996 bump steer/tramlining ....
Discussion
i know this has been talked about before but looking for some advice. my current car (996 c4, 20k miles) is a joy to drive but the low speed handling in getting to be a bit worrysome. i seem to get a lot of bump steer on bad surfaces (and there are lots round my way) and it tramlines very badly as well. it has standard suspension. i mentioned the problem to opc at the last service and they claimed that all was fine. it kept getting worse so i took it down to charles ivy for a wheel aligment. things improved a bit but it's now getting worse again to the point where i'm concerned.
so a couple of questions....
1. is this probably caused by the tracking being out or could it be something else.
2. is there some reason why it keeps getting worse (we have a lot of speed bumps round us but i alwasy go v. slow over them).
3 should i go back to charles ivy again and give them another go or is there another independent in SW london that you guys could recommend?
i know it seems a minor to be worried about this because on a good surface (e.g. a track) the handling is great. it does not pull under braking at all. i just know that the car isn't as good as it was/could be.
any advice much appreciated...
si.
so a couple of questions....
1. is this probably caused by the tracking being out or could it be something else.
2. is there some reason why it keeps getting worse (we have a lot of speed bumps round us but i alwasy go v. slow over them).
3 should i go back to charles ivy again and give them another go or is there another independent in SW london that you guys could recommend?
i know it seems a minor to be worried about this because on a good surface (e.g. a track) the handling is great. it does not pull under braking at all. i just know that the car isn't as good as it was/could be.
any advice much appreciated...
si.
tyres are fairly new - they look fine though. that's another thing i was worried about (uneven tyre wear that is). if the inside edges look like they are wearing faster does that mean it's a tracking problem?
another thing. if your are on full lock (e.g. parking) there is a definate wobble as you move.
another thing. if your are on full lock (e.g. parking) there is a definate wobble as you move.
My 996 C2 behaves similarly. Previous owner, who was also a 3.2 owner, said it was nothing out of the ordinary. This is my first 911 so I'm no authority. Looking at the inside edges of my front tyres, they appear in reasonable condition.
Are you able to find another 911-owning PHer in your area who can offer an opinion?
Are you able to find another 911-owning PHer in your area who can offer an opinion?
DanH said:
Big fat tyres, crap road surface and communicative steering - thats how it is. Just relax and don't fight the wheel and it'll keep going straight.
Yep, all of the above and don't forget to keep a fairly relaxed hold of the wheel. The more tense you are around the arms and shoulders the more the car will respond in a nervous, twitchy way.
Sounds odd but it works.
I have just bought my first 996 C2, and similar experience with a slight wobbly feel through the steering wheel from time to time. Tyres are wearing even, and the OPC has gone out of their way to check it and I feel assured that it is normal. Had an exchange with a chap on another forum who said its natural on the C2's, just transfer of road surface.
I've heard that certain tyres are much much worse than others. My 930 was supposed to tramline badly but with Dunlops and Avons I didn't notice anything. Time will tell with the new Toyos...
I found a bit more info here
www.planetsoarer.com/offset/offset.htm
So you might want to do a quick survey of tyre make vs tramlining, Continental for instance don't seem that great.
I found a bit more info here
www.planetsoarer.com/offset/offset.htm
So you might want to do a quick survey of tyre make vs tramlining, Continental for instance don't seem that great.
It might simply be down to how sharp the edges of your tyres are.
A white line is like a mini kerb or rail, you have to climb it each time - sort of like trying to push a train off of the rails.
So we could therefore say that a car with tramlining problems has difficulty climbing the edge of the white line.
This difficulty would be down then to the hardness of the rubber at the edge, the steepness of the angle seen by the white line and by any play in the suspension and steering (like wheel-bogies on a train). Therefore I'd expect soft tyres with roundy edges to be much better than harder tyres with square edges.
Wear will naturally make the edge less round, possibly the weather and/or sun will make them harder.
A white line is like a mini kerb or rail, you have to climb it each time - sort of like trying to push a train off of the rails.
So we could therefore say that a car with tramlining problems has difficulty climbing the edge of the white line.
This difficulty would be down then to the hardness of the rubber at the edge, the steepness of the angle seen by the white line and by any play in the suspension and steering (like wheel-bogies on a train). Therefore I'd expect soft tyres with roundy edges to be much better than harder tyres with square edges.
Wear will naturally make the edge less round, possibly the weather and/or sun will make them harder.
BliarOut said:
17 or 18" wheels? The 18's look better, but I've read in previous discussions that they are more succeptible to tramlining.
they're 18" with new(ish) tyres (p zeros). i thought i might try experimenting with some different presure settings. handbook says 36F and 42R, i know my bike gets all weevy when the tyres go down a bit so i might try sticking another couple of pounds in the front (good/bad idea?) - i guess in winter the tyres will be that much colder and so should be able to take a might more puff in them?
si.
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