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dannyp84
dannyp84 Reader
3/1/22 7:15 p.m.

What are the factory tire sizes for your 350z? I run Z wheels on my is300, and though the rear wheels are 1/2" wider I use the same tire size on all 4. In my experience with the is300, a wider rear tire just promotes more understeer which the car already has a proclivity towards, so I like a square setup to try and make it feel a bit more balanced. Alignment also makes a difference in dialing out some of the understeer tendencies.

VolvoHeretic
VolvoHeretic Reader
3/2/22 12:15 a.m.

My Volvo 1800 has 265/50-15 tires on 10" wheels in front and 295/50-50 tires on 12" wheels in back, stagger diameter is 25.4" to 26.8". The front tires are the widest tires that will fit on the car without hitting the firewall at full lock (after some sledge hammering) with the wheels that have the correct backspacing. It under steers at low speeds (slow Autocross), but becomes neutral at interstate cloverleaf exit speeds (double the posted speed limit). I also use the same diameter sway bar at both ends which helps with the balance although I have never tried pushing it to the limit at high speeds. It looks great and I love it.

67LS1
67LS1 Reader
3/2/22 12:39 a.m.

Some cars look good with staggered wheel/tires and some don't. Since I never come close to the point my tires would loose grip, the staggered wheels on my car are purely because I like the look.

Keith Tanner
Keith Tanner MegaDork
3/2/22 12:41 a.m.

In reply to VolvoHeretic :

Same diameter sway bar at each end doesn't mean anything unless the geometry is also the same. But the balance is where you want it, so that's working.

I suspect you're really understeering at high steering angles, not low speeds. Might be worth looking into caster.

VolvoHeretic
VolvoHeretic Reader
3/2/22 1:15 a.m.

In reply to Keith Tanner :

I'm sure you are right about the sway bars, along with the unknown junk yard correct diameter but much larger diameter wire cut-down coil springs I found front and back, and the super low front ride height and front suspension moment center which results in way to much negative camber and... It rides like an empty dump truck and maybe that's why I have a bad back. :)

z31maniac
z31maniac MegaDork
3/2/22 9:02 a.m.
dannyp84 said:

What are the factory tire sizes for your 350z? I run Z wheels on my is300, and though the rear wheels are 1/2" wider I use the same tire size on all 4. In my experience with the is300, a wider rear tire just promotes more understeer which the car already has a proclivity towards, so I like a square setup to try and make it feel a bit more balanced. Alignment also makes a difference in dialing out some of the understeer tendencies.

I don't know if he mentioned year or trim. My 2006 350Z Touring was 225/45/18 Front, 245/45/18 rear. Which isn't a lot of tire when you consider power/weight. 

I think the Track trim was 245/40/18 front, 265/35/19 rear. 

ProDarwin
ProDarwin MegaDork
3/2/22 9:58 a.m.

Back in the day SCC had an article where they specifically addressed stagger on a 350Z  https://www.motortrend.com/how-to/0404scc-project-nissan-350z-part-2/

Oddly, they had same size tires but a 9" wheel up front and 9.5 rear.

 

Every fast 350 I have seen in the autox world uses a square setup.  Same with most other not-insanely-high-power RWD cars that come staggered from the factory.  M3, S2000, etc.

Bmsluite
Bmsluite New Reader
3/2/22 4:16 p.m.

In reply to dannyp84 :Factory sizes are a useless 225/45r18 front and 245/45r18 rear.  Naturally I have moved up to a 255/40r18 front and 275/40r18 rear.  I have tuned the car for the stagger it has now.  I am not sure I want to go in and retune it for a square setup.  Considerations are a

275/35 f & 275/40 R 

255/40 F & 265/40 R

265/40 F & 285/40 R (this may cause my front tire to rub the fender liner.  almost certainly will)

or

retain what I have now which is working well for what I do with the car.  In hindsight I should have picked up 19s as that would open up my tire choices hugely.  I did not do that nor do i want to throw a lower profile tire on the 18s because of ridiculous Chicago potholes.  I do have to drive the car home and I do drive it around the city because it is my toy.

GameboyRMH
GameboyRMH MegaDork
3/2/22 4:48 p.m.

Totally worth it to retune for a square setup, maybe 275/35s all-around?

Opti
Opti Dork
3/2/22 5:12 p.m.

I generally want the largest square setup I can fit. I also appreciate that sometimes cars are space limited at one axle so maybe a staggered setup works best. After driving a 4th gen camaro with sticky 315s at all corners, I can say it was not fun on the street, but a riot at the autox. I much prefer a 275/315 on a 4th gen mainly for the street.

Bmsluite
Bmsluite New Reader
3/3/22 6:08 p.m.

In reply to GameboyRMH :

That is most likely what I will do when I get a much stickier set of shoes that I can swap out at the track.  Need to make a little trailer for the wheels and stickies first.  I have stayed away from R comp as I ran some a long time ago (probably not comparable to how sticky they are now) and what happened was a lot of things broke on the car essentially immediately.  Like A LOT OF THINGS.  I am not so sure that the OEM parts on passenger cars are meant for those kinds of stresses to be placed in them.  I am not rich and like to have fun within my budget.

Bmsluite
Bmsluite New Reader
3/3/22 6:08 p.m.

In reply to Opti :

What ruined it on the street?  The numbness of the steering or the snapiness of the rear axle?

Opti
Opti Dork
3/3/22 8:23 p.m.

In reply to Bmsluite :

It tramlined like crazy, you couldn't enjoy the car on a backroad blast. Sticky 315s on the front axle are constantly trying to put you in the ditch or into oncoming traffic.

rslifkin
rslifkin UberDork
3/3/22 8:39 p.m.
Opti said:

In reply to Bmsluite :

It tramlined like crazy, you couldn't enjoy the car on a backroad blast. Sticky 315s on the front axle are constantly trying to put you in the ditch or into oncoming traffic.

That can definitely be a good reason for staggered tires on the street.  Run as much front tire as you can tolerate the steering behavior of, as much rear as you desire, then work on the suspension to get it balanced (and it may still need some driving style changes). 

GameboyRMH
GameboyRMH MegaDork
3/4/22 9:36 a.m.
Bmsluite said:

In reply to GameboyRMH :

That is most likely what I will do when I get a much stickier set of shoes that I can swap out at the track.  Need to make a little trailer for the wheels and stickies first.  I have stayed away from R comp as I ran some a long time ago (probably not comparable to how sticky they are now) and what happened was a lot of things broke on the car essentially immediately.  Like A LOT OF THINGS.  I am not so sure that the OEM parts on passenger cars are meant for those kinds of stresses to be placed in them.  I am not rich and like to have fun within my budget.

R-comps can be really hard on suspension bushings and the increased cornering Gs can be hard on your oiling and fuel systems, but keep in mind that there isn't a huge difference between the grip of R-comps and the stickier 200TW tires these days, so if you've been running those kinds of tires then there shouldn't be any big surprises in store.

Edit: The way to keep the suspension bushings alive is to replace them with polyurethane bushings BTW, my AE92 with sticky 200TWs and coilovers used to eat front LCA bushings like candy until I did this.

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