Back wheels in front / front wheels in back

[Rosko]

OEM arrangement on my car is like this.

Front: 7.5" wheels / 225/50/17 tires
Rear: 8.0" wheels / 235/50/17 tires

I have replaced all four tires with 245/45/17.

I know this is not recommended (and possibly a dumb question), but would it be a big deal to switch the 8" wheels to the front and the 7.5" wheels to the back? I'm just trying to avoid paying $80 for removing and re-mounting, and plan to only use this arrangement for about three months - until these tires are autocrossed to death.

Why do this? The front tires are looking rough, and they are "feathering" aka "cupping" - a common problem on the 350Z. Basically, this means uneven treadwear on the inside and outside edges. It probably doesn't help that I keep 32 PSI in them during autocrosses. I can also hear a slight sound on the front right tire. It sorta sounds like it's flat-spotted, but it's not.

I realize that the best idea is to buy new tires now instead of waiting. If that's what I've got to do, then that's cool. I was just hoping to get more than 9 months out of these tires.

[PseudoRealityX]

find a new shop if they're charging you $80.

[w0rd]

You will probably have less grip in the back if you do that. Your rear wheels may be a different offset as well. Aren't you running Kumho MX's? If so, 32 psi is probably way too low for the fronts. I am going to run mine at about 42-3 psi in the front for concrete.

[Rosko]

Two tire places quoted around $80. I assumed that was what I should expect anywhere. Perhaps I'll look around some more. What SHOULD it cost?

Jeremy, yes, I've got Kumho MX. I don't want to lose rear grip, but I could probably make it up with pressure adjustments. I agree that 32 is low, but it seems like I've found the sweet spot. I find that this arrangement gives me plenty of notice when my car starts to slip. Then again maybe I'm missing out on potentially more grip. Perhaps on my next outing I'll use 32 on my early runs and 40 on my later runs.

Note: Not sure if you guys are aware but Vulcan Tire has some hellacious prices on Falken Azeni RT-615 right now. I don't think there is a sale, but the tires for my car are about $50 cheaper than they were the last time I checked. My 245's are $114! :jawdrop: I might just buy my next set of tires early.

[mofugga]

wider wheels up front may cause you to rub the fender or strut.

i get my tires mounted & balanced at mastro subaru for $40, $10/tire.

[Charles]

wider wheels up front may cause you to rub the fender or strut.

i get my tires mounted & balanced at mastro subaru for $40, $10/tire.


Good deal, I'll be taking my new daily driver wheel+tire package to them as soon as the UPS man shows up with them.....

[urn_uuid_owned]

Definitely, I second mofugga. Go to Mastro. Not costly, they know how to mount stiff wall tires quick. When I first moved here, I went to Wilseys...I can talk about that experience at the next autocross. No matter: I ended up going to Mastro; cool stuff.

[Mars_302]

why not just rotate them for DD to wear out the tire wear, then rotate for an auto-x?

[jaball77]

You will probably have less grip in the back if you do that.

I say do it. Challenge Jeremy for the title of DRIFT KING. :D

[Muddy]

super-dorifto!!! slide or die!!! :rofl:

[Rosko]

wider wheels up front may cause you to rub the fender or strut.

i get my tires mounted & balanced at mastro subaru for $40, $10/tire.

Thanks for the tip on Mastro Subaru. I went there today. I can't believe how cheap they are. Nobody can touch that price. My lowest quote was $79 and my highest was around $120.

The Subaru tech found that the jackasses who put my tires on 9 months ago at Tire Kingdom put the 7.5" rims on the right side and the 8" rims on the left side. Yes, I know. Brutal. He also found a possible source for the sound and vibration in my car - a very slightly bent wheel. Finally, he informed me that all four of my tires are shot, basically down to the wear bars, and ended up just moving the two best tires up front.

Anyway, that's a good service department. I recommend it. Thanks for the advice.

[Muddy]

All this time you have been handicapping yourself! :lol:

[FURIOUSS]

That's really ignorant for a shop to put both 8" rims on one side.
Maybe it helped you with right hand turns.
You were still pretty quick with the handicap. I'm scared now.

Thanks for the Mastro information. I would not have thought of them.

[mofugga]

no problem, glad you guys are happy with 'em!

[Rosko]

All this time you have been handicapping yourself! :lol:

You were still pretty quick with the handicap. I'm scared now.

LOL, Yeah right! I dont' think I'll gain the second or two I typically finish behind Muddy.

[Dunecune442]

People have gotten rid of that problem on 350zs by simply changing out the tire/rim combo to an aftermarket choice. Some have gone as far as changing the suspension setup. This will make sure it never happens again but ive heard very good things on the tire/rim alone.

find another shop, $80 is a ripoff.

[Rosko]

People have gotten rid of that problem on 350zs by simply changing out the tire/rim combo to an aftermarket choice. Some have gone as far as changing the suspension setup. This will make sure it never happens again but ive heard very good things on the tire/rim alone.

find another shop, $80 is a ripoff.

I do a lot of lurking at 350z forums. There is no known cure for tire feathering. Even Nissan service departments don't have the answer. If you have a 03 or 04, and they agree that your car feathers tires, they will easily replace your tires with the OEM size and brand for free. They will also align the car for free. However, the car will more often than not keep chewing up tires. To Nissan North America and Nissan dealers, this is the resolution. To many 03 and 04 owners it's a deep sore spot which has resulted in a big class action lawsuit.

There are a few folks, I've read, who have installed aftermarket hardware which allows you to adjust camber, and say that they have licked the problem. Confirmation / validation of this is sketchy. Note: You can't adjust front camber on a stock 350z.

The final solution to my problem: I bought 4 new wheels and tires which came from a "Track" model Z. I expect it to chew up these tires, but Nissan will replace them since they are OEM size. My only question: Can I still run in B Stock? The wheels ARE stock wheels from a Track model, but they are not the same dimensions, and they're 6 pounds lighter. It would seem ludicrous if I had to go to BSP because of this.

[jaball77]

Unfortunately if they're not the same width and offset (within 1/4"), they're not legal for stock class.

Seems pretty silly if you're running street tires, I know. But that's how the rules are written.

You could probably run BS with those wheels locally and not worry about protests. Or you could try to do a "package" conversion and upgrade your Z with all the special bits from the Track model. :)

[lunchbox]

OEM arrangement on my car is like this.

Front: 7.5" wheels / 225/50/17 tires
Rear: 8.0" wheels / 235/50/17 tires

I have replaced all four tires with 245/45/17.

I know this is not recommended (and possibly a dumb question), but would it be a big deal to switch the 8" wheels to the front and the 7.5" wheels to the back? I'm just trying to avoid paying $80 for removing and re-mounting, and plan to only use this arrangement for about three months - until these tires are autocrossed to death.

Why do this? The front tires are looking rough, and they are "feathering" aka "cupping" - a common problem on the 350Z. Basically, this means uneven treadwear on the inside and outside edges. It probably doesn't help that I keep 32 PSI in them during autocrosses. I can also hear a slight sound on the front right tire. It sorta sounds like it's flat-spotted, but it's not.

I realize that the best idea is to buy new tires now instead of waiting. If that's what I've got to do, then that's cool. I was just hoping to get more than 9 months out of these tires.


i once did a used car inspection on a 350z it needed tires and had a bad cup feather problem like you mentiond.. i decided to call nissan and speak with the foreman he explained to me that there is a service bulliten out with corrected alignment specs to cure this problem.... and he explained to me that everyone with a hunter alignment rack had the wrong specs .. this was about a year ago when i did this and dont remember exactly what the different specs were but id call and find out .. .. and for your original question is the offset of the wheels different? if not go for it .. the footprint of the tire should be really close to the same

[CanTheWhales]

Or you could try to do a "package" conversion and upgrade your Z with all the special bits from the Track model.

Okay, I might be stupid, but what are the differences...?

[Rosko]

Okay, I might be stupid, but what are the differences...?

Here are the differences between the 350z Track and my Z (Enthusiast).

Brembo brakes
Underbody diffuser
Vehicle Dynamic Control (stability control)
Lightweight wheels

I'm not prepared to spend thousands on Brembos and VDC - which I would turn off at an autocross anyway :) I'll just suck it up, and move over to BSP. I just think it's nutty since all models of the Z are in B Stock.

By the way, is BSP my only option or can I go into a different class? Nobody around here competes in BSP.

[w0rd]

BSP my only option or can I go into a different class? Nobody around here competes in BSP.
SM2?

[Muddy]

Just run BS. Nobody in their right mind would protest you out of the class at a local event. I suppose you could play in SM2 with me. I think I might actually attend some SCCA points events this year. :lol:

[Rosko]

I can't tell for sure, but I don't think Jim thinks I should be in BS. Jim's the guy with the orange Z. I've complained to him about having to leave BS a few times, and he doesn't say much. Maybe he's one of those people who sees rules in black and white, which is fine. Rules are rules after all. Perhaps I'll just ask him straight up instead of trying to be subtle.

The thought just crossed my mind that SM2 and BSP would kill my pax. It's sad that I care about that, huh? So Brian, I'll spare you the stress of competing with me in SM2 .... j/k.

[Muddy]

I can't tell for sure, but I don't think Jim thinks I should be in BS. Jim's the guy with the orange Z. I've complained to him about having to leave BS a few times, and he doesn't say much. Maybe he's one of those people who sees rules in black and white, which is fine. Rules are rules after all. Perhaps I'll just ask him straight up instead of trying to be subtle.

The thought just crossed my mind that SM2 and BSP would kill my pax. It's sad that I care about that, huh? So Brian, I'll spare you the stress of competing with me in SM2 .... j/k.
I saw that you replaced the tires on your stock wheels with some not-so-competitive tires. Why not mount race tires on the spare set? You won't do so bad in the pax, then. I won't be able to catch you until I get race tires, either. :cool:

[CanTheWhales]

Nobody around here competes in BSP.


Then I guess you'll win your class....