Rear end feels unstable
06-03-2012, 08:50 PM
#1
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Rear end feels unstable Mods:
New BMR lower springs
BMR Torque arm relocation
BMR LCA Relocation brackets (lowest bolt hole)
UMI Adjustable LCA's with poly and roto joint ends
UMI Adjustable Panhard with poly and roto joint end
Rear shocks = Koni SA 3rd gen (tried stiff to soft) feels rough/unstable
Factory rearend (6 speed car)
tires = 275/45/17
Any idea why the the rear of the car would feel real loose over bumps and turns and just not stable? It seriously feels allover the place, especially over bumps, everything is tight. I will say this, the LCA bracket's on frame of the car seem little warped, maybe causing slop in the LCA's themselves? Is this common at all?
Doesn't seem to be hitting the factory bump stops
New BMR lower springs
BMR Torque arm relocation
BMR LCA Relocation brackets (lowest bolt hole)
UMI Adjustable LCA's with poly and roto joint ends
UMI Adjustable Panhard with poly and roto joint end
Rear shocks = Koni SA 3rd gen (tried stiff to soft) feels rough/unstable
Factory rearend (6 speed car)
tires = 275/45/17
Any idea why the the rear of the car would feel real loose over bumps and turns and just not stable? It seriously feels allover the place, especially over bumps, everything is tight. I will say this, the LCA bracket's on frame of the car seem little warped, maybe causing slop in the LCA's themselves? Is this common at all?
Doesn't seem to be hitting the factory bump stops
06-04-2012, 01:38 PM
#2
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Wel its normal for the back end of the car to skip outward when hitting a bump in a turn. If you're sure that everything is tight then maybe the rear isnt centered?
06-05-2012, 02:19 AM
#4
Are you sure its not something with your tires? 275/45/17 is a bit tall for these cars, combine that with a mushy sidewall tire and you may feel some looseness. I can tell night and day difference when switching from 245/50/16 winter tires to 295/35/18 performance tires.
06-05-2012, 04:58 AM
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I think this would depend largely on setup.
If you are aiming for more of a drag setup it's going to be looser on bumps while cornering. In my experience even a car geared towards handling kinda skates on a washboard (multiple small bumps in a row) surface. But it grabs at the first opportunity and is predictable.
The biggest difference will be how predictable the car is. Multiple bumps during a corner should grab relatively quick everytime. A softer spring and shock is going to let the rear bounce more and may ultimately spin the car, but it will launch off the line better. Where a stiffer spring and more aggressively valved shock will handle the axle... at the expense of launching ability.
A taller sidewall also introduces another variable in that it flexes and bounces like a spring but with no shock to handle its behavior. So it bounces over the bumps unhindered causing the rear to skate around.
Having the LCAs level with the ground will help. Lowering the panhard rod with a bracket will help. But in the end you are going to still have to get used to the behavior of the solid axle in your setup.
In general we're going to need to hear a bit more about the car and your priorities to steer you in the right direction.
If you are aiming for more of a drag setup it's going to be looser on bumps while cornering. In my experience even a car geared towards handling kinda skates on a washboard (multiple small bumps in a row) surface. But it grabs at the first opportunity and is predictable.
The biggest difference will be how predictable the car is. Multiple bumps during a corner should grab relatively quick everytime. A softer spring and shock is going to let the rear bounce more and may ultimately spin the car, but it will launch off the line better. Where a stiffer spring and more aggressively valved shock will handle the axle... at the expense of launching ability.
A taller sidewall also introduces another variable in that it flexes and bounces like a spring but with no shock to handle its behavior. So it bounces over the bumps unhindered causing the rear to skate around.
Having the LCAs level with the ground will help. Lowering the panhard rod with a bracket will help. But in the end you are going to still have to get used to the behavior of the solid axle in your setup.
In general we're going to need to hear a bit more about the car and your priorities to steer you in the right direction.
