koyv90

I have 18x8.5 +25 and 18x9 +22 on my car I was wondering if I can run square wheels and if I could negate the under-steer that staggered wheels supposedly produce? Or is it not that big of a difference and I can run staggered tires as well?

Or is it best to fine tune the balance using the suspension?

Sorry new to 350z suspension/creating neutral balance.

Spike100

Handling is a complicated issue. Weight distribution, suspension, wheelbase, tires, and other features affect the way a car handles. Engineers and mechanics spend endless hours on countless tests to determine and alter a vehicles handling. Solutions are often derived from drivers’ feedback.

A small amount of under-steer isn’t necessarily a bad thing. Under-steer provides a measure of safety by allowing some plowing when a driver enters a turn with too much speed or doesn’t exit with the correct amount of power.

Over-steer is something drivers want to avoid since this can cause a spinout and loss of control. It's very disconcerting when the backend releases and you are spinning.

Neutral handling is a term some use to describe the midpoint between under-steer and over-steer. The easiest way to achieve this is mount the same width wheels front and rear along with the same width tires front and rear. Actually you want the same tread width which isn’t necessarily the same tire width when comparing wheels widths and tire diameters. It can get complicated. And, neutral can go quickly to over-steer as the rear tires wear.

I’m sure the Moderators here can explain this better. These guys actually race the car and know a lot more about this than I do.

dkmura

iTrader: (64)

Using suspension components like swaybars and springs to adjust the overall balance of the car is much more effective than worrying about wheel sizes. This balance is also affected by suspension settings (camber, caster and toe) and shock settings. Keep in mind what you consider neutral will change under braking or adverse weather conditions.

Spike100

^^ Wow! That is so well and concisely stated I don’t know if anyone can improve upon the general message you present.

With that said, I think the OP will ask for more info.

--Spike

koyv90

So far that is my wheel setup with 270/40/18 in rear and 245/40/18 my fronts are balding and rears will begoing bad soon as well i was thinking 245/40/18 in front but don't know about rear.

Also will be upgrading to fortune auto 500 coils soon.

Emski

That huge stagger contributes to understeer. Get a square setup and tune your suspension from there.

terrasmak

iTrader: (8)

In a perfect world neutral balance should start with equal tire width. It is a great starting point, from there you have other stuff to factor in ie weight distro, power, braking, drag.

The Z being nose heavy, mid power and a semi porky car likes some tire width. My car runs a 285 square setup, dam near perfect for my needs. It kills the MPG for street driving, a bit rough on the brakes but it works well. Im actually going to try 275 square next. A Z the never see's the track, sure as hell does not need this kind of combo but a 245 to 265 combo could be great.

Using suspension to tune it. High HP cars really need bigger tires in the rear, sway bars, spring rates , camber etc etc can all be used to get the balance back. You have to make it fight the tires to do so, this is who I don't like the idea unless it is needed. Every tweek does something, some good some bad. Bigger rear, and stiffer springs, changes the weight transfer, changes the traction , if you keep softer springs you would have to change the sway bar settings , not your trying to get the perfect balance of on throttle grip vs neutral at neutral throttle. It is a huge game, a huge game of balance, trying to figure out the perfect balance for your needs.

To the OP, what are your needs? Canyon, track, autocross, drifting?

koyv90

daily driving mostly with a side of drifting and canyon driving. Car is running a turbo and will be re tuned to 450 hp.

terrasmak

iTrader: (8)

I would probably stagger with that power. I would also want a wider set of wheels

koyv90

wider then 40 on each wheel?

Thank you all for the help.

koyv90

bump

Emski

Go read the fat tire thread.

terrasmak

iTrader: (8)

40 is not width, it is aspect ratio.

Example 265/40-18 , 265 is width , 40% of width is tire height and 18 is wheel size.

koyv90

okay so you were saying 245 on both is good square? or i should stick with the 245f/270r ?

Emski

If you are running a turbo, 245 out back is not going to cut it. 255f/275r is a common street performance setup. 275f/r would be more neutral and popular for track/autox, but won't be a good fit for your 8.5" front wheels.

koyv90

well i have 245/270 but how much bigger is 255/275? feel like i dont have much room to get that bigger and still be able to turn/raise car.

Spike100

You won’t feel much difference, if any.