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Are quad shocks wanted/needed with good suspension?

We have been running bilstein quad shocks with steeda upper and lowers. We are changing the lowers to MM Super heavy duty adjustables with polys in the back and spherical in the front. The uppers are Baseline suspension pro street launch with solids in the 8.8 housing and polys in the fronts. We have been considering a anti-roll bar as well. With this kind of a set-up, are the quads a good thing or bad thing?. Our tires clear them, so we can keep them, but didn't know if we should with all of the other stuff. Do you guys still run quads?
 

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Wheel hop comes from two things. One is the tires bouncing off and on the track, usually from a lot of power and very soft rear shocks or tire wadding.

The other more common thing is axle wrap. The bushings are soft, the axle rotates back at the top and forward at the bottom, and this changes the geometry causing it to lift the tires. As soon as the tires spin the axle unwraps, it regains traction, and then it wraps again. The shocks, unless staggered one front of axle and one rear, can't control this.

Ford added the quad shocks to dampen the axle wrap because they had to use very soft bushings in the upper arms to prevent binding.

If you get rid of the soft bushings and use heim joints at the floor and solid bushings at the rear end tabs at the top, and one set of heims and a solid bushing on the lowers, the rear end will move freely without binding and never wrap.

If you don't do that, you roll the dice on rear end oscillation as it wraps and unwraps.

Until I installed heims and rigid poly bushings in both upper and lower, I would occasionally get axle wrap without the quad shocks. How often depended on the traction and tires. Now with solid bushings and heims, I never get wheel hop and don't need the quads. The only time I get tire shake is when I run soft sidewall tires on a really tight track and wad the sidewalls all up. Like if a track is prepped for radials and I run old slicks at low pressure, my car will shake violently. Nothing cures that except enough pressure to get the sidewalls stiffer so they don't wad up.
 

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I haven't run quads in years. I've never had wheelhop except when the car was near stock on street radials, either. You do have to be careful with uppers, though - you can put poly bushings in one end or the other, but not both. The uppers tend to bind if the bushings are too stiff. I run (gasp!) factory uppers, with poly bushings on the chassis side and heavy duty rubber bushings in the housing ears. I count on the factory upper arms to flex a little to counter any bind. If you look at the uppers installed from underneath, it's pretty obvious why they would bind:



That's somebody else's pic (follow the link for credit), but you can see with bushings why they would bind. Heims wouldn't bind, but can be murder on torque boxes, and not a good choice for a street driven car unless your NVH tolerance is significantly higher than mine:


FWIW, I've run both aluminum and Megabite Jr. lowers. With the megabites, on tiny 8.5 x 26" slicks, I've gone 1.41 60' through a glide (1.80 gearset) with only 3.08 rear gears at 3,443 lbs (~3,200 rpm transbrake launch). I also only have an airbag in the passenger side rear spring, and a factory rear sway bar. Oh, and the rear shocks are 15 year old parts store cheapos. I'd imagine in a lighter/shorter mustang, mid 1.3's would be easy.

Car always launches straight and hooks hard. You don't have to spend a ton of money or get overly fancy to make things work.
 
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I have had one Nasty head cold XS or I would have already had the pics to you. Tire hopping and shake never happen with me. Just give me a day or 2 to recover. I have pretty much have sorted out all the things you'll be up against. Quads wont be needed.
 

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Discussion Starter #6
I have had one Nasty head cold XS or I would have already had the pics to you. Tire hopping and shake never happen with me. Just give me a day or 2 to recover. I have pretty much have sorted out all the things you'll be up against. Quads wont be needed.
I hope you get feeling better soon. There is a bunch of sickness going on around here. Take your time-No hurry on our end!
 
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