'03 Touring, pretty much stock... just pad and rotor upgrades, no HP mods, summer tires (Florida).

I've noticed that after each track day I seem to be getting more road noise, almost as if I'm running 4X4 knobby tires. The drone-like sound get worst as speed increases or in corners. Applying the brakes seems to quiet things down. Thus I assume its the hubs. Especially since this is listed as one of the standard parts that gets used quickly on tracked vehicles. Am I on point here?



If so what replacements should I get? Premium or Standard appear to be my choices from forum vendors.

 

Timken or OEM.

 

I would be surprised if they all went at once.

You should be able to make the suspect hub louder by turning away from the side that has the bad wheel bearings. (Increasing load on the bad hub, and the noise it's making.)

 

That's what I'm thinking too because the sound doesn't change much turning right or left. The noise is annoying going straight ahead, but gets worst turning, almost like you rolling on the sidewall of a flat tire.

I'm just going to switch out all 4 because I have to do some brake work as well.
(rant)Useless, undersized OEM brakes on the track (/rant)

 

Try jacking the car up and checking different items for play. There shouldn't really be any play so that could narrow it down.

 

Have you checked the tires themselves. Bad feathering can make a pretty noisy tire as well.

 

Tires look pretty evenly worn but give them the once over.

I will also jack the car up, spin them and check for play.

I started noticing the problem about 2 track events ago and its got MUCH worst after this last event.

 

This is actually my thought, my 05 the tires looked good but they would roar pretty well.

Bearings and hit n miss. My 03 has 157k on it, plenty of track miles and still has the original front bearings. The rear bearings have beed replaced once now. Others go thru a set of front bearings a season.

 

Just got my Z and yes the brakes are small. They heat up super quick, after a spirited driving session I get out of the car and smell brakes for days. Do you think upgrading to slotted rotors and ceramic(maybe hawk pads if they make them for our Zs) would help?

Any recomendations on drilled/and or slotted rotors that will fit a stock 06 Z?

 

Your '06 brakes are bigger then my '03... in fact they are considered an upgrade! Forget drilled and slotted as that just REMOVES material, you need to ADD material for better heat distribution. Thus the reason for BBK. The downside of BBK is weight. And because racecar heavy = slow.

Also "spirited driving" is way different then track days, just pads should be good enough for you. But I'm still be a track newbie, thru I'm horrible on brakes and going thru pads like a fool

 

exactly right, plus drilled and slotted rotors add stress points that crack with heavy use.

 

I rechecked the tires today while getting gas (still haven't pulled them off yet) and while they LOOK fine, if you feel along the outside shoulder they might be feathered Which shoulder shows this problem worst: inside or outside?

And if it is feathering what is the fix? I've read that feathering is another early Z "feature" that was corrected later somehow (suspension). Is this correct? What needs to be checked? Standard alignment? Or should I tell them some specific?

 

With negative camber it will be the insides.

 

If you have a stock alignment you will tear up the outsides of the tires pretty quick. Look into camber arms for front and rear, there is not much adjustment with the stock components.

 

So with camber arms what alignments should I run?

Just as a follow up... its NOT the hubs!

I jacked the car up and they is no play, they spin in near silence (just tiny disc brake drag). So I took it to the shop were I get tires for all my vehicles and had the alignment fixed to the TSB specs for tire feathering (2mm / 2 degree toe in, zero variation). I'm going to rotate the tires side-to-side (swap driver and passenger sides) in attempt to even things out and get more life out of the tires.

 

im at 82k and a lot of events over the last 4 years tracking my 350z. Only hub Ive changed was right front. Other 3 have not had issue, and I check before each event.

 

Follow up to the follow up... it WAS the hubs

Maybe this was a case of which came first: the chicken or the egg ?!?
1) the alignment caused the tires to become worn, which vibrated the hubs to death
2) the hubs were bad, which worn the tires out

Got the car aligned, put on new front tires and it was still shaking and making terrible sounds. The hubs however were solid: no play at all, spun pretty free and quite. However the passenger side did have a slight bearing grinding type sound but you could only detect it with everything off (wheels & brake rotors). With the rotors on the slight brake drag was enough to mask the sound. Once I pulled everything off the hub you could feel things weren't right and hear a slightly odd sound. It wasn't bad... until you drove the car then the vibration and sound returned.

Oh well its fixed... for now, I hope

 

Glad to here you found the probelm and were able to fix it.