Steering feel with wider tires?

[TSY]

Originally Posted by wparsons

This! Scrub radius can make a big difference in feel.

I'm running 225/45 Z2's on 17x8 +45 (which is pretty close to the stock scrub radius) and the feel is just a tiny bit heavier most of the time, but it tramlines (follows grooves in the pavement) WAY more now. If you drive on roads that see a lot of heavy vehicles, you'll quickly find the grooves where they stick to. It's not annoying or an issue, but you will notice it.

I find different tires themselves tramline more than others. It may just be the Z2's like to tramline?

I'm leaning towards going with 225s too.

[jshadeck]

Yes. The manufacturers know what theyre doing. Thats why when they built a track car they went to 18x9.5 with 250 tires with stock HP

http://www.speedhunters.com/2013/02/...ned-eight-six/

[Vracer111]

Originally Posted by DarkSunrise

I immediately noticed more steering feel switching from the stock setup to 215 width max-performance summer tires on lighter 8" wheels in +45. Really happy about that. The only downside is the tires look a little stretched.

Whether the increase in steering feel comes from switching to sportier tires, lighter wheels, or slight stretch, I don't know, but I bet tires is the major contributor.

I have the stock Primacy HP's mounted on 17x7.5 Enkei Fujin's with +40mm offset and have noticed an improved steering response with a very slight increase in steering feel. Most noticeable though is the improved ride quality due to dropping ~3.5 lbs a corner... grip is also better than with the heavier and narrower stock wheels. Tire construction is probably the biggest contributor to steering/road feel, while mounting the tire to the widest recommended wheel width has more contribution to car responsiveness than road feel. Dropping unsprung weight mostly goes to improving the ride quality and secondarily handling responsiveness.

[RazBRZ]

I have 17x8 +35 Rota Grids with 245/40/17 Z2 Star Specs that shipped out today. We shall see how they feel in a few days

[MaDBaRMaN]

I have gone 20x9.5" all round on 245 rubber, I'm not feeling any significant loss in steering feel or functionality. If anything I find the wider rubber holds the road slightly better and results in less tail happy corners, this may also be due to the extra work the engine is doing to spin them :/

[DarkSunrise]

Originally Posted by Vracer111

Tire construction is probably the biggest contributor to steering/road feel, while mounting the tire to the widest recommended wheel width has more contribution to car responsiveness than road feel. Dropping unsprung weight mostly goes to improving the ride quality and secondarily handling responsiveness.

Yep that makes sense. The car feels so good right now in terms of steering feel and response that I'm hesitant to switch to 235/40/17 later. Might compromise and go with 225's.

[Vracer111]

Originally Posted by DarkSunrise

Yep that makes sense. The car feels so good right now in terms of steering feel and response that I'm hesitant to switch to 235/40/17 later. Might compromise and go with 225's.

I'm actually planning on going with smaller yet larger Max performance tires when it's time to replace the Primacy HP's...205/45-17 Kumho Ecsta LE Sports specifically. Smaller diameter but wider than stock tread width. Not to mention ~$80 a tire for an upgrade to the stock tires (a tiny handling upgrade in the dry but massive wet handling upgrade. Only trade is tire life is shorter than Michelins and not as good in really cold weather (fortunately I don't have to worry about really cold weather...), I can live with that for way less than half the price of Michelins...full set of high quality Max Performance tires for under $300 (they qualify for a $50 rebate...)!

[mrk1]

Width of the tire won't make to much of a difference, power steering is pretty strong. A difference can be felt if you run really drastic changes in offset like to fit a wide body. That's when you start messing with the scrub radius and have to push the tires rather then pivot.

[Mach V Dan]

Originally Posted by mrk1

Width of the tire won't make to much of a difference, power steering is pretty strong. A difference can be felt if you run really drastic changes in offset like to fit a wide body...

Wait...have you, or have you not experienced different-width tires ON THIS CAR?

--Dan
Mach V

[TSY]

Originally Posted by MaDBaRMaN

I have gone 20x9.5" all round on 245 rubber, I'm not feeling any significant loss in steering feel or functionality. If anything I find the wider rubber holds the road slightly better and results in less tail happy corners, this may also be due to the extra work the engine is doing to spin them :/

those wheels must be heavy! your sectional width must be smaller as well which will affect handling too.

[Khyron686]

Originally Posted by DarkSunrise

Yep that makes sense. The car feels so good right now in terms of steering feel and response that I'm hesitant to switch to 235/40/17 later. Might compromise and go with 225's.

225's increases the diameter too much IMO? 215 or 235(or 245) for stock diameter.

My dilema is stock 215/45-17 in Mich PSS, or get 235/40-17 in Falken FK-453 (lot less options in this size). I don't like the stretch look much, but value the razor steering feel more. Other threads have said I won't really be able to tell the different under 9/10 driving anyway.

[wparsons]

225/45 is 0.3" (7.62mm) taller than stock (25" vs 24.7"), and doesn't effect the speed readout (compared to GPS) at all.

235/40 is actually exactly the same difference in diameter (24.4"), just in the opposite direction. 245/40/17 is an exact match, but the differences between stock and either 225/45 or 235/40 are very small.

You'll feel the difference in feel at all speeds, but as with all cars feedback is more apparent closer to the limit because the tires will be moving around more.

[DarkSunrise]

Originally Posted by Khyron686

225's increases the diameter too much IMO? 215 or 235(or 245) for stock diameter.

My dilema is stock 215/45-17 in Mich PSS, or get 235/40-17 in Falken FK-453 (lot less options in this size). I don't like the stretch look much, but value the razor steering feel more. Other threads have said I won't really be able to tell the different under 9/10 driving anyway.

Yeah that was my reason for wanting to switch to 235/40/17 -- any shortening of the stock gearing is good IMO, but in all honesty, the difference in acceleration would probably be minimal as wparsons pointed out.

Then consider how the selection and price in 225/45/17 is much better, and that size starts to look really appealing. Also I haven't run into the rev limiter yet in autocrossing, but some people say slightly longer gearing helps you stay in 2nd on some courses. Hmm...

[MaDBaRMaN]

The 20's are actually 2kg lighter per wheel than the factory rims, gotta love the light weight hollow spoke GTR racing rims.