Slippin' and Slidin'
 

i caught some bad weather driving home from new orleans. it was raining pretty hard with a significant crosswind. my car started doing a wicked shimmy that made me slow down to about 60 mph. i'm used to feeling all the dips and groves and other road imperfections. the boxster S has pretty decent suspension, so i expect it to communicate those things. and, I10 in west louisiana and east texas has a pretty crappy road surface. but this was different. it really scared the heck out of me. i'm rolling OEM bridgestone tires with about 7K miles on them and pretty good tread left.

what suspension parts do i tighten, tweak, replace or add to make it stop?

I just responded to your thread on 6speed, but I will expand on it...

The south louisiana roads are trash. Rain fills the roads like rivers and the conditions sound less than favorable. A heavy LA rain with a strong crosswind is nothing to mess with, and if you got away with 60mph, you are going fast.

Unless you make your boxster 4wd or add 1000 lbs, you will not be able to do much to improve it's handling in those conditions.

1) I would recommend the "penny" or "quarter" test. Put one into the tread blocks. The penny head, if visible, means you have more than 2/32" tread. The Quarter, about 4/32" of tread. New tires start out with at least 8/32" of tread.

2) I would do what we used to do when i was growing up - drive you car to the level conditions allow. If they only allow for 60mph, go 60.. If they only allow for 40 then go 40. Trying to drive "80" in ALL weather conditions is just plain stupid. Slipin and sliding IS the feedback you want to realize you are exceeding the presented levels of grip.

3) In my limited driving in southern climes, I have found roads ill equipped to handle large volumes of rain. Poor soil near the roads, winds, questionable road surfaces (drainage and crowning, truck ruts etc) all contribute to less than perfect roads.

best thing to do is just drive slow

:cheers:

When I purchased my '02 S, I decided to drive home rather than pay the big shipping costs. So here I am in Dallas/FW heading north into Oklahoma in a big time rain storm...I was very pleasantly surprised at how well the car handled the adverse weather conditions. Also the last time I drove the car in those conditions!

Are you still experiencing a similar "wicked shimmy" - or maybe a less wicked shimmy on good, dry roads now? I ask because the Boxster I just purchased had a strange shimmy/shake/wobble/whatever that was most noticeable around 65 mph whenever I would lift off the throttle. Braking and cornering seemed to dampen it but in a straight line on freeways above about 55 it was a pretty serious wobble that seemed to come from the rear of the car. It turned out to be a worn balljoint on the drivers side rear lower control arm. I replaced the control arm and the problem is gone. Now I need to get a proper alignment. I imagined how really bad it would be if the weather and roads were treacherous.

You might consider jacking up the rear end, grabbing the rear tires with a hand on each side of the tire and give them a good twist (and of course make sure your car is secure on the jack or jackstands) and if there is any motion, wiggle, or play you might have a worn ball joint. Have someone watch the wheel while you try to move it - they may be able to notice the movement easier than you would be while you're trying to move it. I was able to see the excessive play in the ball joint by looking at it under the car while someone else was wiggling the tire.

You didn't say if the wiggle seemed to come from the rear of the car - so it could be an issue with your front end. I would try the same tests to the front end as well if it's not obvious where the shimmy/shake/wiggle is coming from.

I should have taken pictures and posted a thread on this replacement procedure on the DIY section but I forgot. If you suspect something like this let me know and I can go into more detail if necessary.

Then again as mentioned in other posts it could just be a case of adjusting driving style to bad roads and bad weather.

Ken

Our cars are amazing in the rain! But ya gotta have good tires. Several of us did a few runs on The Tail of the Dragon in complete rain. I was shocked how well our cars did.

hey folks, thanks for your replies. :)

the rear tires passed the penny test before i left for LA.

i was definitely driving for the conditions, sometimes going less than 50. it was just frustrating having SUVs and pickups blow by me doing 70 or better. i live in texas, i should be used to knuckleheads going too fast. :o

i always try to avoid taking my car out in the rain. however, it is a daily driver. so, sometimes i can't avoid it. (it is garaged on both ends of the commute though.) the few times i've driven in the rain here at home, i haven't had any trouble maintaining freeway speeds and feeling safe. nostalgia for LA must have made me forget how bad the roads and weather can be.

i think i'll check the ball joints just to be safe. but, the shimmy only happened in those adverse conditions.