Spike100

I’ve been an advocate for running 245’s all around. I’m running Goodyear Eagle F1 GS-D3 (245/40-18” F and 245/45-18” R).

I like this setup since it turns-in quickly. I also thought it handles very well with neutral-steering,

But, lately I’m not so sure. I’ve experienced a few driving situations that definitely show this setup as over-steer rather than neutral-steer.

If you go into a turn and pull hard on the steering wheel while applying power before reaching the apex, you can easily lose the rear with this setup. And, that’s on a dry and smooth roadway.

I’m posting this because I’ve mentioned in the past that this setup will provide neutral-steer. In fact it easily goes to over-steer (and that is tricky handling).

If you go with 245’s all around, be careful. You are probably safer going with wider rear tires if you mount 245’s on the front.

--Spike

WheelDude.com

iTrader: (58)

A non staggered tire setup will handle fairly neutral but at the "limit" the car will definitely have a tendency to oversteer. For track use or aggressive street driving (with proper experience) a non staggered setup is very fun to drive with. Braking is especially fun with non staggered setups as you can really control the car when coming hard in to a turn and get it to rotate easy.

I typically recommend staggered setups for daily driven cars unless you have a lot of driving experience and are familiar with the characteristics of non staggered setups. A staggered setup will definitely help at times you go a little too hot in to a corner as the car will start to push a correct fairly easy.

-Dan

Spike100

^^ Dan,

Thanks for the reply and adding more information. The sponsors here provide the best advice about wheels and tires for the Z.

You are correct. It’s really the driver that makes a setup work correctly. An experienced driver will have no problem with this non-staggered setup.

Actually, I like the 245’s front and rear for the reasons you mention. It’s fun driving this setup.

After driving on this for awhile, I was a little surprised at how quickly this setup went to over-steer; and that’s the reason for my thread. I didn’t want someone to adopt this, and then have problems.

--Spike

donkinuts

iTrader: (3)

I didn't realize that having the same widths in front and rear would induce oversteer. I would have thought it would be the opposite.

Anyhow, thanks for the advice as I was thinking of going with non-staggered setup. I guess I'll stick with the way it came from the factory.

Spork

iTrader: (6)

Thanks for sharing!

HyperSprite

iTrader: (6)

Spike,
I got to wonder what swaybar settings you are running.

I've been running 275s all the way around for the same reason, neutral handling, and when I first did it I was running stock swaybars and the car handled wonderfully.

I then upgraded to hotchkiss swaybars and set them up as recommended. I believe it was middle-F/middle-R.
The next time I was at the autox the car was downright scary. It was tail happy but in a upset sort of way, not the smooth slip I am used to under throttle.

Realizing that the stock bars handled well with the square setup, I compared the hotchkiss to the stock bars and with the front bar set at medium, that is 80% stiffer than stock (middle hole on the old bars, second from the end on the newer ones) and medium (middle hole on the back ) was 140% stiffer than stock (I think that is the number it has been years) but the last hole was 80% stiffer. I moved the end links to the last hole on the back bars and the next time I was at the autox, the car performed as expected. It was also smooth as silk at Thunder Hill with no unexpected stepping out.

Just a thought,

terrasmak

iTrader: (8)

What suspension do you run ?

Also with what you said , even our understeering pig of a car in stock for can turn into oversteer almost instantly. Driver input, steering, brakes and or throttle , and road conditions can effect that.

But then again, the car shoudl never really be pushed to the point it becomed damgerious on public roads.

scotts300

iTrader: (46)

I'm also curious if you have tried softening the rear sway bar...

Clam

iTrader: (6)

I just switched to 275's all around and also find a square setup to be a little tail happy compared to the stock staggered setup.

The first run I did in autox I was all over the place with my tail swinging out during each turn. Took me about 2 more runs to get used to the setup, and I was able to shave off 4 seconds from my first run .

Like everybody says, the car is going to be neutral so it is going to be more sensitive to what you do with the steering, brakes, and gas.

Even when I drive on the streets, I had a few instances where the tail steps out on me when turning due to me trailing off the throttle.

Spike100

HyperSprite, terrasmak, and scotts300,

When three of the most knowledgeable guys here ask nearly the same question and offer similar comments, you can be sure I listen.

Answering your question… I have a 2003 Performance model (with 40K miles), and I’m running the stock suspension.

I didn’t care much for the stock tire setup (225 F and 245 R) on my Performance model since it has too much under-steer. That’s why I went with 245’s all around (245/40-18 F and 245/45-18” R).

I really like the fast turn-in with 245’s on the front, and the most-of-the-time neutral-steering with 245’s all around. I just notice that the 245’s all around can go to over-steer if you pull hard on the steering wheel while applying power to quickly (before the apex). I’m not talking about any high-speed turn here that should only be done on the track, but describing a street maneuver that is well within legal limits.

Since I’m at 40K, it will be fun to do a suspension upgrade. I’ll start searching on the appropriate sub-forum here (Brakes & Suspension at my350Z.com) to find what I need to improve my car’s handling.

Thanks guys for help which I always appreciate from our members. This Forum really improves the experience of owning and driving a Z.

--Spike

Spike100

Hi Clam, …Thanks for posting a reply. Reading your good response makes me think more about this.

You would think mounting a square-width-tire setup results in neutral steer. But, as you point out, neutral-steer can quickly go to over-steer, depending upon several variables. For one thing, the Z’s weight distribution is slightly heavier in the front, so this setup (all-square widths) will have a very slight tendency towards over-steer.

I’ve been searching the Brakes & Suspension sub-forum to gain more information. So far, I haven’t been able to make any reliable determination about changing the anti-sway bars and/or springs/shocks to improve handling with an all-square setup.

For now, I’m being more vigilant when entering and exiting a turn (when I brake, apply power, etc.). Better driving-methods seem to solve the problem.

For sure, I really like driving an all-square-width setup. I’ll never go back to 225’s on the front, but might consider a 245 front with a slightly wider rear tire.

--Spike

Tac-M

iTrader: (17)

245 on all 4 ? muahahah !!!!!

Spike100

^^ WT_?

Where did you come from?

I don’t think that 615/225-10” tires in your pictured-example fit the Z without some serious fender rolling.

But thanks for your contribution to the thread (I think?).

--Spike

JETPILOT

iTrader: (51)

People talk about the handling of their cars as if A) they were knowledgeable about suspension setups, and B) as if a car is a static object.

Every chassis will exhibit many behaviors depending on the dynamic state of the vehicle. There isn't a single word to describe the way a car will handle under all conditions.

I find my Z likes a larger rear tire and seems very neautral during a throttle on steady state turns. I run a 275F tire and a 305 R tire and I have been very happy with the way my car handles in most situations.

Tac-M

iTrader: (17)

no worries man, i am just slightly confused myself. most of people here run 245f/275r and track guys go with 275 on all 4, 275/305.... and so on

i run 265/295


so i just think that 245 is way to small for a z.

WhiskeyHotel

iTrader: (5)

The fellas I know around here that track their Z's run 275 square. My driving skills are marginal so I prefer 245/275 to make sure I plough off the road frontwards if I do something stupid.

This article was fairly helpful as far as handling. (A lot of the tire rim/spacer stuff I could have done without, but...)

http://www.modified.com/projectcars/...t_2/index.html

M1r4cL3

iTrader: (8)

I ran a 245/275 combo for about a year thru autoX and a couple HPDE.

I've since switched to a 265/265 setup and I'm amazed how much better the car rotates. Understeer is all but eliminated as the front end will hang on allowing the rear to pivot around the axis. The car is so much more enjoyable to drive now that I can rotate the rear w/ the throttle thru tight autoX hairpins and sweepers. That was impossible with the 245/275 setup as the front end would push outward when the throttle was applied. I also have noticably higher corner entry speeds as I can rely on the extra grip in the front to pull me thru.

terrasmak

iTrader: (8)

You can also throw driving style into the mix, and to also emphasize what you said. NO TWO CARS HANDLE THE SAME . You could set up two cars identical and they will feel different.

Spike100

I’m happy to hear someone else say this (especially from such a good source). I’ve mentioned this a couple times here, and always “take a beating” for this comment.

For one thing, tire wear makes a huge difference in a car’s handling, and that can happen very fast with performance tires. For example: The average mileage/lifespan of a NASCAR tire is 150 miles.

Compare this statistic to drivers running summer-performance tires a few thousand miles. It’s no wonder the opinions of tire owners are all over the place. The best time for a performance tire happens after you burn-off the grease and during the next few hundred miles when it drives as it is meant to in its optimum state.

Of course we don’t drive on the street like we do on the track (you expect much longer wear and consistent handling when driving a tire only on the street), but street driving also takes its toll with irregular surfaces, road hazards, and other bad things (that results in irregular wear).

In fact no two drivers running on the street (with all of its variables) can expect the same result from the same tire (handling or wear).

--Spike

Goku350z2007

iTrader: (6)

Stupid question for you guys, i need to replace my front rims (one rim is bent) if i buy two rear OEM rims and have a square set will i have any problems if i do this?
thanks