SE5spd

iTrader: (17)

Better safe then sorry. BTW, how hard is this part to replace? is it doable at a track day between sessions if needed be?

sig11

iTrader: (3)

It's a fairly quick and easy job... 4 bolts after the rotor is off. I would consider it an easy trackside fix.

scotts300

iTrader: (46)

I have tracked this Z for almost 4 years now, including 60 track days and about 80 ax. At < $300/pair, I will start to change them each year.

You need a 22mm hex to get the calipers off, which I don't consider a common size. I think the 4 hub bolts are 17mm. One of them is a little tricky to get a grip on, but it's doable. The biggest challenge to getting them done between HPDE sessions (about an hour) is letting it all cool down enough that you can start to unbolt things. I missed one session, and I think that was good timing. Unless the session it failed on you was before lunch THEN you have an hour wait, I'd suggest you take your time, let things cool, get the torque set correctly, and miss one session.

betamotorsports

iTrader: (1)

I've changed pads and rotors in pit lane on Viper at Daytona. You wear two pairs of Kevlar gloves - below is the inner:

http://www.grainger.com/Grainger/IRO...rk-Glove-1PHG5

And this is the outer that gets destroyed and thrown away after the pit stop:

http://www.grainger.com/Grainger/CON...&cm_vc=IDPRRZ1

Voboy

iTrader: (58)

only if you started to hear it making some noise first! not a quick fix if your wheel falls off and sends you flying into a field!

Z33Garage

iTrader: (3)

Part out?

billstein87

iTrader: (3)

Hi folks,
I was in the NASA Spec Z race at Mid-Ohio 3 weeks ago and had a brake failure that totaled my car. Sorry I didn't post sooner but I wanted to get the data out of my car first to make sure it agreed with my recollection, and I was a bit hurt so I could barely move for 3 weeks. Now i see that my incident was earily similar to Jeff's that started this thread. I guess this is as good a place to post the data as any.

Facts backed up by data acquisition:
I had error codes for both front wheel speed sensors
Nissan speed data was wrong and inconsistent for multiple laps before the incident.
As I applied the brakes, Initially the braking was normal, but gently decreased for the first 0.8 seconds
After 0.8 seconds, the braking decreased to near zero almost instantaneously, with the brake lights illuminated for 0.7 seconds longer.
I immediately turned into the corner early as I let off the brakes.
I applied the brakes 2 more times during the turn, but no noticeable speed differential occurred.
The brake booster has no residue indicating a leaking master cyllinder (potential cause for booster failure), and even after the crash the booster still holds vacuum.

My 2 cents:
The pedal pushed back on me. I can't tell you if the pedal feel was pulsed pressure or smooth. I think it was smooth. Both additional times I hit the brakes, the pedal felt solid but nothing happened.
I have felt brakes without booster before. It did not feel like this. This felt like ZERO brakes, not decreased braking.
I beleive there is a software issue that allows the ABS to save you even if it has known wheel speed error(s). That would be a bad idea. I'm currently pressing to get Nissan to check the black box data, but I'm not having any luck. I won't go into that here....

I beleive that Jeff and I both probably had an ABS light on at the time of the crashes. My advice is not to race (or even drive) if you have an ABS light on. Though the chance of it happening to you is 1 in a thousand, the consequences are too large.

I hope this helps,
Bill


Update an hour later - There was a reply that seems missing from Laze1 questioning the effect of tire size. He made me realize I left out some info that is relative. I will say that I have run staggered, I have run 245 and 275 and 285 both in Hoosier and BFG with no issues. Jeff confirmed he had hub failure likely causing wheel speed sensor failure. I had an incident the day before with a Miata and brake marker cones that ripped everything apart under the car. That is likely the reason for my wheel speed sensor failures.
-bill

3hree5ive0ero

iTrader: (95)

This is some scary stuff. As our cars age, I'm hoping we won't see more of these problems, but it seems inevitable. Glad you guys are all ok, though.

thekinn

iTrader: (18)

Thanks for sharing. Hope for a fast and full recovery.

mw9

iTrader: (51)

Has anyone confirmed running these car without ABS, if the ABS is causing all these problems, just sounds like we need to eliminate it, if possible

NismoZ_840

iTrader: (3)

Sub'd, time to replace my hubs.

3hree5ive0ero

iTrader: (95)

Don't most of the competitive Miata guys do away with ABS because of reasons like this?

mhoward1

CMC, AIX, and many ST1 and ST2 guys also remove the ABS systems. Us in FFRC never had ABS, so we never missed it.

sfarrah

iTrader: (4)

Simply unplugging the ABS unit will not help as you lose front/rear brake bias immediately and rears lock up quite easily. If you do remove ABS you'll need to make sure you plumb in something for bias adjustment.

When my ABS unit went out on me a couple years ago it took a number of used ones to get one that worked. Was a pain to get one that worked but I wanted ABS mostly for racing in the rain and saving flat spotted tires. Seeing these huge wrecks caused by ABS issues certainly adds a check mark to the pro column of removing it all though.

laze1

iTrader: (17)

From the latest version of the Spec Z rules:

17 Brake System
17.1 Brake System
a) Brake pads are unrestricted.
b) Brake rotors must be the same type, material, and dimensions as OEM. Brake rotors from
alternate companies may be used. Brake rotors may be cryogenically treated.
c) Steel braided brake lines may be used.
d) Disc brake backing plates may be removed.
e) The emergency brake level and/or cables and associated must remain functional.
f) Anti-lock braking systems (ABS) may be disabled.
g) Nissan Motorsports front brake cooling kit part # may be utilized.

betamotorsports

iTrader: (1)

I think there are two separate issues here that some might be confusing:

1. Hub failure which triggers a wheel speed sensor failure more in the ABS system.
2. ABS "ice mode" failure.

The first is caused by a mechanical failure and really has nothing to do with the ABS system.

The second is a known software issue with not only 350Zs but Camaros, Corvettes, Mustangs, Vipers, Ferraris, etc. When the ABS system hits the limits of what they are programmed for they default into something we call "ice mode." This limit could be triggered by the car's dynamics or a sensor failure. Short of reprogramming the ABS system, drivers need to be aware of these limits and drive within them - very common in the old Showroom Stock racing series. Or remove the ABS system and make the necessary changes to reduce the heavy front brake bias.

scotts300

iTrader: (46)

Dug around the interwebs and found coupon code "APWPERCENT" for 10% off at Auto Parts Warehouse. I also called about the warranty, and one can purchase an extended 1, 3, or lifetime warranty, however, it does come with a 1-year warranty. When I prodded about enforcing the warranty, they indicated it had to be a manufacturing defect. Well, isn't it always a manufacturing defect? Point being, it's not likely we will be able to utilize any part of their warranty.

ThreeFiveZero Z

iTrader: (23)

Just wanted to throw in my two cents about ABS issues. I had been fighting an ABS light at the April and June NASA events, and could not figure it out. Bias was all off, car was braking funky, real scary. I had a Braile battery in the car that was showing signs of weakness. I swapped it back to a heavy Optima and it solved my issue. My conclusion was after talking to a few guys was that car does a pre-start abs computer check. If the voltage is low on the battery, the computer will bug out and throw the lamp when the car starts. Just an fyi.

2000atlanticgt

iTrader: (5)

Now you tell me after I already ordered and installed new hubs this week from them...

Really quick shipping and great customer service when I called to question them on delivery since I paid for overnight service to get them here and installed before my track day Saturday. They came on time even though at first they could not provide a tracking number but immediately told me they would refund the shipping charges if they did not arrive next day.

pro_350z

iTrader: (3)

damn!