I am thinking about some new wheels. Sizes are:

19 x 10 et 20 front and 19 x 11 et 23 rear.

Has anyone who's fitted a "10 front had any negative effect on handling?

Any bump steer at high speeds?

I was thinking of using 255/35 and 285/35

 

No one has ever put 10.0 inch wheels on the front of a 350Z. Call yourself a trailblazer. A pioneer.

 

I have run 10 and 10.5" front wheels on my Z without noticing any drawback. I'm not sure I understand the mechanics (or geometry?) that make a 10" wheel the break point as-compared to a not-much-smaller 9.5" or 9" front wheel? I don't, however, see a reason for a 10" wheel if only using a 255mm tire. Same goes for 285 on 11" rear, but I'm listening.

 

You shouldn't any issues (rubbing etc.). I'm running a simular front 19x10 offset 15 and 255/35/19 tires with no issues. As for handling, I think my results are a little different because I'm running a squared setup. My setup feels a little more balanced (netural) but again my tires are rotating at the same speed. My rear is 19x10 offset -5 with a 255/35/19 tire also. Your setup should handle simular to stock. Your overall circumference is pretty close to stock.

 

Purely cause I already have those on my current wheels. I am happy with the way it handles at present. Going to coilovers and a drop and have seen the wheels I want. If I don't like the way it feels I'll change to some wider rubber once I've worn out the ones I've got.

I have heard that beyond 9.5 on the front can cause bump steer at high speeds.

Any suggestion on tyre sizes if I change them?

 

I have 19x10's F/R with a Hotchkis suspension with no problems at all.
255/35-19
295/30-19

 

the tire size would determine the handling right? I have 17x10 all around 255 front and 275 rear and the car handles like a beast. sticky around corners and responsive on the highway

 

“Bump-steer” is a concept described with a somewhat vague definition. It has more to do with wide front tires than wide wheels (although wide tires are often combined with wide wheels). Off-roaders complain most about this because they often run wide tires with the same size (width) front and rear.

The environment that promotes “bump-steer” is expressways that have a high volume of truck travel (heavy 18 wheelers). The heavy trucks have tandem wheels that result in depressions in the roadway with a rib that develops between the tandem wheels.

If your car has 255mm or less wide front tires, you ride inside the depressions and rarely notice the ribs and you do not need to worry. But, if your car has a great suspension combined with very wide front tires, you may bump up against (or constantly ride across and up-and-over) the rib left by the tandem tire depressions caused by heavy 18 wheel tractor/trailer trucks. That can require a continual need to correct direction, and it is very annoying for some drivers (albeit some people never notice this).

Wide front tires are never a problem on smooth roadways such as the track or well maintained streets.

A well balanced staggered setup (e.g., 245/275 or 255/285) minimizes bump steer since the wider rears have enough push to keep the fronts going straight, and the more narrow fronts respond less to irregularities on the roadway.

--Spike

 

Thanks for the all replies, very informative and more or less confirmed what I was thinking.