wheel grab
 

RX8 is my first sports car with wide tires (I have the 18 inch). Sometimes, I my steering wheel is grabbed either to the left or right. Is this normal? Driving a civic on the same roads, it doesn't happen but I guess that could be just different tires or something?

Its is the ruts in the road from the trucks. I think the DSC senses the different speed in the wheels and cause the pull. The great roads in Chicago around stop lights makes you spill your coffee.

Interesting. Since its just city driving I might try turning DSC off and seeing if it makes a difference. I didn't think of that.

Yep - it's normal. Wide tires, and the tight suspension of the 8 will cause the car to pull in response to ruts in the road.

It has nothing to do with DSC - it's a normal occurrence with wide, low profile tires, and is called "tramlining". Nothing to be done about it!

Regards,
Gordon

Thanks for clarifying that Gord96BRG. Happy driving.

Was going to ask the same question, I noticed it too, more so with the summer tires. Glad it's normal.

Yes, your not driving a minivan, do not remove both hands from the steering wheel at the same time, you are driving high performance sports car that provides road feedback. You need to be prepared for the feedback at all times.

Wait a minute RX8by... it's probably not the DSC.
 

I wouldn't fly off the handle and make an assumption like the DSC is causing this. Wide tires on a car can cause it to follow irregularities in the road surface, causing the car to veer left or right and the steering wheel to rotate.

The wider the tire, the greater the likelihood a section of the tread will "find" an irregularity and try to track along a different path than the car is headed on.

That's probably what's happening here. I notice it in my own Base 8 which has no DSC.

You can get 17 inch wheels with higher profile tires to mollify this problem a bit if you want. The increased spring rate of the higher profile tire will minimize tram-lining to a point. I drove all winter with this set up and I really didn't tram-line at all, but then again that was also with winter tires. Tram-lining is a result of the very low spring rates in low profile tires. Of course, less low profile tires also means worse handling. It's a toss up. Choose the one that you want, but I still have my 18 inch tires on for summer, and I love them.

Gotcha. Actually, I don't mind the tramlining too much. I was just wondering if it was normal or not since it was my first experience with this. I've usually got my hands on the wheel so its no biggie. Just different to what I was used to with the civic. The handling of this car makes up for all that and I wouldn't want to change that :)

Quick question for the techies out there. Does it have anything to do with the caster angle? Can this response be trimmed by changing the caster angle? I've read all about suspension, and know what caster angle is, but I don't know how that would affect the tramlining effect.

I thought Gordon invented a Sniglet until I saw this: http://www.tirerack.com/tires/tirete...tramlining.jsp

I noticed this big time when I when from my winter tires to my summer tires (that I never used since I bought the car in December). However, after one autocross I softened the edges of the summer tires up quite a bit and it's not tramlining much at all anymore.

Do you mean camber DJfreon ?

No, I meant caster. I know about camber, caster and toe. I know what they do, and how they change how a car drives. I was just wondering if the caster angle directly affects how much the car tramlines. On the RX-8 you can change the camber, caster and toe all very easily. If you get under the car you can see what I thought was the caster angle adjuster. The reason I thought about it is because I just read a review of the Chevy Corvette, comparing the C6 to the C5. They specifically said they took some caster angle out of the system to give the car "better on center feel." I thought that might relate to tramlining. Just a thought. I didn't know if anyone knew for sure.

I played around with some fairly aggressive alignment settings for several years on my Miata. I always liked to get as much caster as possible without interfering with my negative camber. With a ton of caster, the steering feels much different, but I didn't notice much difference in tramlining. Since I autocrossed though, I liked a bit of tow out on my fronts and a hair of toe in on my rears, which made the Miata ridiculously responsive, This was unfortunately at the cost of straight line stability- it wanted to follow the slightest groove or line in the road. I guess what I'm getting at is I believe that toe adjustment probably has the most to do with increasing or decreasing the car's desire to tramline, although the 8's rear multilink suspension is a bit different than the Miata's double-a-arm setup.