I don't like electric assist stearing.

Did you try increasing the front tire pressures as I suggested to you last week? For the 3.0 stock cold pressures are 33F, 36R and for the 2.5 they are 30F,

Tom K.

That was my fix as well. I've also heard of people increasing the negative camber or adding a strut brace. epbrown

I don't see how adding braces would change anything. Sell the car and buy one you like to drive. Oh, and test drive the next one.

Thanks for the help homer.

Oh, I did. But it is difficult to get a real good feel for a car in just a

I did and it helped a little. I am thinking the tower brace as well getting rid of the ride flat tires may help. But I am not going to swap tires just yet.

And I would not expect too many complaints on this board.

Braces will reduce flex on hard corners thereby keeping more tire on the road and improving cornering performance.

Do you mean that the car actually understeers or that the steering doesn't turn as much as you would expect?? if the former then I don't understand what the electric assist has to do with it. On my old 3 new decent tyres and then some eibachs solved any (unreasonable) understeer.

It's the later.

Undoubtedly true. But that was not your initial complaint. You said you did not care for the feel of the electric assist. Reducing or eliminating chassis flex will help reduce understeer, but not really change the feeling of the electric assist.

Then as E Brown suggested to you last week, you want a quicker steering ratio. Even if that was an option, you'd probably find that the car then would tend to wander more at freeway speeds, as the steering ratio is a compromise between low speed maneuverability and high speed stability.

BTW, changing your tires will likely have little effect since the OEM RE050 tires are pretty good handling tires. I switched from the Bridgestones to Goodyear F1 GS-D3s mainly because of lower cost and an improved ride - but IMHO, the Bridgestones handled as well as the Goodyears.

Of course, you could always have the steering & suspension checked out by a dealer in case something is out of spec - but the fact that the steering assist is electric doesn't seem to be your problem.

Tom K.

I guess I should have been more explicity. The "feeling" I was describing was understeer. Another description might be sluggish (not unresponsive but not quick). I realize it is better than found on a SLK but is not as good as a Boxster or Miata.

When I went to run flats to non-run flats on the Mini S it was like going from night to day. Much much much much better handling and of course the noise difference was huge (something not mentioned in this thread).

BWT, I increased the pressure in the front tires by 2psi. What would you recommend?

I have a feeling that you are misunderstanding and misusing the term "understeer", which may be leading to a lot of the confusing answers that you are getting.

Understeer is the condition that occurs during cornering where the car wants to "push out" the front end, pointing the car toward the outside of the corner. In essence you are "under steering" the corner. Oversteer is exactly the opposite, where the rear end kicks out and points the car toward the inside of the corner.

These have mostly to do with chassis balance, weight distribution and dynamic weight transfer during cornering. It has very little to do with the amount of steering "power assist" or the steering ratio.

From a review:

"In fact, if there's a fault to be found with the Z4's handling, it's the opposite: The rear sticks longer than necessary (read "understeer")."

From another review (this happened to me):

Out on the fabulous Jerez circuit, the dull steering doesn't really dent your progress, but the Z4 M's quite pronounced understeer does. If you misjudge your entry speed it's not easy to rein it in and exit the corner cleanly. Through the slower corners particularly you have to work hard to keep it neat and tidy.

Yes but you say the problem is the wheels don't turn as quickly as you want them to, not that the front end was losing traction.

I never said the front end was losing traction. I described understeer ("That almost happened to me. I came into a corner a little hot, I turned the wheel and then had to quickly compensate for the understeer.") . Now I think the electric assist steering is not the problem. The problem is the way the car is set up.

From another review:

"Basically, it is tuned to be an inherent understeerer. Always understeer, understeer and understeer. Whenever you push it harder and faster, understeer will get into the picture. The harder it corners, the more understeer it shows. Now we don't know why BMW needs rear-wheel-drive and an engine locating behind the front axle to create an understeerer. "

Frankly I am surprised this has not been discussed in the forum before. Maybe people don't recognize it for what it is or maybe they don't drive the car hard enough to realize the problem.

"grinder" wrote

It's been very well discussed that BMW sets up their cars (indeed, *EVERY* car manufacturer does this) for understeer as the primary response, because it's *generally* safer for most drivers. Even cars whose basic design (rear or mid-engined) would be expected to exhibit oversteer have tuned their cars to exhibit understeer.

You just haven't looked for articles discussing this.

FloydR

Well the understeer is the front end losing (some) traction. The process of hard cornering doesn't change the steering geometry so much that it doesn't steer enough.

Almost all cars will have that characteristic if you barrel into a corner, it's simply physics. You can reduce the effect by tweaking the suspension, springs, dampers, anti-roll/sway bars, different tyres etc etc.