As you can see by my post count to the left here, I'm a newbie to posting here, and to a newbie to anything past taking my car to get its shceduled services as well, but anyway, my problem:

I have a '01 RS which had been running on the stock wheel/tire combo. I replaced the tires once, but got the same crappy Potenza RE-92's that were there in the first place. Anyway, I recently bought 17" Rota sub-zero's and 235/45 Potenza S-03's for some summer fun. I had them put on last week and the handling seems to me to be a bit off, (at least to my newbie mind).

Higher speed cornering seems better than before, but at lower speeds, especially while decellerating or on un-even pavement, I feel the car pull to one side or the other more than I think it should. And if I adjust the wheel slightly to one side or the other to say avoid something in the middle of the road, the car ends up wanting to go far more to that direction than I had intended, and requires a larger amount of counter-steer to get back to center, again more noticeable at lower speeds. I checked the pressure and put them at under the cold max pressure, but that didn't seem to help. What could some possible problems be?

I don't really know if it was some underlying problem with the alignment or something that was there before and I just didn't notice because of the less-than-great tires I had before.. Or if its a new problem due to the change.

Any insight would be a great help.

 

Yed,

The issue sounds to me like the standard "gone from 15s in a lowsy tire to 17s in the highest performance tire available" syndrome. It's quite common. Your new tires are among the most responsive available where your old tires are among the least. This combined with a 1" decrease in sidewall height amplifies the issue.

As long as the car tracks straight on a smooth road and feels the same right to left, the alignment should be okay - but you may wish to get it checked to be sure.

The new tires will cause the car to "tramline" - or follow the irregular contours in the road. This is natural. The tires will also cause the car to respond immediately to your smallest steering input. Since the car has soft suspension, the sway might make the car feel less control but I suspect you will get used to it and learn to contol it quickly to your advantage.

Overall, I'd recommend getting used to two hands on the wheel most of the time. It's small side effect to the huge improvements in traction and sportiness you'll receive. Also, your tire should be a 215 width and not 235. I'm assuming this was a typing mistake by you but if it's not, the tire is wider and taller than I'd recommend on the RS. This may have something to do with it - a bit more tire than your steering system likes to deal with.

 

Thanks for the input, guys. I guess I'll get used to the handling with time, but it appears another problem has come up for me.

The rear tires extend out to the side fender and rub (slightly, but noticeable) the top of it when the car goes over large changes in elevation in the road. Searching back thru this forum, the routine answer seems to be to get the fenders rolled up, but i have a few questions about that process if anyone is able to answer.

1) First off, cost estimate from the average body shop? Should a body shop more or less know how much to do? or is there some measurement that you would suggest? (seeing as i know nothing about the process)

2) There's a piece of plastic molding that goes around the inside of the side fender, which looks to be easily removeable. I assume its just to guard the paintjob along that surface of the car/look decent. What are the odds that the removal of this piece will give the tire enough room? I ask because it seems to me conceptually, the rolling of the fenders will remove this piece anyway.

3) If I have to roll the fenders, does it make sense to do the front ones too even though I'm not noticing any problem with anything except the rear?


Thanks in advance for any responses

 

A body shop usually charges around $200 for a four corner lip roll. You could try removing the fender liner - that would be my first step. You should try to determine if the front is okay before you decide not to roll them as well. You could take some sharp turns in an empty parking lot and listen closely.

 

While this may be begin to stray from exactly "tires", I'll post another reply here. I went to a body shop today to think about getting the fender's rolled. He said it would be $150 just to do the rears, which seemed a bit steep to me, but I'll shop around the area if I decide to go that route.

The guy at the body shop also mentioned a "spring tensioner" that I would put between the coils of the spring on the rear suspenion which would prevent it from compressing far enough to make the tire hit the fender. I don't know about the mechanics of it, but strictly logically speaking, that route doesn't really seem like its the best solution, given the fact that I'm running on the stock suspension and the springs expand and contract a signifigant amount, in addition to the idea that it seems it would put unneeded stress on the spring itself. Anyone have any input on that idea?