Hey guys I just installed a new coil over kit that included upper/lower rear control arms. The rear is super bouncy when driving on uneven surfaces. I did not reinstall the quad shocks as I understood that with upgraded control arms they aren’t needed? Any help would be greatly appreciated to help me figure this out
New coil overs installed
- Thread starter GSnerraf
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Bouncing can be a spring that overpowers the selected shock. Need to know what your parts selection was. Please list all the parts you installed
Here is the link to my setup
Compatible for Ford Mustang 4th 94-04 Adj. Height and Mounts / Rear Control Arm Coilover Kits
Application Compatible for Ford Mustang 1994 - 2004 Specification Quantity: 2 piece front + 2 pieces rear + control arms as pictures show Spring rate front: 8 kg/mm (448 lbs/in) Spring rate rear: 7 kg/mm (392 lbs/in) Adjustable damper: No Adjustable height: Yes (front 485-575mm, rear 550-600mm)...
www.godpt.com
Those are some pretty high spring rates. My guess here is that the dampers just simply can't handle the rates.
I'll be honest. $600 for full coil-overs and rear control arms? This is just one of those times where you get what you pay for. If this was a kit like maximum motorsports i would recommend different spring rates (less) or a higher quality damper with perhaps adjustable settings. I don't think there is anything that is compatible with that setup.
I'll be honest. $600 for full coil-overs and rear control arms? This is just one of those times where you get what you pay for. If this was a kit like maximum motorsports i would recommend different spring rates (less) or a higher quality damper with perhaps adjustable settings. I don't think there is anything that is compatible with that setup.
rednotch
Founding Member
You bought a generic coil over kit that is made with absolute junk parts by a tawain company that cost about $200 and gets rebranded and marked up by all the parts hawkers shops., sve, Sr performance, maxpeeding, race land, bc racing and countless eBay drop shippers etc all sell that pile of junk. Any kit that uses that rear spring design is coming out of the same factory you can get them for as little as $300 to over 1k depending on which company brands it but its all the same junk.
The shocks and struts are garbage at best, the rear springs in that design will ride like trash and the bushing in those control arms will split and fall apart the second they see any kind of torque.. I would try to return it if you still can and go with something all ready proven for what you want out of your car. That kits for the parking lot, broke want to be drift crowd who just want it low and care less about function.
Cheap chinese sourced parts have there place, suspension is the last place you want them.
The shocks and struts are garbage at best, the rear springs in that design will ride like trash and the bushing in those control arms will split and fall apart the second they see any kind of torque.. I would try to return it if you still can and go with something all ready proven for what you want out of your car. That kits for the parking lot, broke want to be drift crowd who just want it low and care less about function.
Cheap chinese sourced parts have there place, suspension is the last place you want them.
Won't comment on the coil over kit, but I was also wondering about his tires. If you have a very stiff spring rate and a soft sidewall tire, your tire effectively becomes the spring (since it will compress before the spring when you hit a bump). I am not saying stiffer tires is the answer, but may help explain the bounce? What is your tire pressure?
Lower spring rates, or better shocks really.
What's happening is the spring is stiff enough that when you hit a bump, it wants to push down on the suspension very quickly and firmly. The shock is not controlling the impact so it overshoots and then relaxes which is creating the bounce effect.
You either need a weaker spring that the shock can control better, or a better shock that can react quicker to stop the suspension movement. The latter is going to create a VERY firm ride with those spring rates. Unfortunately that kid doesn’t really have options available in terms of other springs or shocks.
Street car rates for coil overs are typically 250-325# front, and 150-175# rear. That kit is 450#front/400# rear which is pretty damn stiff. That's road course stiffness there.
I hate to say it but there's not much you can do here. I also don't think that kit has a stellar rep for longevity.
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rednotch
Founding Member
Without putting better shocks and a much better spring design in it no, the only thing that kit allows you to do is adjust ride height, some of those kits have adjustable struts and shocks as options but the valving is garbage, the rear spring on those kits limit travel way to much.
rednotch
Founding Member
Name brand also has nothing to do with it RTR hawks that crap to because there one of his sponsors and there target market is the looks/drift crowd... If you want a good suspension for what ever your after be it comfort, handeling or dragracing go with proven parts and companies. This is a lesson most people end up learning, the aftermarket will sell you junk if they can make money on it.
Not with the parts in that kit.
That's what these guys are trying to tell you. The spring rate is [WAY] too high. Like a half-ton pickup high.
Unfortunately not. It won’t change what needs to be changed.
Really the solution is learn to live with it, or start from scratch with a different suspension setup
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