kam1996

I was driving to work and this "person" in a new Z4 was riding my tail. I moved over (just wasn't in the mood to teach him a lesson for tailgating) and he comes right next to me and started driving the same speed i was, I look over and he has this childish grin on his face. Usually I make it a point to not mess with the "squids" (Squid is what me and my fellow motorcycle road racers call "a street racer", endangering him/herself and everyone around instead of being on a closed course race track)..
anyway, we both stepped on it and around 45MPH i had a couple of cars on him..by 85-90 I was a few cars ahead Z4s are pretty underpowered, unless its an M edition, so it wasn't a fair fight, I stepped on my brakes and the whole steering wheel started shaking.
Now I havnt had to really "USE" the barkes so far, so I didnt realize how weak the brakes were..I bought the car from CARMAX and personally had the car lifted to check brakes (pads, rotors) and they looked 90%. I also had the rotors checked for wear and they were in good shape..Why then did my brakes feel like they were going to explode...I understanfd that I was going pretty fast and wanted to stop the car in a rush..but that is the point..Brakes shouldn't feel good only when you use them lightly...
So , what do you guys think..Do i need better pads..newer rotors..or get the present set up checked again...
.
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Once the brakes had cooled down I tested them again and after just one hard stop the shaking was back...

RON430

I had a chance to do a fair amount of lapping at Laguna Seca in my GS recently and was able to compare the GS to both an M5 and an E55. I have stock brakes and I can pretty much assure you, you have a problem. The stock GS brakes may or may not lack some feel but they are very good. It impressed a few other folks as well. Without knowing more, the steering wheel shaking with the brake application is most likely warped rotors. Doesn't really matter how much pad is left.

As for other brake system improvements, there are some that will no doubt increase ultimate stopping power, but if your driving style suits them, the stock rotors and pads are surprisingly good.

rominl

iTrader: (4)

you have warpped rotors that's all

Indio

iTrader: (1)

Once you have your rotors resurfaced or replaced make sure your wheels stay torqued at 75 foot lbs, whenever your wheels are removed make sure the tech understands this because if he uses an impact gun you will continue to have this problem. You also didn't say what size wheels you are running, if you have upsized wheels your brakes will not work as well due to more unsprung weight.

bitkahuna

iTrader: (20)

Wheel shake on heavy braking doesn't automatically mean the rotors are WARPED. It often means there's uneven deposits of brake pad material embedded in the rotors so that when hard braking occurs it's like the pad's going over a mountain range, thus shaking.

I had this with my stock brakes after about 35K mi. I had them 'turned' at the Lexus dealer (thanks VVT-i!!!!) and it made ALL THE DIFFERENCE. Brakes were GLASS SMOOTH after that.

kam, go get it done. You'll be happy you did.

As far as the stock brakes, they're excellent. They feel a bit mushy if you have large or heavy rims, but as far as stopping power, they're REALLY good.

kam1996

Ok..Thanks guys..
I will get the rotors resurfaced or turned as soon as possible. I have to take the car in for some warranty work soon, so unless Lexus rate is totally unreasonable, I will have them resurfaced there..
Thbaks again and I will keep you all posted

doug_999

Interesting race story too. I seem to remember that Z4s with the 3.0 liter engine run low 14s. If it was a 3.0, I'll bet from a stop it would be a much closer race.

back to topic.. while I hate the feel/moderation ability of the GS brakes, when they hit, they stop really quick.

JYOO

I used to have bad shaking too from braking, had the rotors turned, and it all went away. I didn't even need new pads.

LXOGOOD

Ron430: I just looked in one of my Road & Track mags. A stock GS430 stops in 118 feet braking from 60mph. Here are some comparisons I found...

'03 M3 = 112 feet
'02 M5 = 116 feet
'03 Z4 = 113 feet

'03 Z06 = 114 feet
'03 E55 AMG = 118 feet
'03 Viper SRT-10 = 114 feet
'03 911 Carrera = 117 feet

I didn't realize how good the stock braking is on a GS. It compares to some of the best... It must have been fun racing your GS at Laguna Seca...

Kam: While you have your rotors resurfaced, make sure they tighten all your sway bar bolts as well. Loose bolts can result in major vibration in the steering wheel too. Good luck....

rominl

iTrader: (4)

oh yeah, the braking of GS is actually very very good. it's the soft feeling that kills the whole braking experience

RON430

Fortunately the driver can compensate for feel issues on the brakes.

D2-AUTOSPORT

As others have mentioned, alot of it has to do with the pads, and the condition of the brakes. I know you got your car used (as I did), and alot of these car re-sellers use the cheapest parts possible when going tuneups!

For instance- if he calls up the parts store, and they say 80 bucks for 100% organic, 95 for semi, and 110 for full metallic, guess which ones he's gonna use!!

I just put the Rotora Axxis ultimate pads and they perform alot better than the ones that I had TRUST ME!!!

Carboxy

Hi,
i brought a 2000 gs400. I notice a slight vibration when I brake. I had my rotor resurfaced and it stopped, but sometimes I feel a slight vibration again. the mechanic said I might need to replace my bolts for the front tires (10 bolts all together) b/c lexus bolts threading that hold the tires together might "stretched" under driving conditions. what do you guys think about what the mechanic said..
thanks
robert

Ex996

Hi- just finished a high speed road trip from SF to LA this weekend, and both my girlfriend and I noticed vibration when hauling down from 100mph to 70 or so. Car has 24k miles and I'm not a "brake rider."