I bought better tires, redid the alignment and the problem went away. My car felt nervous as I drove home from the dealership too

Don't keep me in suspense, what tires, what alignment specs?

Firmer suspension will reduce the bump steer but will increase the bounce on very sharp bumps. How many miles on your tires? Might be time for a good alignment.

Yes, and yes. The change from full droop to body weight compressed is relatively minor, too, so most of the toe is getting dialed in on compression from rest.

I don't know wat happened on your car, but on mine the stock rear toe-in appears pretty aggressive as it is. 4K on the stock tires and 1/2 worn. I'd want more toe-in?

Redzed- I will need to check into wat you posted.

5K on the the original tires, the wear pattern is near perfect, no irregular wear.

A little context please: I've done a lot of reading on suspension design over the years and I know that bump steer is generally to be avoided. Since bump steer characteristics, on a production car, are rarely adjustable I have no practical experience altering them, so please help me out, is a 1/16" toe change (most of it on bump) considered to be a lot/excessive for a car such as the Z?

When contemplating the Megan Torque Arm as a possible solution:

1. Changing the inner pivot point (dropping it or moving it in a bit, probably not practical) could alter the bump steer profile.

2. Changing it's length (most likely longer) would reduce the angularity of the torque arm over it's length of travel which should "soften" or reduce the total amount of toe change. This assumes that there is enough adjustability in the torque arm to make a meaningful increase in length and enough adjustability in the rear suspension to bring the static toe and camber adjustments back into spec.

Comments?

I honestly don't remember off the top of my head. Alignment on new cars can be spotty given the abuse some of them had. I traded in a stock RX-8 that had Direzza Star Specs and a relatively tame alignment on it. The car handle corners with grace and had no drama. On the way back from the dealership, the Z felt nervous at the same exact speed on the stock RE050a. I immediately went out and bought myself a set of RE11 along with an alignment. I basically put together to 1/16 toe in in the front, about 2 degrees of camber in the back along with I believe about 1/8 in toe in in the back. The nervousness I had with the car was gone right after. Heck, it took me a good two years before I had anything close to a spin.

Interesting. Mine has been rock solid in all modes from the day I got it except for this one issue. That's the reason for my initial post, the apparent bump steer issue stands out because every thing else is so good.

I am choosing my words carefully here to avoid having them misconstrued by some of the overly sensitive members here, so the answer I will give is I believe so
I would agree with both of these. I also agree that the first is likely not practical.
I have no real experiece with the Megan arms, but I am always hesitant to use Megan parts. I know that a longer arm is needed to get good bump dynamic, but at the same time, I don't imagine you have the time/money to play around with a bunch of different parts.

If you do get the Megan arms, definitely post up thoughts though. I'd be curious to see if it sorts out the craziness (and it would be pretty helpful for anyone else that experiences it)

lame!! :bowrofl:

Lmao

Your caution is appreciated.

If can make this better I'd be happy to share anything that I learn.

Do you have any idea if the rear suspension has much range of adjustment, any feel if it could tolerate a somewhat longer (1", just a guess) torque arm without wholesale component replacement to allow proper alignment?

Something I should know about Megan?

I haven't spent enough time considering the swap to know what you can get away with, and I obviously don't have access to a z anymore, so you'll have to rely on someone else.


Megan is largely a knock off brand. Some of their products are fine, others are spotty. I try to avoid spotty suspension pieces.

Megan is a Taiwanese brand(?) They got the name from Mugen.

The above was posted with caution .