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WAY Too Much Oversteer, Help Me Sort it Out

Old 10-31-2011, 04:57 PM
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Originally Posted by jacob300zx View Post
Your other car is awd? You might just be a big *****
First thing that came to mind for me. Everything seems right in line for a very good set up. 1/16th toe in on the rear and some seat time in those lovely mtn roads you have may do you a lot of good.

It's a miata. You should be driving it, not letting it drive you.
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Old 10-31-2011, 05:24 PM
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Originally Posted by Bob Loblaw View Post
First thing that came to mind for me. Everything seems right in line for a very good set up. 1/16th toe in on the rear and some seat time in those lovely mtn roads you have may do you a lot of good.

It's a miata. You should be driving it, not letting it drive you, unless you are in Russia.
Corrected for ya.
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Old 11-01-2011, 10:29 PM
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Old 615's are a bear to drive on when cold. They are like trying to steer on ice. My last AX I kept dropping the rear tire pressure. 29psi hot seemed to work best on the rear.
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Old 11-02-2011, 04:21 PM
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+eleventy New tires will just hide the imbalance so that it only happens at a more dangerous speed. You would be far safer finding the deficiency first, whatever it may be.

It's a shame you can't mount a video camera in a position that would capture the suspension movement in action. Or can you?
This is a primary concern.

First thing that came to mind for me. Everything seems right in line for a very good set up. 1/16th toe in on the rear and some seat time in those lovely mtn roads you have may do you a lot of good.

It's a miata. You should be driving it, not letting it drive you.
I'm planning on going to the speed ventures autox at fontana the 19 of November. No working, unlimited runs for $55. If anyone is willing to share some seat time, I'll take whatever instruction I can get. I realize that I'm green in a RWD car.

I drive up and down the mountain twice a week, usually at 7or8/10s. I don't slide it around though, not the right place for it.
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Old 11-02-2011, 05:40 PM
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turn in early! go into the slaloms accelerating. either go in slow and get out faster, or go in fast enough to keep maintenance throttle. whatever you do, don't get on your brakes and accelerate a lot in the slaloms (you will get away with it a couple of times, but once you will find your *** spinning).

don't chicken out on the lane changes, its where the miata is star. You can use some trail braking to help you rotate in the chicago boxes. that will just take some ***** and practice to get it right (Go in "too fast", apply some braking, then turn, accelerate).

that's about all i got...oh, don't do back-to-back runs or you will over heat your tires depending on track length.
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Old 11-06-2011, 08:36 AM
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Pretty much echoing everyone elses advice here: check alignment, run softer rebound in back, disconnect rear bar, make sure you have enough travel so you are not bottoming and causing springs rates to infinity. One other thing to check is how soft is the suspension movement (without springs of course). Maybe something went wrong during the ES bushing install and is causing suspension bind which adds quite a bit of spring rate. Also, could you be lifting the rear tires? Did you hear the revs go mad under accel in a turn? Not that it pertains to you as you have Koni sports but a lot of the Koni race autox guys experienced issues with the shock not having enough droop and causing the rear tire to come of the ground and spins were almost certain. Maybe if the spring is not fully seated under full extension and with too much rebound damping you might be lifting the wheel?
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Old 11-07-2011, 05:39 PM
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+1 on the bushings. I had binding bushings on my race car and it was undrivable. Some understeer but mostly mad oversteer and all kinds of psycho habits. Now, there are grades to everything, but IMO one can make many bad settings on a Miata before you get a properly, madly badly handlig car.

My advice: Take a few minutes and remove lower shocks bolts and see how freely the suspension arms move. Idealy, they should fall down by their own weight. Bets of luck!
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Old 11-07-2011, 05:49 PM
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Originally Posted by Torkel View Post
+1 on the bushings. I had binding bushings on my race car and it was undrivable. Some understeer but mostly mad oversteer and all kinds of psycho habits. Now, there are grades to everything, but IMO one can make many bad settings on a Miata before you get a properly, madly badly handlig car.

My advice: Take a few minutes and remove lower shocks bolts and see how freely the suspension arms move. Idealy, they should fall down by their own weight.
Bets of luck!
Yep, I didn't notice this on the first page. If you tighten the bushings or coilovers down when the car is unweighted, it will make the ride a lot more bouncy and weird among other things. The ES bushings are pretty good about this, because the sleeve isn't connected to the poly like the stock rubbers, but I think you could still preload them if you torqued it down when it was unweighted. Thats something to check. As a reference, my ES bushings will drop by their own weight when the shock is disconnected.
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Old 11-08-2011, 02:33 AM
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Originally Posted by Track View Post
Yep, I didn't notice this on the first page. If you tighten the bushings or coilovers down when the car is unweighted, it will make the ride a lot more bouncy and weird among other things. The ES bushings are pretty good about this, because the sleeve isn't connected to the poly like the stock rubbers, but I think you could still preload them if you torqued it down when it was unweighted. Thats something to check. As a reference, my ES bushings will drop by their own weight when the shock is disconnected.
I guess ES stands for Energy Suspension? Same bushings as I have? There is no such thing as preload in these bushings. The bushing parts are fixe0d and the metal sleeve rotates inside them. You can insall them in whatever position you feel like. However, since they are made out of much firmer material and with no play, it doesn't take much for them to bind.
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Old 11-08-2011, 10:36 AM
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preload, bind, whatever you want to call it my friend.
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Old 11-08-2011, 01:33 PM
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Originally Posted by Track View Post
preload, bind, whatever you want to call it my friend.
Sorry if I come on like I dick here, but to make sure the OP gets the right info to help to fix his car: Bind and preload isn't the same thing. An OEM bushing that is torgued down in the wrong position can have a preload, as in "being in its loaded state when the car is standing still". ES bushings can bind, as in "not moving as freely as is should and therefore hinder the movement of the suspension arms". The ES-bushings can not, no matter when you torque the bolts down, have a preload.
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Old 11-08-2011, 02:04 PM
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either way, ES still says you need to torque all bushings down when under load, not in full droop.
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Old 11-08-2011, 02:13 PM
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as with any bushing.
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Old 12-08-2011, 12:23 PM
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Ok I got the time to do a little work the other day.

The rear has 7/8" bump travel before it hits bump stops.

The rear bushings may be a bit tight, or at least preloaded in droop. They fall slowly when disconnected, but it takes a herculean effort to push them back up. I know I torqued them to spec while loaded when I installed them. Perhaps the alignment guy just hammered at them with an impact wrench.

On another note, I think I ruined my new half shafts while installing my torsen. I was trying to remove the shaft from the spindle, got impatient/didn't have the correct tools, and smacked the end with a single jack a couple of times and mushroomed the end. Now the axle/spindle nut wont thread on. I'm looking into buying a new axle, but is there a cheaper solution? The threads aren't buggered, it's just mushroomed on the end, distal to the threads. I know it's probably some sort of hard alloy, but could I try to grind off a little bit to get the nut past the mushrooming? Is that dumb?
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Old 12-08-2011, 12:40 PM
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Originally Posted by dstn2bdoa View Post
Ok I got the time to do a little work the other day.

The rear has 7/8" bump travel before it hits bump stops.

The rear bushings may be a bit tight, or at least preloaded in droop. They fall slowly when disconnected, but it takes a herculean effort to push them back up. I know I torqued them to spec while loaded when I installed them. Perhaps the alignment guy just hammered at them with an impact wrench.

On another note, I think I ruined my new half shafts while installing my torsen. I was trying to remove the shaft from the spindle, got impatient/didn't have the correct tools, and smacked the end with a single jack a couple of times and mushroomed the end. Now the axle/spindle nut wont thread on. I'm looking into buying a new axle, but is there a cheaper solution? The threads aren't buggered, it's just mushroomed on the end, distal to the threads. I know it's probably some sort of hard alloy, but could I try to grind off a little bit to get the nut past the mushrooming? Is that dumb?
worth a try, if they are fubar'd after, then they were fubar'd before. I would use a dremel with a metal cutting wheel so its thin enough to fit.
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Old 12-08-2011, 01:43 PM
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Poly bushings don't have any preload. Rubber ones do.

If they are hard to move they are binding. Do a search.
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Old 12-16-2011, 05:12 PM
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RAISE THE REAR, 7/8" with that spring rate is not enough travel. When you get into the bumpstops your spring rate goes to almost infinite and you will get crazy oversteer.

Also in regards to shock adjustments, try this cheat sheet:

Adjust the end of the car with the issue first, when you run out of adjustment, adjust the other end (i.e. if the front is pushy, adjust the front)
Corner entry oversteer, remove Rear rebound OR add Front rebound.
Coner exit oversteer, add Rear rebound OR remove Front rebound.
Corner exit push, add Front rebound OR remove Rear rebound.
Corner entry push, add Rear rebound OR remove Fron rebound.
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