Mods, please don't move this because this thread is strictly about the G35 sedans.

Some of you might know that Nissan has had major problems with feathering on the front tires of thousands of 03/04 350Zs. The orginial fix was to rotate the tires and pray for the best. When that didn't work they developed a different toe setting which seemed to help things. Okay, so I've got a G35 sedan with the same chassis as the 350Z, only 8" extended. About 1.5 years I installed 350Z springs to drop the G35 about 1". With the drop, I had no wear issues with the OEM Turanza EL42 rubber (215/55R17). Last September I installed a set of Avon MS550 215/55R17s and the design of the MS550's is 0.8" wider than that of the rather narrow EL42. While I was at Shore, I had them do an alignment. The initial settings were all within spec except front toe which was about -.11 degrees (toe out) on each side. The spec range is 0.00 to 0.08. They put the toe to 0.05. Fast forward to later November when I start noticing a slight roaring when slowing down from 30mph and also quite a bit more noise at highway speed. When I rotated the tires, I notice that the inner edges are feathered and somewhat cupped. I rotate the tires front to back and the noise disappears mostly. Then in March or so, the noise is back and the front tires are exhibiting the same issue. When touching the tire, there is an obvious temp difference between the inner edge and outer edge of the tire. The inside feels quite a bit warmer.

So my question for the gurus is what toe setting has Nissan dictated for the 350Z? Prior to getting my G35 aligned, it was a bit darty at speed, but nothing horrible at all. I don't know if the wear problem is because of the new toe, the 350Z springs (same spring rate as my G35 sport springs), or the additional width of the Avon tires, or a combination of two of more. My guess is it's mostly the toe. I'm debating about going back to about -0.05 toe and see what happens.

 

All three platforms have the same front toe settings.

Z, Coupe and Sedan.

0 or -1mm or -2mm.

Here's a thread you might want to read that talks about feathering on the Z.

http://www.my350z.com/forum/showthre...&highlight=toe

 

2 weeks after i dropped my sedan, i was able to get the sedan into factory specs (0.0 i believe) and the cross toe difference was 0. i'll take a closer look @ tire wear.

 

When I get home, I will look @ my alignment specs. I know I was having some feathering issues, but that was because I hadn't aligned the car after I put the 06 z suspension on. I didn't have any feather issues with the old setup of z springs/coupe springs rear on sedan sport shocks/struts. I will double check, but since I put the nismo suspension on and aligned the car, I haven't had any tire feathering issues. This has been approx 2k miles to include trip to z days and hard driving on the dragon.

 

I'm so confused now because I spoke with an ex-Nissan tech (currently works for Subaru) and he says that Nissan's bulletin was that the toe should be set to max toe-in. He remembered it being 0.10, but the G35 spec is 0.08. He said the other fix was that the Potenza rubber became a solid tread along the inside instead of multi-block. The reason I'm so confused is that my G never exhibited funky wear until I got it aligned and added the new tires. Even more confusing was that my G was severely toe-out (-.22 total) and I had absolutely no problems. The roar of the tires seems more pronounced especially when slowing down from 30 to 0.

 

Specs for front, aligned with 04-05 coupe 18" wheels

Right Camber: -1.2 (specified range -1.3/0.3)
Toe: 0.02 (specified range 0.00/0.08)

Left Camber -1.5
Toe: 0.05

Total toe: 0.07
Cross Camber: 0.3

The only thing out of spec is right front camber. I just checked the wheels again and I have no feathering issues with current suspension setup and alignment specs. Car is lowered approx 1.2-1.3".

I do get a roaring sound when I'm slowing down, but that only occurs while braking. If I let off the brakes the sound stops.

 

That's when it occurs on my car too.

 

I did some more research and my problem could also be compounded by the fact that I'm running directional tires (Avon M550s). By nature, it appears that directional tires can have a tendency to feather especially with multi-link designs like used on the FM chassis. Nissan had issues with Q45s and 300ZXs feathering with the OEM directional rubber and the fix became rotating the tires every 3000 to 3500 miles. It appears that the feathering experienced on the tires that were orginally mounted on the front for about 7K miles have been knocked down by the rear camber. I guess I'll rotate the tires, get the toe adjusted to full toe-in, and steer clear of directional tires on this car.