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View Full Version : S14 shakes after z32 upgreade


Koukiii
08-26-2015, 09:20 AM
Hey guys,

Couple weeks ago I bought some 30mm z32 front brakes from a member on here and installed them on my car along with the provided used rotors/pads. Bled the brakes and they work fine but now my steering wheel shakes past 50ish-mph.

It is not terrible but its definitely noticeable. One of my favorite attributes of the car when bought completely stock was it's dead still steering wheel cruising at 80mph. First thought warped rotors but I'm pretty sure that causes brake pedal surging during decel which I get none of.

Maybe it could be the new rotors are a lot heavier than the dinky stockers and just cause vibration? Thoughts?

Thanks

fullthrottle
08-26-2015, 09:29 AM
Warped Rotors? Loose lower control arm bolt? Bad wheel bearing? Loose lug nuts? All things to check

BigKriss
08-26-2015, 10:02 AM
Rotor balance or run out of the fitted components. Cannot be warped rotors as that will only surface once brake pressure is applied.

DenkiMan!
08-26-2015, 10:04 AM
im having the same issue, pretty sure my drilled/slotted rotors got warped, bought them used after all. getting some brembo blanks soon

Koukiii
08-26-2015, 10:45 AM
Warped Rotors? Loose lower control arm bolt? Bad wheel bearing? Loose lug nuts? All things to check

Guess I will give those things a once over just never came to mind since I didn't touch anything other than bolting on caliper and rotor. Lugs are tight for sure.

Koukiii
08-26-2015, 10:46 AM
Rotor balance or run out of the fitted components. Cannot be warped rotors as that will only surface once brake pressure is applied.

Can you explain what "run out of the fitted components" means?

thanks

rawgarage
08-26-2015, 10:26 PM
Bet wheels are loose

BigKriss
08-26-2015, 10:46 PM
Can you explain what "run out of the fitted components" means?

thanks

A brake disc or rotor will locate centrally on the hub around the spigot collar. If this is not a pretty close fit (and by that I mean if its not absolutely clean the two parts do not slide over one another) , you may then have too much clearance and the disc or rotor can be mounted off set or off center. This will create an out of balance situation, very much like an out of balance wheel rim or tyre. A cast iron disc can cause severe vibration when not mounted centrally .

You may also have noticed that there are metal wire inserts around the circumference of the disc or rotors. This is a factory or manufacture balancing of the rotor or disc due to casting thickness variances.

Hope this helps.

Oh, and never try locating the disc or rotor using the wheel bolts or studs. The celarances are just way too large for any success here..:2f2f:

BigKriss
08-26-2015, 10:50 PM
Bet wheels are loose

Real smart reply , even more so coming from the world famous RAWgarage.....:-/

Koukiii
08-27-2015, 09:07 AM
A brake disc or rotor will locate centrally on the hub around the spigot collar. If this is not a pretty close fit (and by that I mean if its not absolutely clean the two parts do not slide over one another) , you may then have too much clearance and the disc or rotor can be mounted off set or off center. This will create an out of balance situation, very much like an out of balance wheel rim or tyre. A cast iron disc can cause severe vibration when not mounted centrally .

You may also have noticed that there are metal wire inserts around the circumference of the disc or rotors. This is a factory or manufacture balancing of the rotor or disc due to casting thickness variances.

Hope this helps.

Oh, and never try locating the disc or rotor using the wheel bolts or studs. The celarances are just way too large for any success here..:2f2f:

Thanks for the reply. Guess I will tear into it this weekend and check everything out.