set the snubber up with 1.5-2in of clearance. The softer the spring, the more wrap you will experience. Of course traction and torque/horsepower numbers also come into play. 


Ron

[flyinlow]

If you started with 6* static . I am guessing under normal freeway cruise load it would  reduce 2-3 degrees. Wondered if it goes negative under full load?  If you are breaking the rear u joint I would think its well past neutral?

On my sons '70 It came with a 4.10 and a snubber. The springs where a mess so we installed new XHD springs , shocks and a 3.23 axle until we can install an OD. The 4.10 had an adjustable  snubber , but I did not transfer it to the 3.23. Need to check his angles and maybe put the snubber back on, although there are no wheel hop or suspension issues now at his current power level.

Thanks, Craig

[firefighter3931]

Hi Craig,

If there is no wheel hop i'd say he's fine as is. The wheel hop usually results when the front segment bends like an "S" under hard launches and snaps back. 

With new leafs and modest power it should work OK as is 


Ron

[cjw916]

My '68 Charger 440 4-speed 4.10 8 3/4" had LHS wheel hop until I installed new stock (not SS) springs & an axle snubber. I installed mine with 1-1.5" clearance. After, it just sizzles the skins with no drama. My friend swears he can hear/feel the snubber hit on his '69 Coronet 383 Auto car (SS springs). I can't feel anything, but I'm sure it helped w/ axle wrap. I've since installed Hotchkis rear swaybar (already had Hotchkis front) & Hotchkis Fox shocks, makes LURID drifting powerslides effortless, love the no-body-roll from the swaybar! My vote is Snubber + swaybar!

[Ghoste]

Traction plays a role too.  Skinny street tires on dirty cold pavement won't wrap the springs nearly as much as they same car with slicks on a warm surface.

[Brightyellow69rtse]

I modified my factory snubber to get it close to the floor. Id have to go look at it but I'd say its an inch or less from the floor.