Hi guys, I'm pretty new to the site I used to have an account a while back when I had my 240 but I forgot all the log in information. Anyway, back to the topic at hand. I have begun to track my 350 and have done two HPDE's (High Performance Driving Events) my last was at Road America, which was an awesome experience. Before going to RA I replaced all 4 rotors and went with Ferodo DS2500 pads and Motul RBF600 fluid. To start off the brakes were phenomenal but obviously as they started to heat up issues started to occur. I started to experience a severe shaking of the entire car under hard braking. I figured that maybe I exceeded the threshold of both the pads and rotors but upon just visually inspecting them they look fine. So my question is do you think that I may have fried the entire set up or are my control arm bushings to blame for the severe shaking. The car has 112K on it presently and none of the bushings have been replaced. I was thinking of going solid with SPL's line of bushings but didn't want to splurge on something if thats not the problem. Also, I know that the stock brakes are more than capable of handling what I'm doing with them with the right set-up but I'm definitely looking into Akebono's BBK. Any more feed back on what the problem may be would be great.
Thanks

Sorry it's a problem that brought you (back) to us but we're glad you're here!

It's been a busy week on my end or I'd have gotten you an answer, or at least a potential one, sooner. My troubleshooting process on car problems is always the same, get a list of all the potential suspects and start with the easiest and/or cheapest solution (it's always nice when those two intersect and better still when it's the right thing!) and then work my way down the list in cost and complexity.

When I hear someone talking about brake shudder my first thought is to pads and rotors, it sounds like that was your first thought too. You said you checked both but I'd actually go a step further and pull the rotors and have them resurfaced. Brake "warping" is one of those un-killable car myths, a lot like exhaust backpressure, but what may have happened is uneven rotor wear. Here are a couple of images from Stop Tech...






A driver can feel a 0.0004" deposit or TV (thickness variation) on a brake disc. That's not very much material.

You said you're using Ferodo DS2500 pads and you said you have new rotors as well but never said what they were. There is the potential for having an bad rotor but if you bought good ones I'd bet against it.

I've got the OEM Brembo calipers and I'm currently running DS2500' pads along with DBA Clubspec T3 rotors and steel lines filled with ATE SuperBlue (shhh...don't tell the DOT). Last month at the NICO meet at The Tail of the Dragon I certainly abused my pads trying to keep up with Gordon's beautiful 240Z (that packs a surprise under the hood - here's his build thread). About halfway through my pads were (as AZHitman said) "singin' to me". They never once faded or did anything except what they were built to do, but they did complain a little.

Ferodo is very specific about the bed-in procedure and if you don't follow it the pads can get a bit noisy. They have remained noisy under some pretty mundane everyday (for me) driving on the interstate but it' not gotten so bad that I feel the need to pull them, clean them and re-bed them and I have not experienced any vibration from hard braking...those DBA rotors are aces! So, given the "complications" of the Ferodo pads if you clean your stuff up re-bed them and the problem comes back up have the rotors checked for runout and then maybe start casting a suspicious eye towards the suspension.

Welcome (back) to NICO!

And post up some pics of the Z when you can!


Here's the complete StopTech article I pulled those images from, great read:

The "Warped" Brake Disc and Other Myths of the Braking System