Handling issues, Please help!!!!

[ikle]

Like I said, dissconnect your rear sway bar and drive it then tell us how it feels.

dsapper I disconnected the rear swaybar and drove it,the problem got worse. Whats the next step ? Thanks, Kyle.

 

[scot w.]

Scott its a 1 1/8" bar with end links located in the first most forward hole. I had this problem before I installed the DSE bar when I was running the stock bar.

Okay, Well now at least you know your rear sway bar rates! Hopefully between us here we can get the problem solved soon....

 

[ikle]

Okay, Well now at least you know your rear sway bar rates! Hopefully between us here we can get the problem solved soon....

Thanks Scott, I think its spring related though, the problem started when I replaced the rear springs and upgraded my stock upper and lower control arms with Metco's adjustable uppers and billet aluminum lowers.

 

[dsapper]

Worse?! Ok, so when you go around a corner to fast the rear end slides out correct, like your trying to "drift"? I just want to make sure we have the terminology correct. Something is going on because going from no sway bar to a big swaybar I have no idea how oversteer could get worse.

Now understeer could get much worse by removing the sway bar. Its when the vehicle wants to turn too far, with the back end sliding around and, in extreme cases, trying to pass the front. An oversteering vehicle feels like it's about to spin, and frequently does if the driver isn't skilled enough to "catch" it.

 

[ikle]

Worse?

Now understeer could get much worse by removing the sway bar. Its when the vehicle wants to turn too far, with the back end sliding around and, in extreme cases, trying to pass the front. An oversteering vehicle feels like it's about to spin, and frequently does if the driver isn't skilled enough to "catch" it.

Yes,I believe its an understeer issue, it does exactly what you said. What would be the next step ?

 

[dsapper]

ok, well you have been going the wrong way. You started out telling us it was oversteer so we have been leading you down the wrong path. Understeer is dangerous and not at all fun lol.

Do me a favor, google oversteer/understeer. Lets make sure 100% you know which one it is because they are polar opposites.

 

[ikle]

Do me a favor, google oversteer/understeer. Lets make sure 100% you know which one it is because they are polar opposites.

Googled
1) over steer: the car turns more sharply than intended and could get into a spin.
2) under steer: the car does not turn enough and could leave the road.
We have a winner its over steer, sorry for not knowing the difference. Thanks for your patience, Kyle.

 

[dsapper]

Wow, I'm surprised you survived the little no rear sway bar experiment then lol. No problem, just want to make sure I'm leading you down the right path. Ok, so basically the exact opposite of everything I said.

Adjust the rear sway bar for the most correction, not familiar with DSE but whatever the firmest setting is (scot will chime in I'm sure). I'm thinking a new alignment with increased front negative camber and positive caster. Your front springs may be to stiff or the rear to soft. Not sure what your brake situation is but if you have a proportioning valve, to much front brake can cause this. Also, to stiff of suspension or shocks can cause it as well as older, harder tires. To little suspension travel or a weird toe problem will cause it.

 

[charlief1]

When an understeer vehicle is taken to frictional limits where it is no longer possible to increase lateral acceleration, the vehicle will follow a path with a radius larger than intended. Although the vehicle cannot increase lateral acceleration, it is dynamically stable.
When an oversteer vehicle is taken to frictional limits, it becomes dynamically unstable with a tendency to spin out. Although the vehicle is unstable in open-loop control, a skilled driver can maintain control a little past the point of instability with counter-steering. However, at some limit in lateral acceleration, it is not physically possible for even the most skilled driver to maintain a steady state and spinout will occur.

Understeer is built into most cars so that you can't take a corner like a road racer. Easiest way to describe it is "nose dive" while you're hitting a corner. Now that we've got a better idea of what's going on you really need to get a better set up overall. I personally prefer a balanced or slightly rear biased car to be able to go through the corners a little easier. The variable rate springs are the biggest issue I see you having right now along with a stock front sway bar. It's very hard to determain what a variable rate spring will do under compression with out a special set up you can put the chasis on. That's just one of the reasons I don't like them for regualar cars.

In a racing chasis you can use a dual spring set up that will allow the lower rate spring to compress soild and rely on the primary spring in a corner. A variable rate spring doesn't work that way. It starts out as one rate and then as it's compressed the rate goes up exponetionally.(sp) What you're experiencing is the rate change as the spring is compressed and pushes back on the chasis. There's very little give as you hit the corner and the rear tries to kick out on you.

If you've ever gone to a dirt track race you see the guys in front using oversteer to go around the corners. The back kicks out and they counter steer to get through the corners.

 

[ikle]

Adjust the rear sway bar for the most correction, not familiar with DSE but whatever the firmest setting is (scot will chime in I'm sure). I'm thinking a new alignment with increased front negative camber and positive caster. Your front springs may be to stiff or the rear to soft. Not sure what your brake situation is but if you have a proportioning valve, to much front brake can cause this. Also, to stiff of suspension or shocks can cause it as well as older, harder tires. To little suspension travel or a weird toe problem will cause it.

After work I'll adjust the rear swaybar to the firmest setting, right now I am running caster L side +6 3/4 camber -1 1/4, R caster +6 3/4 camber -1 3/8 with toe being L -1/32. R- 1/32 in. What caster ,camber and toe do you recommend. Thanks again,Kyle.

 

[scot w.]

After work I'll adjust the rear swaybar to the firmest setting, right now I am running caster L side +6 3/4 camber -1 1/4, R caster +6 3/4 camber -1 3/8 with toe being L -1/32. R- 1/32 in. What caster ,camber and toe do you recommend. Thanks again,Kyle.

Are you POSITIVE the Camber & Caster numbers are right?

Here is what my car is aligned to and what DSE told the person to do it at...

Front
Camber: -1.2
Caster: 6.15
Toe: 3/32"

Front Total Toe: 5/32"
Steer ahead: -0.01 deg

Rear
Camber: -0.25
Toe: 1/16"

Total toe: 1/16"
Thrust angle: 0.03 deg

 

[ikle]

Are you POSITIVE the Camber & Caster numbers are right?

Here is what my car is aligned to and what DSE told the person to do it at...

Front
Camber: -1.2
Caster: 6.15
Toe: 3/32"

Front Total Toe: 5/32"
Steer ahead: -0.01 deg

Rear
Camber: -0.25
Toe: 1/16"

Total toe: 1/16"
Thrust angle: 0.03 deg

Scott I dont know if those number's are accurate, I did an old school alignment my father taught me years ago, I used a tape measure, string, a new caster /camber gauge and set of old turn tables. I did this on a level floor, going to see how accurate those numbers are when I bring it down to work and check the alignment on the alignment
machine. The car goes nice and straight, so first I want to resolve my rear issue, since it started before I even touched the front end. Thanks, Kyle.

 

[scot w.]

If this started Before you even done the front end & after you installed the upper & lower rear control arms then that is where I would focus on and look things over very well.

 

[RKHiPerformance]

If this started Before you even done the front end & after you installed the upper & lower rear control arms then that is where I would focus on and look things over very well.

The Metco arms install as direct replacements for the originals, and there is no way that proper installation of our arms could create the handling issue you describe.
I'll assume these Metco control arms were purchased new, and the length of the upper arms has not been changed. The upper arms are assembled at our shop to match the length of the original upper arms, so installation of the control arms will result in the restoration of the OEM suspension geometry.
If you purchased the arms second-hand, I would suggest verifying that the pinion angle is correct (about -2.5*), the locknuts on the control arm adjusters are tight, and that the bushings have not been abused.
I suggest verifying that the bushings in the axle housing ears were properly installed and are fully seated, and that the control arms bolts were torqued to manufacturer's specifications while the suspension was loaded with the weight of the vehicle. There's really not much more to it.
If you have any questions about our control arms or the installation of our arms, please feel free to contact me. I'd be more than happy to help you sort this out:
Rick@MetcoMotorsports.com
864.332.5929

 

[ikle]

Thanks Rick I'll give you a call, I believe I installed them correctly. I am begining to think it might be a spring issue. Thanks, Kyle.

 

[dsapper]

For a street car -1/2* camber, +5* caster and 1/16" total toe works very well, thats what I had mine aligned to.

 

[jdpolzin]

The Metco arms install as direct replacements for the originals, and there is no way that proper installation of our arms could create the handling issue you describe.
I'll assume these Metco control arms were purchased new, and the length of the upper arms has not been changed. The upper arms are assembled at our shop to match the length of the original upper arms, so installation of the control arms will result in the restoration of the OEM suspension geometry.
If you purchased the arms second-hand, I would suggest verifying that the pinion angle is correct (about -2.5*), the locknuts on the control arm adjusters are tight, and that the bushings have not been abused.
I suggest verifying that the bushings in the axle housing ears were properly installed and are fully seated, and that the control arms bolts were torqued to manufacturer's specifications while the suspension was loaded with the weight of the vehicle. There's really not much more to it.
If you have any questions about our control arms or the installation of our arms, please feel free to contact me. I'd be more than happy to help you sort this out:
Rick@MetcoMotorsports.com
864.332.5929

I have been reading this thread and was waiting for this responce. My double adjustable uppers had me chasing the same problems. It was simple fix to reset the uppers to stock lengths and then adjust from there, which solved the odd handling.

Rick, I normally set my uppers by leaving the right side loose and adjusting the pinion angle with the left arm only. Then adjusting the right to fit into place. Is this how you would suggest setting the pinion angle as well? I've heard several ideas but this way seems to be the more prevelant responce. Would you agree? I also set my pinion angle referenced off the oil pan flange.

 

[ikle]

Ok I set the DSE rear swaybar to its firmest setting and it made the car handle a lot better, but I still need a little more. If I put different rear springs of a higher spring rate will that help.Thanks,Kyle.

 

[ikle]

I also measured my ride height it goes as follows: LF 26 5/8. RF 26 11/16. LR 27 3/16. RR 26 7/8. I measured from the floor to the center of the wheel opening moulding. Tires all where the same air pressure. It looks like the RR is sagging a little so I guess I am going to need rear springs any way. Kyle.

 

[charlief1]

Before you buy springs check the body bushing Kyle. If they haven't been replaced it might be causing the low measurment.