Today on a good clear section of motorway going uphill I gave my car a bit of the heavy foot into three figures where my car suddenly developed a slight side to side sway which started to get worse which I of course backed off. I recently changed my rear tyres to a different make from the fronts and have the rear strutt brace fitted.
Do you lot think it's the different brand tyres that caused this or something that needs attention to the car?
handling concerns
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hornel Z3M
- Joined: Sun 16 May, 2004 20:33
- Posts: 1120
- Location: RAGLAN
M
Bet it was the road camber. 
Z3M Handling
Loss of straight line stability at over 100mph sounds more like aerodynamics than tyre grip - was there a side wind?. The Z3M does lose rear downforce at higher speeds - the body shape and undertray create a slight lift.
I've found the car starts to feel less secure at high speed, but only really noticeable at over 125mph. Even at maximum speed the car is still quite driveable, although you need to concentrate. (I am, of course, referring to track and Autobahn experience!)
Having said that, I can't think of a good reason not to maximise the balance of the car by equalising the grip at each corner - not only the same make, but similar levels of wear for each tyre.
I can see the logic of the front strut - filling the obvious large gap in the car's structure, but I've yet to be convinced by the effectiveness of the butt strut. I have to say that I've only driven one car with it fitted (a Z3MC), which felt quite odd to me.
I've found the car starts to feel less secure at high speed, but only really noticeable at over 125mph. Even at maximum speed the car is still quite driveable, although you need to concentrate. (I am, of course, referring to track and Autobahn experience!
)Having said that, I can't think of a good reason not to maximise the balance of the car by equalising the grip at each corner - not only the same make, but similar levels of wear for each tyre.
I can see the logic of the front strut - filling the obvious large gap in the car's structure, but I've yet to be convinced by the effectiveness of the butt strut. I have to say that I've only driven one car with it fitted (a Z3MC), which felt quite odd to me.
There were no strong side winds and I've taken my car before to 130 where the steering felt extremely light and vauge to feel comfortable with so I'll get my fronts changed next even though there a good amount of tread left and fit my front strutt brace too. I was mulling over if all the bushes are letting the handling suffer as I've just clocked 67,000 miles.
Last edited by Althulas on Thu 17 Mar, 2011 15:36, edited 1 time in total.
Most cars begin to feel "light" in the steering and more vague / unsettled above 120mph unless they are designed to oprate at this speed effectively (most cars are a compromise and really balanced to perform best at road legal speeds). eg drive an F430 at 130mph it actually feels more stable, sucked to the ground.
As stated above what you experienced is more likely due to aerodynamics than tyres / suspension.
I'm fitting the Schnitzer splitters this summer and they really should make a difference at exactly those speeds as their purpose is to provide more downforce to the front end at speeds where you would otherwise experience lift / light steering.
It does make me laugh that spoilers / splitters have become such a cosmetic accessory with no consideration for what they actually do eg fitting a large boot spoiler actually decreases performance / MPG at legal road speeds and most of the cars with them fitted are not really capable of performing at the sort of speeds they were actually designed to operate
What you've basically experienced is the point where you have exceeded the cars standard aerodynamic performance peak but not he engines ability ie in theory if the engine was capable at some point on the scale the car would loose all stability (eg 200mph+)
As stated above what you experienced is more likely due to aerodynamics than tyres / suspension.
I'm fitting the Schnitzer splitters this summer and they really should make a difference at exactly those speeds as their purpose is to provide more downforce to the front end at speeds where you would otherwise experience lift / light steering.
It does make me laugh that spoilers / splitters have become such a cosmetic accessory with no consideration for what they actually do eg fitting a large boot spoiler actually decreases performance / MPG at legal road speeds and most of the cars with them fitted are not really capable of performing at the sort of speeds they were actually designed to operate
What you've basically experienced is the point where you have exceeded the cars standard aerodynamic performance peak but not he engines ability ie in theory if the engine was capable at some point on the scale the car would loose all stability (eg 200mph+)
You'll find that they make a real difference at relatively low speeds too.Jonttt wrote:I'm fitting the Schnitzer splitters this summer and they really should make a difference at exactly those speeds as their purpose is to provide more downforce to the front end at speeds where you would otherwise experience lift / light steering.
