Steering feel with wider tires?

[f0rge]

I finally got my summers on, 18x8.5 in the front with a 225 tire.

First thing i noticed was the steering was heavier, but it still has lots of feel and still feels very accurate.

The better tires (PSS versus my winters) really made the car come alive.

[7thgear]

Originally Posted by MaDBaRMaN

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

what about the tires?

[jshadeck]

My bfgoodrich gforce tires in his size would weigh 25lbs, for an example

[avp1]

20" wheels are overkill. There is also a chance to break them on even tiny pothole. There is too little rubber to protect wheel from damage.

As to weight, ligtweight rims should balance an increase of larger tires weight to keep mass of assembled wheel close to or below stock.

[jshadeck]

Originally Posted by avp1

20" wheels are overkill. There is also a chance to break them on even tiny pothole. There is too little rubber to protect wheel from damage.

As to weight, ligtweight rims should balance an increase of larger tires weight to keep mass of assembled wheel close to or below stock.

Stock gtr wheels. Show me a pothole broken stock gtr wheel/tire please

Weight, as stated, is less than stock

[ShadowSeraph]

I just put some new ROTA T2R's on last night. They are 9.5 wide 38 offset and wrapped in 265/35/18 tires. My experience this morning is that the steering is a bit stiffer and very crisp with seemingly instantaneous response. Wide is good with this car.

[dsgerbc]

I went from OEM summers to 18x8 +50 and 225/40 Michelin PSS.
I don't really like it (probably keeping it for DD just for looks), the car is less playful at street-legal speeds. Just too much grip. Steering feedback is a bit stronger (grippier tire + extra 2mm of scrub radius), but somehow I have to turn the steering much more to get the car to rotate.

[wparsons]

Uhhh, where are people finding info that the 20" GTR wheels weigh less than our stock wheels??

Our wheels weigh 20.1 to 20.4 lbs each depending on source, from what I can find online the GTR wheels are 25.6lbs for fronts and 26.9lbs for rears.

Add to it that a more important factor is how far the weight is from the hub and you have a TON more rolling momentum over stock with the 20's. The barrels are the heaviest part of the wheel, so the further from the hub they are the more force they effectively exert on the brakes, or more force needed to get them spinning from the engine.

Go sit in an office chair and spin with your arms and legs stretched out then pull them in tight and see how the speed changes without changing the weight on the chair.

[TSY]

Thanks for all of your input guys. I decided to go with 17" 225/45-17 Michelin PSS on 17x8 +35 TSW Interlagos wheels:

http://www.ft86club.com/forums/showthread.php?t=35426

I need to play with the tire pressures a little but the steering response is quicker than stock tires but it's also just a tiny bit more numb. Again, may be due to tire pressures though or the slightly wider track.

I think it's a good compromise for a DD that sees some track and not super competitive AutoX duty.

[PowderfaceTr.]

[QUOTE= I definitely love the additional lateral grip. Bring on the cloverleafs[/QUOTE]

[altezza280t]

could anyone explain to me how wheel offset will affect steering feel all else being equal?

so say i go from stock to +35 will it reduce the excellent feed back and turn in the car has now?

[Gary in NJ]

Originally Posted by altezza280t

could anyone explain to me how wheel offset will affect steering feel all else being equal?

It effects the scrub radius. Now you have probably read that a dozen times, but what does it mean?

Picture the wheels as you go through a turn. The outside wheel is traveling at at different speed then the inside wheel, but due to steering geometry it is also at a slightly different radius. In fact, both wheels have a different turn radius then the center line of the vehicle.

The closer the wheels are together, the closer they are to the center line turning radius of the vehicle. So by moving the wheels further apart, the greater the delta (difference). A turn where the wheels are at full deflection has a much greater effect then a shallow turn.

Now the big question here is does going from a +48 wheel to a +35 wheel make a difference? The absolute answer is "yes, it does". Does it make a noticeable difference? Well that depends an the driver. An experienced driver that has a lot of track history with a +48 wheel will feel the difference going to a +35. Over the course of a day he'd become acquainted to the feel and probably not notice the difference unless he went back to a +48. Would it effect his lap times? Depends on the track. On a fast track where full luck turns aren't present, probably not.

On a daily driver, you may never feel the difference.

[altezza280t]

Originally Posted by Gary in NJ

It effects the scrub radius. Now you have probably read that a dozen times, but what does it mean?

Picture the wheels as you go through a turn. The outside wheel is traveling at at different speed then the inside wheel, but due to steering geometry it is also at a slightly different radius. In fact, both wheels have a different turn radius then the center line of the vehicle.

The closer the wheels are together, the closer they are to the center line turning radius of the vehicle. So by moving the wheels further apart, the greater the delta (difference). A turn where the wheels are at full deflection has a much greater effect then a shallow turn.

Now the big question here is does going from a +48 wheel to a +35 wheel make a difference? The absolute answer is "yes, it does". Does it make a noticeable difference? Well that depends an the driver. An experienced driver that has a lot of track history with a +48 wheel will feel the difference going to a +35. Over the course of a day he'd become acquainted to the feel and probably not notice the difference unless he went back to a +48. Would it effect his lap times? Depends on the track. On a fast track where full luck turns aren't present, probably not.

On a daily driver, you may never feel the difference.

Thanks for the detailed explanation. Now I know the "why" part.

Whats the actual "feeling" that will be different? turn in? feedback?

Thanks in advance!

[Gary in NJ]

By going to a +35 you are talking about increasing track from ~60 inches to ~61 inches. It really isn't a significant amount for a road driven daily driver because you're not turning at high speeds with a significant amount of steering input. Rim width, tire cross section, and certainly tire compound, can have an equal (or even greater) impact on steering feel.

Every change you make has an impact. If you are simply going to a +35 wheel, you'd be hard pressed to feel the difference. A +35 wheel, 8-inch rim and a 225 (or worse a 245) section width tire...well now the track is wider and so is the contact patch.

Will you feel it? Probably. Is it better or worse? Depends on what the driver likes. Will you care? That's entirely up to you.

If you can, try to drive a car that is setup like yours. Or, make the change and if it's not for you...sell it all and start over. A PIA, but no lesson worth learning is free and without risk.