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UPDATE: Swapped my stock brakes and rotors on today. The vibes are a lot calmer but not gone. So safe to say, the 350Z rotors are not the culprit although the extra rotational mass contributes to the extra vigorous shaking. Going to check out my axles next....

Cliffs: 350Z rotors make my wheels shake...video at bottom...

About a month ago, my car inexplicably developed some vibrations when I was accelerating hard towards the redline.  At the beginning, the car would start to shake at around 4k RPM.  Enough to feel it but nothing too severe.  At steady speeds, no vibrations were noted at any speed.

In a matter of days, the shakes would start almost from idle, get pretty bad below 2k RPM, get a little better to about 3.5k and then worse after that.  I had to short shift all my gears to prevent my car from shaking apart.  Again, at steady speeds, no vibrations are present.  

I left for Florida for two weeks and when I came back I was ready to tackle the vibes.  But to my surprise, they got a lot better.  Car would not shake until past 4k and even after that, it wasn't too bad until almost redline.  

Now, my very first thought was that the engine mounts or the axles were going.  I checked the engine mounts and didn't find any torn or leaking ones.  After that, I checked the axles.  The axles didn't have any play in them and didn't oscillate in a crazy matter.  

Well, my next suspicion was that the suspension pieces must be getting tired with over 162k miles on the odo.  Checked play in the wheels, steering and control arms and could not find any excess play.  Save for the driver's steering rack, the suspension has zero slop.  Remarkable.  

I decided the only way to see where the vibes are coming from is to jack up the car and replicate the situation in a controllable manner.  After the wheel came off, I could see that the 350Z rotor wasn't quite centered when spinning.  Now, since the Nissan hub is 66.1mm and Honda is 64.1, there is a 2mm difference.  Everyone said that it shouldn't be an issue and that they wheel studs should center them.  Right?  Not in this case.  

Now, I've had my RL BBK installed since May 3rd 2012 and this is the first time I've had any issues with the rotors. They seemed to be fine with no vibrations for over 4 months.

Showing the problem...
2004 Honda Accord - YouTube (http://youtu.be/EYCNdHgY1Tk?hd=1)

Another angle I shot to confirm it's not the axles
2004 Honda Accord - YouTube (http://youtu.be/aKXFWqr69lU?hd=1)

At this point, I decided to throw the stock rotors back on just to prove to myself it is the 350Z rotors.  After reving the car, the shakes are gone.  I didn't record that but here is a video of the stock rotors spinning
Accord 6MT stock rotor - YouTube (http://youtu.be/hORzAurtj9c?hd=1)

Compare that to the 350Z rotors
350Z Rotor - YouTube (http://youtu.be/vYzMVA-Z8VI?hd=1)


Now the question is, what do I do? I managed to space the rotors while clamping them with the the help of a snow brush stuck between the seat and the brake pedal.  A 5/64" hex wrench sets the rotor equaly distant from the hub.  Then it's a matter of throwing on the wheel and praying that the rotors are centered.  After a quick drive, they prove that they are.  

I will be looking to find a local machine shop that can make a ring to take up the space between the hub and the rotor in the coming days.

Isn't there a way to use small hub centric rings similar to what I'm running on my evo wheels? There's gotta be 64.1 - 66.1 metal rings out there.

After my conversation with Milan, I'm pretty sure that if rings can't be bought, they can be machined.

I'm sure of it. Problem is, those are going to be some thin rings and probably expensive. I did a quick search and found the right size rings but they were all plastic.

I just bought some plastic 64.1-66.1 hub rings on eGay for $8.90 shipped.  I'll sand them down to the width of the rotor otherwise my Acura wheels won't be able to sit on the hub.  I believe that plastic should be okay since they work fine on wheels.  At worst I'm out $8.90

Let me see whatr I can find in 1mm thick material, at the end of the day even a strip run thru a rolling mill would work, machining the 1mm thick rings at only a coulple mm wide would be quite dificult to keep from falling apart in the machine.

1mm is 0.03937 inch. I can lay hands on 0.040 aluminum than would probably thin out to .039XX in the rolling mill to turn the cut off strips into rings.

mhh...after doing some conversions in Google calc, I was able to fit a 5/64" drill bit to center the rotor on the hub.  5/64 converts to 1.98438mm so the space between the hub and the hub on the rotor is larger than what it should be. 

Yeah, where did you get your rotors from? Tolerances especially around the studs have gotten really sloppy lately, I have even had to start shipping a extra spacer washer with the front kits where some rotors even have a slightly different offset.

Got them from Auto Zone but haven't had any issues for four months until now.   I got the ones with a 2-year warranty

I'd like to see opens are available with getting some rings.  Paul, let me know what you want for the rings when you get around to making some.  Milan, let me know how those plastic ones work out.

So this is why my car shakes....  For the life of me I couldn't figure out what it was after everything I looked at checked out okay.

Very interested in seeing what you come up with to solve this.   

I'll keep everyone updated.  Should be getting the rings on Friday but I won't have time to install them until next week most likely. 

Material is inbound. Milan how wide does the ring have to be?

5/64"

Not thickness, width of the ring.

I notice in the video that you only put 2 lugs on? Wouldn't that throw off the weight also?

I did the same after with all 5 lugs on with same result.  In the last video, you can see the problem, the rotor isn't centered. 

got ya... damn that really sucks. Hopefully those new rings help

Got the rings today and put them on.  One ring is not enough to make up the gap so I cut another one (since I have 4) and doubled it up.  This gave a nice snug fit.  I then had to cut off the excess otherwise the hub on the wheel wouldn't sit flush with the rotor.  Was feeling pretty confident because the rotor was pretty centered.  After a few pulls, the shaking is still present thought not as bad.  I have a suspicion that all the excess shaking may have thrown some things out of whack so even though it may not be the rotor contributing to the shaking anymore, it could be a result of that issue.  

Pretty bummed to say the least.   For some reason 3rd gear is the worst.  I can take it to about 5k RPM in 1st and 2nd before the shaking becomes very apparent but in 3rd it seems to come on before 4k RPM.  In 4th I'd be doing well in excess of the speed limit but I didn't notice as much shaking as in 3rd.  Not sure if that gear has anything to do with it but thought I'd mention it.

My next plan is to throw the stock rotors and calipers and see if the shaking is still present to eliminate the possibility of the rotors being the culprit.  I am also thinking of just returning the rotors for a new set since I have a 2-year warranty from Auto Zone.  

Milan, I have been using centric rotors from RockAuto with good results.

Hey milan, just had a thought, how about getting metal exhaust crush rings like are used in oe exhausts. The rotor should be chamfered on the back side and should self center as it is tightened down and crush forms the gasket ring.

These are the rings that I have. zero play

(http://i101.photobucket.com/albums/m77/thisaznboi88/IMG_12481.jpg)
(http://i101.photobucket.com/albums/m77/thisaznboi88/IMG_12491.jpg)
(http://i101.photobucket.com/albums/m77/thisaznboi88/IMG_1370.jpg)

Where did you get those rings Ken?  Care to share?

Yeah please do, I definitely need a pair.

He got the rings when he bought the BBK kit from what  I remember. 

^ sorry for the late reply. I got them with the BBK that I bought off DA a long time ago. I think fast brakes might have them. That is where the guy bought it. Or maybe it was custom made?

Lets start a list of who needs them. I just got done adapting pilot rotors to the rear of a civic and used a slice of 16ga exhaust tubing.

Let us know how much they would cost.  I'll start the list though.

1. timot_one - Tim

I'm not going to need them because the rotors are centered with the plastic ones I bought a while back.  The wobble is nearly gone from the rotor that I posted in the video but the shakes remain.  I will be putting the stock rotors and calipers on as soon as they get back from the sand blaster which was supposed to be a week ago  :mad:  I'll report on my findings. 

1. timot_one - Tim
2. ikethegreat

Since my car has been back on the road, it doesn't shake like it used to at highway speeds.  I replaced all my front lower control arm bushings and front wheel bearings though.  I had a wheel bearing that was really bad and the bushings had over 200k on them, so that may have had something to do with it.

Update on first page

What sort of ring do we need if we use these brakes? I bought Milan's calipers. I'll have to buy some rotors and probably pads soon

I have the same set up and only use hub centric rings on my wheels. My car rides just fine with no shaking. I had a feeling that Milan's problem was not the brakes and something else. The brake set up only amplified the shaking he was already getting.

No rings on your rotors?

Yeah, rings did absolutely nothing on my rotors.  And I included pads, hope you use them otherwise I could have kept them.